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Dragonchain Great Reddit Scaling Bake-Off Public Proposal

Dragonchain Great Reddit Scaling Bake-Off Public Proposal

Dragonchain Public Proposal TL;DR:

Dragonchain has demonstrated twice Reddit’s entire total daily volume (votes, comments, and posts per Reddit 2019 Year in Review) in a 24-hour demo on an operational network. Every single transaction on Dragonchain is decentralized immediately through 5 levels of Dragon Net, and then secured with combined proof on Bitcoin, Ethereum, Ethereum Classic, and Binance Chain, via Interchain. At the time, in January 2020, the entire cost of the demo was approximately $25K on a single system (transaction fees locked at $0.0001/txn). With current fees (lowest fee $0.0000025/txn), this would cost as little as $625.
Watch Joe walk through the entire proposal and answer questions on YouTube.
This proposal is also available on the Dragonchain blog.

Hello Reddit and Ethereum community!

I’m Joe Roets, Founder & CEO of Dragonchain. When the team and I first heard about The Great Reddit Scaling Bake-Off we were intrigued. We believe we have the solutions Reddit seeks for its community points system and we have them at scale.
For your consideration, we have submitted our proposal below. The team at Dragonchain and I welcome and look forward to your technical questions, philosophical feedback, and fair criticism, to build a scaling solution for Reddit that will empower its users. Because our architecture is unlike other blockchain platforms out there today, we expect to receive many questions while people try to grasp our project. I will answer all questions here in this thread on Reddit, and I've answered some questions in the stream on YouTube.
We have seen good discussions so far in the competition. We hope that Reddit’s scaling solution will emerge from The Great Reddit Scaling Bake-Off and that Reddit will have great success with the implementation.

Executive summary

Dragonchain is a robust open source hybrid blockchain platform that has proven to withstand the passing of time since our inception in 2014. We have continued to evolve to harness the scalability of private nodes, yet take full advantage of the security of public decentralized networks, like Ethereum. We have a live, operational, and fully functional Interchain network integrating Bitcoin, Ethereum, Ethereum Classic, and ~700 independent Dragonchain nodes. Every transaction is secured to Ethereum, Bitcoin, and Ethereum Classic. Transactions are immediately usable on chain, and the first decentralization is seen within 20 seconds on Dragon Net. Security increases further to public networks ETH, BTC, and ETC within 10 minutes to 2 hours. Smart contracts can be written in any executable language, offering full freedom to existing developers. We invite any developer to watch the demo, play with our SDK’s, review open source code, and to help us move forward. Dragonchain specializes in scalable loyalty & rewards solutions and has built a decentralized social network on chain, with very affordable transaction costs. This experience can be combined with the insights Reddit and the Ethereum community have gained in the past couple of months to roll out the solution at a rapid pace.

Response and PoC

In The Great Reddit Scaling Bake-Off post, Reddit has asked for a series of demonstrations, requirements, and other considerations. In this section, we will attempt to answer all of these requests.

Live Demo

A live proof of concept showing hundreds of thousands of transactions
On Jan 7, 2020, Dragonchain hosted a 24-hour live demonstration during which a quarter of a billion (250 million+) transactions executed fully on an operational network. Every single transaction on Dragonchain is decentralized immediately through 5 levels of Dragon Net, and then secured with combined proof on Bitcoin, Ethereum, Ethereum Classic, and Binance Chain, via Interchain. This means that every single transaction is secured by, and traceable to these networks. An attack on this system would require a simultaneous attack on all of the Interchained networks.
24 hours in 4 minutes (YouTube):
24 hours in 4 minutes
The demonstration was of a single business system, and any user is able to scale this further, by running multiple systems simultaneously. Our goals for the event were to demonstrate a consistent capacity greater than that of Visa over an extended time period.
Tooling to reproduce our demo is available here:
https://github.com/dragonchain/spirit-bomb

Source Code

Source code (for on & off-chain components as well tooling used for the PoC). The source code does not have to be shared publicly, but if Reddit decides to use a particular solution it will need to be shared with Reddit at some point.

Scaling

How it works & scales

Architectural Scaling

Dragonchain’s architecture attacks the scalability issue from multiple angles. Dragonchain is a hybrid blockchain platform, wherein every transaction is protected on a business node to the requirements of that business or purpose. A business node may be held completely private or may be exposed or replicated to any level of exposure desired.
Every node has its own blockchain and is independently scalable. Dragonchain established Context Based Verification as its consensus model. Every transaction is immediately usable on a trust basis, and in time is provable to an increasing level of decentralized consensus. A transaction will have a level of decentralization to independently owned and deployed Dragonchain nodes (~700 nodes) within seconds, and full decentralization to BTC and ETH within minutes or hours. Level 5 nodes (Interchain nodes) function to secure all transactions to public or otherwise external chains such as Bitcoin and Ethereum. These nodes scale the system by aggregating multiple blocks into a single Interchain transaction on a cadence. This timing is configurable based upon average fees for each respective chain. For detailed information about Dragonchain’s architecture, and Context Based Verification, please refer to the Dragonchain Architecture Document.

Economic Scaling

An interesting feature of Dragonchain’s network consensus is its economics and scarcity model. Since Dragon Net nodes (L2-L4) are independent staking nodes, deployment to cloud platforms would allow any of these nodes to scale to take on a large percentage of the verification work. This is great for scalability, but not good for the economy, because there is no scarcity, and pricing would develop a downward spiral and result in fewer verification nodes. For this reason, Dragonchain uses TIME as scarcity.
TIME is calculated as the number of Dragons held, multiplied by the number of days held. TIME influences the user’s access to features within the Dragonchain ecosystem. It takes into account both the Dragon balance and length of time each Dragon is held. TIME is staked by users against every verification node and dictates how much of the transaction fees are awarded to each participating node for every block.
TIME also dictates the transaction fee itself for the business node. TIME is staked against a business node to set a deterministic transaction fee level (see transaction fee table below in Cost section). This is very interesting in a discussion about scaling because it guarantees independence for business implementation. No matter how much traffic appears on the entire network, a business is guaranteed to not see an increased transaction fee rate.

Scaled Deployment

Dragonchain uses Docker and Kubernetes to allow the use of best practices traditional system scaling. Dragonchain offers managed nodes with an easy to use web based console interface. The user may also deploy a Dragonchain node within their own datacenter or favorite cloud platform. Users have deployed Dragonchain nodes on-prem on Amazon AWS, Google Cloud, MS Azure, and other hosting platforms around the world. Any executable code, anything you can write, can be written into a smart contract. This flexibility is what allows us to say that developers with no blockchain experience can use any code language to access the benefits of blockchain. Customers have used NodeJS, Python, Java, and even BASH shell script to write smart contracts on Dragonchain.
With Docker containers, we achieve better separation of concerns, faster deployment, higher reliability, and lower response times.
We chose Kubernetes for its self-healing features, ability to run multiple services on one server, and its large and thriving development community. It is resilient, scalable, and automated. OpenFaaS allows us to package smart contracts as Docker images for easy deployment.
Contract deployment time is now bounded only by the size of the Docker image being deployed but remains fast even for reasonably large images. We also take advantage of Docker’s flexibility and its ability to support any language that can run on x86 architecture. Any image, public or private, can be run as a smart contract using Dragonchain.

Flexibility in Scaling

Dragonchain’s architecture considers interoperability and integration as key features. From inception, we had a goal to increase adoption via integration with real business use cases and traditional systems.
We envision the ability for Reddit, in the future, to be able to integrate alternate content storage platforms or other financial services along with the token.
  • LBRY - To allow users to deploy content natively to LBRY
  • MakerDAO to allow users to lend small amounts backed by their Reddit community points.
  • STORJ/SIA to allow decentralized on chain storage of portions of content. These integrations or any other are relatively easy to integrate on Dragonchain with an Interchain implementation.

Cost

Cost estimates (on-chain and off-chain) For the purpose of this proposal, we assume that all transactions are on chain (posts, replies, and votes).
On the Dragonchain network, transaction costs are deterministic/predictable. By staking TIME on the business node (as described above) Reddit can reduce transaction costs to as low as $0.0000025 per transaction.
Dragonchain Fees Table

Getting Started

How to run it
Building on Dragonchain is simple and requires no blockchain experience. Spin up a business node (L1) in our managed environment (AWS), run it in your own cloud environment, or on-prem in your own datacenter. Clear documentation will walk you through the steps of spinning up your first Dragonchain Level 1 Business node.
Getting started is easy...
  1. Download Dragonchain’s dctl
  2. Input three commands into a terminal
  3. Build an image
  4. Run it
More information can be found in our Get started documents.

Architecture
Dragonchain is an open source hybrid platform. Through Dragon Net, each chain combines the power of a public blockchain (like Ethereum) with the privacy of a private blockchain.
Dragonchain organizes its network into five separate levels. A Level 1, or business node, is a totally private blockchain only accessible through the use of public/private keypairs. All business logic, including smart contracts, can be executed on this node directly and added to the chain.
After creating a block, the Level 1 business node broadcasts a version stripped of sensitive private data to Dragon Net. Three Level 2 Validating nodes validate the transaction based on guidelines determined from the business. A Level 3 Diversity node checks that the level 2 nodes are from a diverse array of locations. A Level 4 Notary node, hosted by a KYC partner, then signs the validation record received from the Level 3 node. The transaction hash is ledgered to the Level 5 public chain to take advantage of the hash power of massive public networks.
Dragon Net can be thought of as a “blockchain of blockchains”, where every level is a complete private blockchain. Because an L1 can send to multiple nodes on a single level, proof of existence is distributed among many places in the network. Eventually, proof of existence reaches level 5 and is published on a public network.

API Documentation

APIs (on chain & off)

SDK Source

Nobody’s Perfect

Known issues or tradeoffs
  • Dragonchain is open source and even though the platform is easy enough for developers to code in any language they are comfortable with, we do not have so large a developer community as Ethereum. We would like to see the Ethereum developer community (and any other communities) become familiar with our SDK’s, our solutions, and our platform, to unlock the full potential of our Ethereum Interchain. Long ago we decided to prioritize both Bitcoin and Ethereum Interchains. We envision an ecosystem that encompasses different projects to give developers the ability to take full advantage of all the opportunities blockchain offers to create decentralized solutions not only for Reddit but for all of our current platforms and systems. We believe that together we will take the adoption of blockchain further. We currently have additional Interchain with Ethereum Classic. We look forward to Interchain with other blockchains in the future. We invite all blockchains projects who believe in decentralization and security to Interchain with Dragonchain.
  • While we only have 700 nodes compared to 8,000 Ethereum and 10,000 Bitcoin nodes. We harness those 18,000 nodes to scale to extremely high levels of security. See Dragonchain metrics.
  • Some may consider the centralization of Dragonchain’s business nodes as an issue at first glance, however, the model is by design to protect business data. We do not consider this a drawback as these nodes can make any, none, or all data public. Depending upon the implementation, every subreddit could have control of its own business node, for potential business and enterprise offerings, bringing new alternative revenue streams to Reddit.

Costs and resources

Summary of cost & resource information for both on-chain & off-chain components used in the PoC, as well as cost & resource estimates for further scaling. If your PoC is not on mainnet, make note of any mainnet caveats (such as congestion issues).
Every transaction on the PoC system had a transaction fee of $0.0001 (one-hundredth of a cent USD). At 256MM transactions, the demo cost $25,600. With current operational fees, the same demonstration would cost $640 USD.
For the demonstration, to achieve throughput to mimic a worldwide payments network, we modeled several clients in AWS and 4-5 business nodes to handle the traffic. The business nodes were tuned to handle higher throughput by adjusting memory and machine footprint on AWS. This flexibility is valuable to implementing a system such as envisioned by Reddit. Given that Reddit’s daily traffic (posts, replies, and votes) is less than half that of our demo, we would expect that the entire Reddit system could be handled on 2-5 business nodes using right-sized containers on AWS or similar environments.
Verification was accomplished on the operational Dragon Net network with over 700 independently owned verification nodes running around the world at no cost to the business other than paid transaction fees.

Requirements

Scaling

This PoC should scale to the numbers below with minimal costs (both on & off-chain). There should also be a clear path to supporting hundreds of millions of users.
Over a 5 day period, your scaling PoC should be able to handle:
*100,000 point claims (minting & distributing points) *25,000 subscriptions *75,000 one-off points burning *100,000 transfers
During Dragonchain’s 24 hour demo, the above required numbers were reached within the first few minutes.
Reddit’s total activity is 9000% more than Ethereum’s total transaction level. Even if you do not include votes, it is still 700% more than Ethereum’s current volume. Dragonchain has demonstrated that it can handle 250 million transactions a day, and it’s architecture allows for multiple systems to work at that level simultaneously. In our PoC, we demonstrate double the full capacity of Reddit, and every transaction was proven all the way to Bitcoin and Ethereum.
Reddit Scaling on Ethereum

Decentralization

Solutions should not depend on any single third-party provider. We prefer solutions that do not depend on specific entities such as Reddit or another provider, and solutions with no single point of control or failure in off-chain components but recognize there are numerous trade-offs to consider
Dragonchain’s architecture calls for a hybrid approach. Private business nodes hold the sensitive data while the validation and verification of transactions for the business are decentralized within seconds and secured to public blockchains within 10 minutes to 2 hours. Nodes could potentially be controlled by owners of individual subreddits for more organic decentralization.
  • Billing is currently centralized - there is a path to federation and decentralization of a scaled billing solution.
  • Operational multi-cloud
  • Operational on-premises capabilities
  • Operational deployment to any datacenter
  • Over 700 independent Community Verification Nodes with proof of ownership
  • Operational Interchain (Interoperable to Bitcoin, Ethereum, and Ethereum Classic, open to more)

Usability Scaling solutions should have a simple end user experience.

Users shouldn't have to maintain any extra state/proofs, regularly monitor activity, keep track of extra keys, or sign anything other than their normal transactions
Dragonchain and its customers have demonstrated extraordinary usability as a feature in many applications, where users do not need to know that the system is backed by a live blockchain. Lyceum is one of these examples, where the progress of academy courses is being tracked, and successful completion of courses is rewarded with certificates on chain. Our @Save_The_Tweet bot is popular on Twitter. When used with one of the following hashtags - #please, #blockchain, #ThankYou, or #eternalize the tweet is saved through Eternal to multiple blockchains. A proof report is available for future reference. Other examples in use are DEN, our decentralized social media platform, and our console, where users can track their node rewards, view their TIME, and operate a business node.
Examples:

Transactions complete in a reasonable amount of time (seconds or minutes, not hours or days)
All transactions are immediately usable on chain by the system. A transaction begins the path to decentralization at the conclusion of a 5-second block when it gets distributed across 5 separate community run nodes. Full decentralization occurs within 10 minutes to 2 hours depending on which interchain (Bitcoin, Ethereum, or Ethereum Classic) the transaction hits first. Within approximately 2 hours, the combined hash power of all interchained blockchains secures the transaction.

Free to use for end users (no gas fees, or fixed/minimal fees that Reddit can pay on their behalf)
With transaction pricing as low as $0.0000025 per transaction, it may be considered reasonable for Reddit to cover transaction fees for users.
All of Reddit's Transactions on Blockchain (month)
Community points can be earned by users and distributed directly to their Reddit account in batch (as per Reddit minting plan), and allow users to withdraw rewards to their Ethereum wallet whenever they wish. Withdrawal fees can be paid by either user or Reddit. This model has been operating inside the Dragonchain system since 2018, and many security and financial compliance features can be optionally added. We feel that this capability greatly enhances user experience because it is seamless to a regular user without cryptocurrency experience, yet flexible to a tech savvy user. With regard to currency or token transactions, these would occur on the Reddit network, verified to BTC and ETH. These transactions would incur the $0.0000025 transaction fee. To estimate this fee we use the monthly active Reddit users statista with a 60% adoption rate and an estimated 10 transactions per month average resulting in an approximate $720 cost across the system. Reddit could feasibly incur all associated internal network charges (mining/minting, transfer, burn) as these are very low and controllable fees.
Reddit Internal Token Transaction Fees

Reddit Ethereum Token Transaction Fees
When we consider further the Ethereum fees that might be incurred, we have a few choices for a solution.
  1. Offload all Ethereum transaction fees (user withdrawals) to interested users as they wish to withdraw tokens for external use or sale.
  2. Cover Ethereum transaction fees by aggregating them on a timed schedule. Users would request withdrawal (from Reddit or individual subreddits), and they would be transacted on the Ethereum network every hour (or some other schedule).
  3. In a combination of the above, customers could cover aggregated fees.
  4. Integrate with alternate Ethereum roll up solutions or other proposals to aggregate minting and distribution transactions onto Ethereum.

Bonus Points

Users should be able to view their balances & transactions via a blockchain explorer-style interface
From interfaces for users who have no knowledge of blockchain technology to users who are well versed in blockchain terms such as those present in a typical block explorer, a system powered by Dragonchain has flexibility on how to provide balances and transaction data to users. Transactions can be made viewable in an Eternal Proof Report, which displays raw data along with TIME staking information and traceability all the way to Bitcoin, Ethereum, and every other Interchained network. The report shows fields such as transaction ID, timestamp, block ID, multiple verifications, and Interchain proof. See example here.
Node payouts within the Dragonchain console are listed in chronological order and can be further seen in either Dragons or USD. See example here.
In our social media platform, Dragon Den, users can see, in real-time, their NRG and MTR balances. See example here.
A new influencer app powered by Dragonchain, Raiinmaker, breaks down data into a user friendly interface that shows coin portfolio, redeemed rewards, and social scores per campaign. See example here.

Exiting is fast & simple
Withdrawing funds on Dragonchain’s console requires three clicks, however, withdrawal scenarios with more enhanced security features per Reddit’s discretion are obtainable.

Interoperability Compatibility with third party apps (wallets/contracts/etc) is necessary.
Proven interoperability at scale that surpasses the required specifications. Our entire platform consists of interoperable blockchains connected to each other and traditional systems. APIs are well documented. Third party permissions are possible with a simple smart contract without the end user being aware. No need to learn any specialized proprietary language. Any code base (not subsets) is usable within a Docker container. Interoperable with any blockchain or traditional APIs. We’ve witnessed relatively complex systems built by engineers with no blockchain or cryptocurrency experience. We’ve also demonstrated the creation of smart contracts within minutes built with BASH shell and Node.js. Please see our source code and API documentation.

Scaling solutions should be extensible and allow third parties to build on top of it Open source and extensible
APIs should be well documented and stable

Documentation should be clear and complete
For full documentation, explore our docs, SDK’s, Github repo’s, architecture documents, original Disney documentation, and other links or resources provided in this proposal.

Third-party permissionless integrations should be possible & straightforward Smart contracts are Docker based, can be written in any language, use full language (not subsets), and can therefore be integrated with any system including traditional system APIs. Simple is better. Learning an uncommon or proprietary language should not be necessary.
Advanced knowledge of mathematics, cryptography, or L2 scaling should not be required. Compatibility with common utilities & toolchains is expected.
Dragonchain business nodes and smart contracts leverage Docker to allow the use of literally any language or executable code. No proprietary language is necessary. We’ve witnessed relatively complex systems built by engineers with no blockchain or cryptocurrency experience. We’ve also demonstrated the creation of smart contracts within minutes built with BASH shell and Node.js.

Bonus

Bonus Points: Show us how it works. Do you have an idea for a cool new use case for Community Points? Build it!

TIME

Community points could be awarded to Reddit users based upon TIME too, whereas the longer someone is part of a subreddit, the more community points someone naturally gained, even if not actively commenting or sharing new posts. A daily login could be required for these community points to be credited. This grants awards to readers too and incentivizes readers to create an account on Reddit if they browse the website often. This concept could also be leveraged to provide some level of reputation based upon duration and consistency of contribution to a community subreddit.

Dragon Den

Dragonchain has already built a social media platform that harnesses community involvement. Dragon Den is a decentralized community built on the Dragonchain blockchain platform. Dragon Den is Dragonchain’s answer to fake news, trolling, and censorship. It incentivizes the creation and evaluation of quality content within communities. It could be described as being a shareholder of a subreddit or Reddit in its entirety. The more your subreddit is thriving, the more rewarding it will be. Den is currently in a public beta and in active development, though the real token economy is not live yet. There are different tokens for various purposes. Two tokens are Lair Ownership Rights (LOR) and Lair Ownership Tokens (LOT). LOT is a non-fungible token for ownership of a specific Lair. LOT will only be created and converted from LOR.
Energy (NRG) and Matter (MTR) work jointly. Your MTR determines how much NRG you receive in a 24-hour period. Providing quality content, or evaluating content will earn MTR.

Security. Users have full ownership & control of their points.
All community points awarded based upon any type of activity or gift, are secured and provable to all Interchain networks (currently BTC, ETH, ETC). Users are free to spend and withdraw their points as they please, depending on the features Reddit wants to bring into production.

Balances and transactions cannot be forged, manipulated, or blocked by Reddit or anyone else
Users can withdraw their balance to their ERC20 wallet, directly through Reddit. Reddit can cover the fees on their behalf, or the user covers this with a portion of their balance.

Users should own their points and be able to get on-chain ERC20 tokens without permission from anyone else
Through our console users can withdraw their ERC20 rewards. This can be achieved on Reddit too. Here is a walkthrough of our console, though this does not show the quick withdrawal functionality, a user can withdraw at any time. https://www.youtube.com/watch?v=aNlTMxnfVHw

Points should be recoverable to on-chain ERC20 tokens even if all third-parties involved go offline
If necessary, signed transactions from the Reddit system (e.g. Reddit + Subreddit) can be sent to the Ethereum smart contract for minting.

A public, third-party review attesting to the soundness of the design should be available
To our knowledge, at least two large corporations, including a top 3 accounting firm, have conducted positive reviews. These reviews have never been made public, as Dragonchain did not pay or contract for these studies to be released.

Bonus points
Public, third-party implementation review available or in progress
See above

Compatibility with HSMs & hardware wallets
For the purpose of this proposal, all tokenization would be on the Ethereum network using standard token contracts and as such, would be able to leverage all hardware wallet and Ethereum ecosystem services.

Other Considerations

Minting/distributing tokens is not performed by Reddit directly
This operation can be automated by smart contract on Ethereum. Subreddits can if desired have a role to play.

One off point burning, as well as recurring, non-interactive point burning (for subreddit memberships) should be possible and scalable
This is possible and scalable with interaction between Dragonchain Reddit system and Ethereum token contract(s).

Fully open-source solutions are strongly preferred
Dragonchain is fully open source (see section on Disney release after conclusion).

Conclusion

Whether it is today, or in the future, we would like to work together to bring secure flexibility to the highest standards. It is our hope to be considered by Ethereum, Reddit, and other integrative solutions so we may further discuss the possibilities of implementation. In our public demonstration, 256 million transactions were handled in our operational network on chain in 24 hours, for the low cost of $25K, which if run today would cost $625. Dragonchain’s interoperable foundation provides the atmosphere necessary to implement a frictionless community points system. Thank you for your consideration of our proposal. We look forward to working with the community to make something great!

Disney Releases Blockchain Platform as Open Source

The team at Disney created the Disney Private Blockchain Platform. The system was a hybrid interoperable blockchain platform for ledgering and smart contract development geared toward solving problems with blockchain adoption and usability. All objective evaluation would consider the team’s output a success. We released a list of use cases that we explored in some capacity at Disney, and our input on blockchain standardization as part of our participation in the W3C Blockchain Community Group.
https://lists.w3.org/Archives/Public/public-blockchain/2016May/0052.html

Open Source

In 2016, Roets proposed to release the platform as open source to spread the technology outside of Disney, as others within the W3C group were interested in the solutions that had been created inside of Disney.
Following a long process, step by step, the team met requirements for release. Among the requirements, the team had to:
  • Obtain VP support and approval for the release
  • Verify ownership of the software to be released
  • Verify that no proprietary content would be released
  • Convince the organization that there was a value to the open source community
  • Convince the organization that there was a value to Disney
  • Offer the plan for ongoing maintenance of the project outside of Disney
  • Itemize competing projects
  • Verify no conflict of interest
  • Preferred license
  • Change the project name to not use the name Disney, any Disney character, or any other associated IP - proposed Dragonchain - approved
  • Obtain legal approval
  • Approval from corporate, parks, and other business units
  • Approval from multiple Disney patent groups Copyright holder defined by Disney (Disney Connected and Advanced Technologies)
  • Trademark searches conducted for the selected name Dragonchain
  • Obtain IT security approval
  • Manual review of OSS components conducted
  • OWASP Dependency and Vulnerability Check Conducted
  • Obtain technical (software) approval
  • Offer management, process, and financial plans for the maintenance of the project.
  • Meet list of items to be addressed before release
  • Remove all Disney project references and scripts
  • Create a public distribution list for email communications
  • Remove Roets’ direct and internal contact information
  • Create public Slack channel and move from Disney slack channels
  • Create proper labels for issue tracking
  • Rename internal private Github repository
  • Add informative description to Github page
  • Expand README.md with more specific information
  • Add information beyond current “Blockchains are Magic”
  • Add getting started sections and info on cloning/forking the project
  • Add installation details
  • Add uninstall process
  • Add unit, functional, and integration test information
  • Detail how to contribute and get involved
  • Describe the git workflow that the project will use
  • Move to public, non-Disney git repository (Github or Bitbucket)
  • Obtain Disney Open Source Committee approval for release
On top of meeting the above criteria, as part of the process, the maintainer of the project had to receive the codebase on their own personal email and create accounts for maintenance (e.g. Github) with non-Disney accounts. Given the fact that the project spanned multiple business units, Roets was individually responsible for its ongoing maintenance. Because of this, he proposed in the open source application to create a non-profit organization to hold the IP and maintain the project. This was approved by Disney.
The Disney Open Source Committee approved the application known as OSSRELEASE-10, and the code was released on October 2, 2016. Disney decided to not issue a press release.
Original OSSRELASE-10 document

Dragonchain Foundation

The Dragonchain Foundation was created on January 17, 2017. https://den.social/l/Dragonchain/24130078352e485d96d2125082151cf0/dragonchain-and-disney/
submitted by j0j0r0 to ethereum [link] [comments]

Collapse of MakerDAO Keepers: $4.5M lost & how to become a Keeper to earn 13%+ liquidation penalties by providing liquidity to MakerDAO Keeper Pool.

TL;DR - join waitlist for MakerDAO Keeper Pool to earn yield on DAI/ETH/USDC/USDT/Chai/sUSD/cDAI from liquidation penalties and ETH/DAI arbitrage profits earned in collateral auctions by the Keeper Pool (zero fee pool, non-custodial of course:) - https://docs.google.com/forms/d/e/1FAIpQLSfekQcjT5up5Uh2W_C2W0U5zJ5miLd5ott_87CW8-dDH75TZg/viewform
________
Unfortunately, many of us became victims of MakerDAO collateral auctions market. This market was brought to its knees today, resulting in:
1) Losses affecting some of the MakerDAO Vault holders (borrowers of DAI from the Multi-Collateral DAI system), and
2) Losses affecting 100% of MKR token holders, - minting enough MKR and selling them for DAI to cover the missing DAI in the system. The auctions will begin on Wednesday, March 18, 2020.
For the last 14 hours I've been focusing on determining the root cause of the problem, and determining WHAT CAN I DO? to prevent this collapse from ever happening again.
Collapse of the MakerDAO Auctions.
Losses above is a result of a short-term monopoly in the auction market of collateral liquidation of MakerDAO vaults becoming under-collateralized with price of collateral (ETH, BAT) on the decline. This monopoly existed for ~3.5 hours this morning, allowing a single Keeper to buy close to $4.5M worth of ETH in exchange for ~0 DAI + gas fees.
The collapse negatively affected two classes of market participants:
1) Victim class #1: MCD Vault holders who were being liquidated between ~10am EST until ~1pm EST
Please meet Paul, one of the people who lost money. Read his story:
https://www.reddit.com/MakerDAO/comments/fhn1qn/complete_vault_liquidation_no_eth_left/
If you still didn't get it, please meet BitBurst who lost his life savings today:
https://www.reddit.com/MakerDAO/comments/fhs7kp/just_got_100_liquidated_with_my_1713_eth_cdp_fck/
Want more? One of us with a Reddit handle 'phyzled' is calling for help:
https://www.reddit.com/MakerDAO/comments/fhrjxp/help_complete_liquidation/
Even 'Bitcoin_Bender' is threatened. Not just him but his life and his family are going downhill:
https://www.reddit.com/MakerDAO/comments/fhupn8/total_liquidation_mkr_holders_should_take/
2) Victim class #2: MKR holders who will be diluted on Wednesday, March 18th as a result of Flop auction - minting new MKR tokens and selling them at an auction until the auction proceeds cover the missing DAI ($4.5M DAI at the time of this writing).
WHAT HAPPENED?
Prior to ~10am EST, there were a lot of Keepers bidding against each other for collateral at 13% liquidation penalty. Keepers are software bots which monitor Vaults and participate in auctions for collateral of borrowers who became under-collateralized. Operators of such bots are incentivized with mandatory 13% liquidation penalty imposed on Vault collateral upon liquidation.
https://docs.makerdao.com/auctions/the-auctions-of-the-maker-protocol
https://docs.makerdao.com/smart-contract-modules/collateral-module/flipper-detailed-documentation
However, after 10am EST, a single liquidation auction bot was able to bid at 0 DAI (or slightly above) PER EACH COLLATERAL ETH BEING AUCTIONED, AND WIN THE AUCTION. As a result, this Keeper was effectively steal $4M worth of ETH collateral because the auction was designed to raise at least 4M DAI in exchange for the ETH that was auctioned during liquidations, however all except one Keepers stopping their operations, there was only one bidder. Any price above 0 would be accepted. As a result, but the Vault holders who supposed to receive some ETH back, never got any ETH back > making the effective liquidation penalty to over 50% instead of 13%.
Why did the Keeper's market collapse? Why most Keepers stop operating?
Unfortunately, most Keepers stopped operating this morning due to the following reasons:
Root cause #1: Catastrophic liquidity crunch. Keepers simply ran out of DAI to bid in the collateral auctions due to
1.a I believe some Keepers were unable to continue Keeper operations due to inability to liquidate ETH fast enough for DAI.
1.b Some Keepers shut down due to squeeze (bought ETH for 170 DAI, and hours later can only sell for 130 DAI at a loss - which is way more than 13% liquidation penalty).
Root cause #2: Network congestion. This brought many Keepers to its knees. Even with liquidity, many were unable participating in auctions due to stuck transactions & high gas costs. In addition, issues like longer client sync times + some Ethereum clients (like Parity) sufferring from known problems of keeping transactions stuck in Mempool for a very, very long time, amplified this problem.
PROPOSED SOLUTION - MakerDAO Keeper Pool.
Why don't we pool our liquidity (non-custodial pool, Uniswap-style) and give Keepers some competition!?
To prevent more people from losing their funds, I decided to fund development of a MakerDAO Keeper Pool, which will allow anybody to become a Keeper and participate in liquidations of collateral (to earn 13% liquidation penalty).
Background: During today’s Community Call (5 hours and still ongoing at the time of this writing), multiple members of the Maker community stressed importance of increasing # of Keepers servicing the MCD system in order to prevent yet another collapse of the Keepers market as it happened today.
To improve maturity of the Keepers market, increase the collective liquidity used by Keeper’s, engineers at Protofire.io (developers of MakerDAO governance dashboard https://mkrgov.science, Solhint - Solidity Linter https://github.com/protofire/solhint, maintainers of Gnosis Conditional Exchange https://github.com/protofire/gnosis-conditional-exchange) and risk team + engineering team at Atomica.org (developers of Atomica.org/unwind/) launched emergency efforts to ship one or more of the following ASAP:
  1. Web-based MakerDAO Keeper. Perform liquidations of 3rd party collateral from your browser as a Keeper. Earn 13% liquidation penalty.
  2. Open Source Keeper Templates. Run your own Keeper Bot on AWS - 1-click Installer for a MakerDAO Keeper Bot (open source Amazon Machine Image).
  3. Non-custodial MakerDAO Keeper Pool. Earn yield on DAI/ETH/USDC/USDT/cDAI/Chai from a pool running multiple Keeper bots servicing MakerDAO ecosystem. Join/Exit/Add/Withdraw DAI/ETH/USDC/USDT/cDAI/Chai, and earn 100% of liquidation penalties earned by the Keeper (zero fee pool).
Ultimately, we aim to:
- Upgrade the MakerDAO Keeper Pool to be a Keeper of Last Resort. Think of a Keeper backed by on-chain, guaranteed liquidity AND configured to participate in auctions with bids of at least 0.85 of the current ETH-DAI market price, as reported by oracles. So long as the Keeper Pool is operating, no Keeper will be able to take advantage of the system and cause yet another collapse of the MakerDAO Collateral Auction markets.
- Ship 3rd party JavaScript / npm library + Android/iOS SDKs to embed Web-based Keeper or MakerDAO Keeper Pool join/exit/add/withdraw liquidity into your own dApp, protocol, product or service.
If anyone is interested in developing/observing/joining MakerDAO Keeper Pool (for example by running their own Keeper using hardened AWS AMI template, or by providing liquidity (DAI/ETH/USDC/USDT/cDAI/Chai) to a Keeper Pool) - feel free to join our working group working to ship a MakerDAO Keeper Pool ASAP - https://docs.google.com/forms/d/e/1FAIpQLSfekQcjT5up5Uh2W_C2W0U5zJ5miLd5ott_87CW8-dDH75TZg/viewform
Its not about what DeFi can do for you. It is about what YOU can do for DeFi.
submitted by renatco to ethereum [link] [comments]

Collapse of MakerDAO Auctions: $4.5M lost & how to become a Keeper to earn 13%+ liquidation penalties by providing liquidity to MakerDAO Keeper Pool.

TL;DR - join waitlist for MakerDAO Keeper Pool to earn yield on DAI/ETH/USDC/USDT/Chai/sUSD/cDAI from liquidation penalties and ETH/DAI arbitrage profits earned in collateral auctions by the Keeper Pool (zero fee pool, non-custodial of course:) - https://docs.google.com/forms/d/e/1FAIpQLSfekQcjT5up5Uh2W_C2W0U5zJ5miLd5ott_87CW8-dDH75TZg/viewform
________
Unfortunately, many of us became victims of MakerDAO collateral auctions market. This market was brought to its knees today, resulting in:
1) Losses affecting some of the MakerDAO Vault holders (borrowers of DAI from the Multi-Collateral DAI system), and
2) Losses affecting 100% of MKR token holders, - minting enough MKR and selling them for DAI to cover the missing DAI in the system. The auctions will begin on Wednesday, March 18, 2020.
For the last 14 hours I've been focusing on determining the root cause of the problem, and determining WHAT CAN I DO? to prevent this collapse from ever happening again.
Collapse of the MakerDAO Auctions.
Losses above is a result of a short-term monopoly in the auction market of collateral liquidation of MakerDAO vaults becoming under-collateralized with price of collateral (ETH, BAT) on the decline. This monopoly existed for ~3.5 hours this morning, allowing a single Keeper to buy close to $4.5M worth of ETH in exchange for ~0 DAI + gas fees.
The collapse negatively affected two classes of market participants:
1) Victim class #1: MCD Vault holders who were being liquidated between ~10am EST until ~1pm EST
Please meet Paul, one of the people who lost money. Read his story:
https://www.reddit.com/MakerDAO/comments/fhn1qn/complete_vault_liquidation_no_eth_left/
If you still didn't get it, please meet BitBurst who lost his life savings today:
https://www.reddit.com/MakerDAO/comments/fhs7kp/just_got_100_liquidated_with_my_1713_eth_cdp_fck/
Want more? One of us with a Reddit handle 'phyzled' is calling for help:
https://www.reddit.com/MakerDAO/comments/fhrjxp/help_complete_liquidation/
Even 'Bitcoin_Bender' is threatened. Not just him but his life and his family are going downhill:
https://www.reddit.com/MakerDAO/comments/fhupn8/total_liquidation_mkr_holders_should_take/
2) Victim class #2: MKR holders who will be diluted on Wednesday, March 18th as a result of Flop auction - minting new MKR tokens and selling them at an auction until the auction proceeds cover the missing DAI ($4.5M DAI at the time of this writing).
WHAT HAPPENED?
Prior to ~10am EST, there were a lot of Keepers bidding against each other for collateral at 13% liquidation penalty. Keepers are software bots which monitor Vaults and participate in auctions for collateral of borrowers who became under-collateralized. Operators of such bots are incentivized with mandatory 13% liquidation penalty imposed on Vault collateral upon liquidation.
https://docs.makerdao.com/auctions/the-auctions-of-the-maker-protocol
https://docs.makerdao.com/smart-contract-modules/collateral-module/flipper-detailed-documentation
However, after 10am EST, a single liquidation auction bot was able to bid at 0 DAI (or slightly above) PER EACH COLLATERAL ETH BEING AUCTIONED, AND WIN THE AUCTION. As a result, this Keeper was effectively steal $4M worth of ETH collateral because the auction was designed to raise at least 4M DAI in exchange for the ETH that was auctioned during liquidations, however all except one Keepers stopping their operations, there was only one bidder. Any price above 0 would be accepted. As a result, but the Vault holders who supposed to receive some ETH back, never got any ETH back > making the effective liquidation penalty to over 50% instead of 13%.
Why did the Keeper's market collapse? Why most Keepers stop operating?
Unfortunately, most Keepers stopped operating this morning due to the following reasons:
Root cause #1: Catastrophic liquidity crunch. Keepers simply ran out of DAI to bid in the collateral auctions due to
1.a I believe some Keepers were unable to continue Keeper operations due to inability to liquidate ETH fast enough for DAI.
1.b Some Keepers shut down due to squeeze (bought ETH for 170 DAI, and hours later can only sell for 130 DAI at a loss - which is way more than 13% liquidation penalty).
Root cause #2: Network congestion. This brought many Keepers to its knees. Even with liquidity, many were unable participating in auctions due to stuck transactions & high gas costs. In addition, issues like longer client sync times + some Ethereum clients (like Parity) sufferring from known problems of keeping transactions stuck in Mempool for a very, very long time, amplified this problem.
PROPOSED SOLUTION - MakerDAO Keeper Pool.
Why don't we pool our liquidity (non-custodial pool, Uniswap-style) and give Keepers some competition!?
To prevent more people from losing their funds, I decided to fund development of a MakerDAO Keeper Pool, which will allow anybody to become a Keeper and participate in liquidations of collateral (to earn 13% liquidation penalty).
Background: During today’s Community Call (5 hours and still ongoing at the time of this writing), multiple members of the Maker community stressed importance of increasing # of Keepers servicing the MCD system in order to prevent yet another collapse of the Keepers market as it happened today.
To improve maturity of the Keepers market, increase the collective liquidity used by Keeper’s, engineers at Protofire.io (developers of MakerDAO governance dashboard https://mkrgov.science, Solhint - Solidity Linter https://github.com/protofire/solhint, maintainers of Gnosis Conditional Exchange https://github.com/protofire/gnosis-conditional-exchange) and risk team + engineering team at Atomica.org (developers of Atomica.org/unwind/) launched emergency efforts to ship one or more of the following ASAP:
  1. Web-based MakerDAO Keeper. Perform liquidations of 3rd party collateral from your browser as a Keeper. Earn 13% liquidation penalty.
  2. Open Source Keeper Templates. Run your own Keeper Bot on AWS - 1-click Installer for a MakerDAO Keeper Bot (open source Amazon Machine Image).
  3. Non-custodial MakerDAO Keeper Pool. Earn yield on DAI/ETH/USDC/USDT/cDAI/Chai from a pool running multiple Keeper bots servicing MakerDAO ecosystem. Join/Exit/Add/Withdraw DAI/ETH/USDC/USDT/cDAI/Chai, and earn 100% of liquidation penalties earned by the Keeper (zero fee pool).
Ultimately, we aim to:
- Upgrade the MakerDAO Keeper Pool to be a Keeper of Last Resort. Think of a Keeper backed by on-chain, guaranteed liquidity AND configured to participate in auctions with bids of at least 0.85 of the current ETH-DAI market price, as reported by oracles. So long as the Keeper Pool is operating, no Keeper will be able to take advantage of the system and cause yet another collapse of the MakerDAO Collateral Auction markets.
- Ship 3rd party JavaScript / npm library + Android/iOS SDKs to embed Web-based Keeper or MakerDAO Keeper Pool join/exit/add/withdraw liquidity into your own dApp, protocol, product or service.
If anyone is interested in developing/observing/joining MakerDAO Keeper Pool (for example by running their own Keeper using hardened AWS AMI template, or by providing liquidity (DAI/ETH/USDC/USDT/cDAI/Chai) to a Keeper Pool) - feel free to join our working group working to ship a MakerDAO Keeper Pool ASAP - https://docs.google.com/forms/d/e/1FAIpQLSfekQcjT5up5Uh2W_C2W0U5zJ5miLd5ott_87CW8-dDH75TZg/viewform
Its not about what DeFi can do for you. It is about what YOU can do for DeFi.
submitted by renatco to defi [link] [comments]

LIVE Beijing Conference June 22, 2017: English Translation

Me and my partner are going to do English play by play here. Tickets were around 570 each, so if you found this helpful , please donate.
2:10 Checked in. Around 100 guests attending so far. Conference should officially start in 20 mins.
2:30 Conference started. Currently in the Microsoft Beijing Office Lobby. Just introductions so far. The video trailer they played before the conference was quite impressive and in English.
2:32 srikanth Raju is speaking in English. You guys are good for this part. Big point: Microsoft believes in a heterogeneous Blockchain environment for Azure. Mentioned​ Ethereum specifically coexisting with antshares.
2:41 Skipped Jiang Li, Microsoft senior consultant's section for some reason.
2:45 Feng han is talking about the rise of alipay and transactions becoming electronic. Believes that full automation is the next step. Alibaba is still only half automated in their logistics. Huawei is interested in building smart cities, and will need blockchain. Note: they aren't announcing a partnership. Just talking about it.
2:51 Feng han talking about current internet infrastructure not being safe for the futures smart infrastructure. Then talked about a class offered by a genius cryptography professor, wangxiaoyun at tsinghua. Made a joke about 300x returns since ICO.
2:57 Hongfei Da. Talking about bitcoin and history of crypto. Now talking about founding of Antshares. Discussing dBFT and consensus briefly. Now talking about ICO. State of AntShares: 432 nodes, 1058300 blocks, main env running for 150 days. 352 stars on GitHub. LOL talking about this subreddit specifically now. Coinmarketcap ranking.
All assets will be digitized. Two categories: 1. Proof of existence is on the blockchain. 2. Off chain physical assets like IDs, bikeshare locks, intellectual property.
Spirit of blockchain isn't decentralization. It is transparency and fairness via publicly agreed upon rules and data.
Mantra: digital asset + digital ID + smart contract = smart economy.
REBRANDING: NEO smart economy. Green logo
Neo contracts with C#, Java/kotlin, python, go
NeoX is like an interledger protocol
NeoQ is quantum safe encryption
NeoFS is a new database layer
Emphasized ecosystem partnership with bancor agrello matchpool
Missed some points because too fast. Will go back later.
3:28 innospace CEO talking. Selected AntShares to join a pool of 10 companies out of 800 applicants. Best companies get 100x growth. Talked about Neo contracts active dev community and emphasized fintrch fundamental paper.
3:35 Alex norta from agrello. English speaking. Introducing the agrello platform currently. Announced new white paper finished today and ICO occurring now.
3:43 Adam from Coindash. Marketing Coindash as a onestop crypto portfolio that enables social trading and facilitates ICOs. Gives test runs for ICOs and let's you gauge interest. Announcing foray into China with close partnership with NEST partnership.
3:59 they made a reference to the matrix where they all pushed buttons and the screen said, WAKE UP NEO
4:00 break for 30 mins
4:31 restarting. CTO of AntShares speaking. Explaining smart contracts. Telling a story about Coke vending machine software executing a smart contract, except it ate his money because of a malicious party blocking the coin entry. Blockchain is necessary to allow smart contracts to be executed fairly.
Neo is different from Eth and fabric because it has static contract calls, deterministic blockchain network calls, and uses oracle's instead of internet API calls. Example, different nodes will have different Google search results based off of IP location.
NeoVM vs EthVM vs Docker Dyanmic sharding for NeoVM makes parallel processing scale better than EVM which has static sharding. Variables in NeoVM are determined beforehand and then the sharding is done before computation as opposed to EVM which divides work inflexibly.
EVM has high coupling (bad). NVM has low coupling like docker. Execution of contracts depends too much on the nodes and blockchain. This point wasn't too clear. Coupling seems to be a concept that people don't talk about often. Sounds like he was saying that you need to run eth smart contracts on a test blockchain environment while NeoVM allows you to test and run code independent of blockchain.
Microsoft offers IDE plugins and compilers to help people develop on the Neo platform.
Digital certificate issuance and asset digitization are supported in Neo but not inherently in Eth.
Storage layer for contracts is built into Neo. You can give authorization for others to read or write your contract storage space. Also, if your contract has a bug, you can take the data and migrate it to a patched contract. Lastly, allows rental of storage space for contracts. No support for any of the three points above in EVM.
Giving example of locking an account for a period of time. Showing decentralized domains. Sounds a lot like Eth name service.
5:21 bijie tech CEO. Talking about Binance ICO. Introducing the Binance team. Binance is a coin to coin centralized exchange. Made a joke about not wanting to ICO but did it after seeing everyone elses valuations.
5:35 fangzhou charity entrepreneur. Became a multimillionaire after getting some ANS.
Money is freedom. Now wants to give charity loans to kids that need an operation but parents don't have the money. Because of new Chinese laws only 113 out of 500 NGOs can receive donation money. Therefore the market for charity is undersupplied by organizations that can use the money.
5:46 xiaobai medical founder
No fixed location, employees or resources. Wants to make a medical system where people record their illnesses and compare outcomes with other patients to determine what is the best treatment. Can also match patients with doctors. Sounds like a combo of ZocDoc and patientory.
5:55 nest smart fund founder
Problems of most funds are lack of liquidity, inability to participate in the invested company, and high management cost.
DAO on ethereum was hacked, but NEST wants to do what DAO does but more safely and more transparently. They choose C# ( made a joke about being at Microsoft and using C#).
Going to make a nest coin that is redeemable for some of the coins that the project backs.
.................................
Questions:
what's going to happen to ANS?
AntShares will retire and get redistributed as NEO in the new wallet software. You don't have to do anything. No reissue so investors don't get screwed. Exchanges will get contacted automatically.
How many devs do you have now?
2 full time devs. They are going to offer NEO bounties on code and hire more.
New exchange announcement?
Binance
.................................
DONE
.,..............................
ETH donation address: 0x92CBE3Ae9ECB30Fa52BE536d55616571380c43b5
LTC donation address: LZXsdjZJJBWpAx7VQmQ4turVrvgBJwguru
ANS donation address: ARA25KDeQMbcR7nAAjTbbnf3pkW98etD2U
submitted by miaharles to Antshares [link] [comments]

I Put Code For Three Popular Cryptocurrencies Through Static Code Analysis—With Surprising Results

TL;DR — Professional developers, what is your code review feedback for this code?
I recently assigned myself an ad hoc learning exercise to try and figure out how Bitcoin Cash SV (BSV) and Bitcoin Cash ABC (BCH) client software determine whether or not they're working on a compatible network; communicating with compatible peers.
In the process, I came across 1500+-1600+ line-long methods. That surprised me.
I'm a developer myself. Java's my main language. I've never coded anything in the crypto domain. But I am conversant in a few other programming languages besides Java. Super long methods and super long classes are frowned upon, generally, as bad practice.
I was expecting to see super high quality coding practices in these kinds of projects. I was disappointed. At least by the code I discovered in those two particular cpp files, anyway.
In the majority of the commercial software development projects I have worked on, so-called god classes and methods more than one hundred lines long are generally considered to lower the quality of the code base. That's because they make maintaining the code 1) more difficult and 2) more expensive in the long run.
I took the Bitcoin (BTC) code on which both the above BSV and BCH implementations are based, and put it through an industry standard code quality analyzer.
The results reported issues with such unflattering descriptions as:
One method in the above-linked cpp files, had a Cognitive Complexity score twenty-one times higher than what is considered acceptable. In a nutshell, Cognitive Complexity is a mathematical, objective measure of how confusing something is. The idea being, the more confusing code is, the more difficult and more expensive it is to maintain.
Overall, the BSV, BTC and BCH code I've perused so far, is not the worse code I've ever seen in my life. But for some reason, I was expecting I would look at it and discover it was the most exemplary code I'd ever seen. It's not.
The pragmatist in me appreciates the value of working software over stylistic ideals. But because I was hoping to learn some new expert coding approaches from this code, I was kinda disappointed to discover the code is as mediocre as it is.
I'm curious to hear other devs' thoughts on the value of code quality.
submitted by modernDayPablum to BitcoinTechnology [link] [comments]

Disk Digger Pro Apk || DiskDigger Importance || Recover Lost Files

In the Present scenario, Technology is growing too fast and we all are experiencing that our smartphone, PC, and Laptops carrying various files with the help of SD cards and internal memory. We will think that our files are in very secure places but if any file deleted unexpectedly then what you will do?. Don't worry, I already told you that tech is growing as fast as it can. Here I'm going to discuss the best data recovery services aka (DiskDigger) which are a perfect example of it. Let's go down to get more details of DiskDigger( Deep file recovery from any drive).
DiskDigger is a tool which can recover deleted files like photos, documents, music, video and much more.
DiskDigger Features:
DiskDigger can recover lost files from most types of media that your computer can read: hard disks, USB flash drives, memory cards, CDs, DVDs, and floppy disks. (Note: Make sure that you have to connect your device with a USB port to recover lost data from Android and IOS devices ). And one more important thing is you have to download the diskdigger app on your android phone to recover lost files. Suppose if your Android device uses a microSD card for saving the data, please remove the card and connect it directly to your PC using a card reader, so that you can scan it directly using DiskDigger for Windows.)
DiskDigger has two processes which you have to choose every time while scanning a disk. These methods are named as “dig deep” and “dig deeper“.
Dig Deep:
Dig Deeper:
Advanced Features
To find more information go through remaining articles in our site like hard drive data recovery, SD card data Recovery, Android Data Recovery, USB flash drive data recovery, Linux Data Recovery etc.
submitted by diskdiggerproapk to u/diskdiggerproapk [link] [comments]

Stream REST API into kakfa

I want to build a streaming system which takes the bitcoin courses from different exchange platforms and compares courses in real time. For the latter part I probably would want to use flink (maybe beam). But the first part of how to ingest the data is not really clear to me.
To connect to an index once using https://github.com/timmolteXChange is demonstrated in the snippet below
val currencyPair = new CurrencyPair(Currency.XMR, Currency.BTC) CertHelper.trustAllCerts() val poloniex = ExchangeFactory.INSTANCE.createExchange(classOf[PoloniexExchange].getName) val dataService = poloniex.getMarketDataService generic(dataService) raw(dataService.asInstanceOf[PoloniexMarketDataServiceRaw]) System.out.println(dataService.getTicker(currencyPair)) 
I am really unsure how to create a steam from it which would allow low latency processing (and an overall simple architecture). So far I have seen http://stackoverflow.com/questions/39857922/apache-flume-vs-apache-flink-difference which suggests to not use flink to ingest/access the data.
Probably the overall architecture would look like X -> Kafka -> stream processor.
Which path to move forward would you suggest?
submitted by geoheil to dataengineering [link] [comments]

[Table] IamA founder of Tindie, "Etsy for Tech". Started on /r/Arduino, team of 5, just finished fundraising (pitching 50+ investors), and have now closed $1m+ in funding. This is a follow up to last year's AMA, for anyone interested in startups/tech/Silicon Valley/open hardware. AMA!

Verified? (This bot cannot verify AMAs just yet)
Date: 2013-12-02
Link to submission (Has self-text)
Questions Answers
As a maker, why should I sell my goods on your site instead of amazon? As a buyer, why should I buy from you instead of amazon/ebay? Great questions - as a maker, our rates are lower than Amazon - flat 5% of the order. We also reach a core audience of people like you, which tends to mean you'll sell more on Tindie vs Amazon. As an example, one seller sold exclusively on Amazon, opened a Tindie store, and we began out selling Amazon. He closed his Amazon store and now sells exclusively on Tindie.
As a buyer, you are joining a community of likeminded people from all over the world and in different niches. Some like audio, some drones, others lighting. In the new year we are launching more features to build out the community side of the site. We are a community marketplace - community comes first. We can do a better job on the community side, and those features are currently being built.
As an example, one seller sold exclusively on Amazon, opened a Tindie store, and we began out selling Amazon. He closed his Amazon store and now sells exclusively on Tindie. Amazon has a flat fee you must pay $40 a month When you sell out many times over, inventory management becomes a huge issue.
Many reasons but here are two- * * Amazon has a flat fee you must pay $40 a month.* Easier inventory management when you have to just make sure 1 site is right vs multiple. When you sell out many times over, inventory management becomes a huge issue. But, that's three reasons. How can you run a successful business if you can't even count? Link to static.fjcdn.com
I have a desire to learn a programming language and have messed around with python and java on codeacademy. What would you recommend as the next step? Books? More beginner tutorials? Poking around on github? Sounds like you are now at the crossroad where people either keep going, or 'never have the time.' When I started, I'd get the occasional comment online, 'You'll never figure it out.' It's a pretty accurate statement for most. Most don't figure it out. If you can put your head down and just grit it out, you'll get to the other side.
If you want to grit it out, start with Learn Python the Hard Way. Then figure out a project you want to build and go build it. You'll pick things up as you go. You'll think you have it about 10 times before you really have a solid understanding. There were many times I'd talk to my friends and say "Oh I figured it out." I was wrong 10 times :)
It took 1 year to get to n00b level. The next year is when things settle in. After 2 years, you'll have a solid foundation to keep honing your skills. You won't know everything, but you can hack together projects, & figure things out.
Also checkout Stackoverflow. Learning how to properly break down my problems into questions was a great exercise. It helped me understand what the real problem is vs what I thought it was.
Did you eventually start working as an engineer or was programming geared towards side projects and building Tindie? I did - my first job after learning how to code was as a developer advocate. Not 'coding' but putting what I learned to good use. That company was acquired, and I eventually became a web engineer at the company which acquired us. That was my last job before starting Tindie.
My local hackerspace, a 501(c)3, is just getting started. We're thinking of making some products to generate some funding... would Tindie be the right marketplace for us? Oh cool! Yep! We have members of hackspaces all over the globe on Tindie. Sounds like a perfect fit. If you have any questions, just pm me and we can help!
What sort of things did you do for market validation? Good question - the only market validation I did was ask the question on /Arduino. There wasn't a marketplace for this type of hardware (we are still the only "big" site doing what we are doing). The space is emerging now.
Did you have personal experience with this type of thing, people you knew who needed something like this, or some other type of research? You are right. The big question I got from investors is actually - 'How big is the market?' Unfortunately there isn't a good answer for that bc the market is growing / being defined now. Arduino/Raspberry Pi/Drones/3D printers are all just getting started and all growing like weeds. If those platforms become as big as we think they will, then a site like Tindie will have to emerge.
Also, how do you go about estimating market potential? The one thing we look at is the components market is a massive, multibillion dollar market. The type of components that are on Tindie, generally speaking, first come to market on Tindie. The market potential is entirely untapped. However having orders from gov't agencies & large businesses is very reassuring that there is a much greater opportunity than just hobbyists (which is what most people thing on first glance).
What's been your biggest challenge as CEO of your own start-up? Great questions -
What's the most frequent challenge you saw when working across various start-ups in the Valley? Biggest Challenge as CEO - Communication, balancing expectations, keeping everyone on the same page from users, employees to investors. You'll constantly hear, "Did you see X?" when someone thinks it is a competitor. Chances are it isn't and they have their own idea of what the business is which is different than your own.
What words of wisdom do you have for someone wanting to create their own start-up? Wisdom to start a startup - If it is a tech startup, one of your cofounders must be technical. Either yourself or your cofounder. If you can't build the first version/ a proof of concept yourself, start there. If you aren't technical, and don't know anyone technical, learn. In the valley you hear, "I'm looking for a techincal cofounder." so many times its crazy. You either already know someone (a good friend usually) or you don't. Trust me , you won't 'find' a techincal cofounder.
Thanks for your time (and sorry for all of the questions) No worries - these were excellent questions. Keep 'em coming!
You'd be shocked how many random emails I get with businesses proposals. Are these the recreate facebook type of deals where you do all the work and they get to be the owner for giving you the idea of facebook? It runs the gamut from sales, hiring, marketing, partnerships, you name it.
Did you have a good breakfast? Eh, coffee, leftovers, and IRC. We have a channel on Freenode I hop in every morning to check in with users (Tindarians) and make sure everything is right with the world.
(hash)tindie on Freenode ftw
You've mentioned a few times how you shouldn't outsource development to a third party. Can you elaborate on this? Why not? What was your experience? What should you do instead if you're a n00b coder (like myself)? Sure thing - if you hire a 3rd party, you will always have to pay someone else to iterate on the site. There is a 0% chance it will be right on the first shot. Therefore its really an invitation to spend a lot of money down the road - not just the upfront cost you are spending to get your idea made. This is what I did with Knowble - it cost something like $20k+. Please learn from my mistake :) You'll have to iterate, make changes, learn as you go. If you know how to code, then you can make those changes yourself. You'll do it in the morning/nights/weekends and it will only cost you your time.
What advice do you have for me as a student? Thank you, I think what you're doing is awesome! Very cool! Getting press / outside attention is very difficult (if you don't pay for PR - we don't pay for PR). Write blog posts, like to those sites. The link love will go a long way (over time). Most of the companies that you read about on TechCrunch, PandoDaily, etc are paying for PR which is why they get listed on all of those blogs and have stories come out at the same time (embargoes). As a student, build something! Just keep building things. You have some free time - take full advantage of it. Also meet your peers. Build a network of other students in your class. Some will go to Google, Twitter, the next Google, the next Twitter. Increase your chances of doing well by meeting as many super smart people as you can. Build projects with them. Just make things and learn from experience.
I'm also a CS student and for the longest time I've been interested in Arduino. How did you get started tinkering and where would you recommend someone such as myself begin so as to eventually purchase from your website? There are tons of beginner Arduino books. Arduino also has some great tutorials: Link to arduino.cc
In this age, if you have a CS background, Google is your friend :)
Did some more reading. I personally feel a lot of excitement for how well you're doing lol, congrats! What we're you doing before the 5 year run in the valley? How did you get started there? Learn to do the things you don't know yourself.
NEVER outsource development to a 3rd party company.
Learn how to code.
If you don't know how to code, don't bring on another person that doesn't know how to code.
So what compelled you to go from NC to CA? How did you start getting acquainted with people there? Joined Yelp. Yelp was maybe 40-50 people at that point. Flew myself for the interview, got the job, packed my car and hit the road.
As an aspiring entrepreneur myself, my question is this: what was the process like of getting the company from an idea to something you would be able to pitch to investors? The site was already live, we had products, orders, traffic. The sales early on were ~doubling month over month. Sure they were small but that seems like a very good sign. As it kept growing, people around me connected me with other people interested in the space. The first investor I got was someone that was in my network already, but I didn't know him. He also invests in early stage companies, understands marketplaces, and believes in the changes we are seeing in the hardware space. From introductory call to email saying, "I'd like to invest" was about 12 - 18 hours.
How did you fund the project initially? Spend time/money to get a VERY polished pitch deck.
How did you go about finding investors? If an investor says "stay in touch, I'm interested" thats a No.
Did you have to refine or iterate your idea at all in the process? We didn't have to iterate on the site, but I did iterate on the messaging/how I frame what we are doing depending upon the investor, and how that message was received by the last investor. I was constantly iterating what I said from pitch to pitch.
Would you feel that taking a year off to learn python was a worthwhile decision? With no coding background, can I learn it in a year? Definitely - 100% worthwile. I had saved up enough to live for a year without a paycheck (without healthcare...not smart but I did it). If you are interested, go for it. While you still have a job start learning HTML, CSS, some basic things. Give yourself some sort of foundation before taking the plunge. After a year won't be able to get a job as an engineer, but it will definitely help in the long run. I have never regretted that decision.
Any recommendations on resources to learn HTML and CSS? I have some programming skills (C, assembly, VHDL) and found the code academy stuff to be too slow and had a hard time seeing how to really apply it. Link to webdesign.tutsplus.com
I <3 Tuts / Envato.
How much did a year of free time cost you? Rent was $710 a month, Food ~$200-300. Add in taxes & other spending. $20k ish.
There are many exciting developments in hobby-level electronics development. First things like Arduino, now affordable ARM processors. In addition to cheap accelerometers, laser cutting for enclosures, 3d printing, etc. What trends and fads are you seeing that are exciting to you? What kind of products do you think we will see in Tindie next year? Five years from now? Ten? AirPi - Two 17yr olds in London built a shield for Raspberry Pi to turn it into a weather station. Brilliant, cheap product that I never saw coming and has done amazingly. They had to incorporate in the UK, take a loan from their parents, and just shipped hundreds of preorders they got on Tindie. The only thing I know for certain is we will have tens of thousands of hardware companies emerge over the next few years because it is becoming cheaper to prototype and easier to manufacture in lower volumes. Yes "hardware is hard" but it is getting easier and that only opens the door for more people to come in.
Tapster - a robot for manual app testing on mobile devices. EVERY mobile app developer in the world should have one bc of the time you'll save.
How did you come up with the name Tindie? Indie Tech...Tech Indie... Tindie.
The domain was available. Best $7 I've spent.
Amazing site! Just found it. Question/Suggestion ... I'm looking for a site that will accept commissions for one-off projects based on boards like Arduino or Raspberry. Any chance you're site will offer such a market? Thanks! Can you break down "will accept commissions?" Just want to make sure I fully understand what you are looking for.
Hi there. I have been looking into creating a website my self, and I was just curious as to how you build a user base for something like this? How did you get people to sell on Tindie when it first began? Good question - you'll need to figure out where your initial users are and tell them what you are doing. Get people in your corner. As you build the site, give them updates, let them sign up before the site is live. If you don't have enough users on day 1, do more to drive more users to the site. Launch only when you have some amount of users (few hundred or maybe a few thousand is the best case scenario). You'll never be ready to launch but definitely give yourself some momentum before opening the doors.
I did this by keeping everyone on /Arduino in the loop. As I found a name, a domain, logo, I'd share those updates. Sellers were able to sign up and "stock the shelves" prior to launch which meant once I opened the site for transactions, we had ~20 sellers/ products on the site and orders on day 1.
Have you considered reaching out to the Bitcoin mining community? Their hardware seems to fit into your site. We haven't but I'm 100% open to Bitcoin mining products on the site.
Have you considered accepting Bitcoin? We haven't due to its volatility.
Who is your favorite ninja turtle? Easy one - Michelangelo!
Do you plan on taking currencies like bitcoin, megacoin, etc? Not right now. Bitcoin is too volatile. From talking with other marketplaces that implemented Bitcoin, the % of transactions that come through are very, very small. Most people seem to be holding Bitcoins as an investment strategy (the gold analogy). I think that is true. At this point, we can get a much bigger bang for our engineering buck by working on other features vs implementing/maintaing Bitcoin or a similar digital currency.
Why did you decide to go to the valley for this? For someone thinking of starting an e-shop startup, what would you advise? I had been in SF for 4 years, then moved to Portland after the last company I was at was acquired. I moved back bc missed friends and our head of engineering is in Mountain View too. Made sense from a personal perspective.
Would I move to the valley if I didn't already have a connection to the area? I'm not sure. It is definitely cheaper to live somewhere else. However it is more difficult to get into the community from outside the area. If you live in the the valley, you'll constantly hear about startups/tech and meet people who are part of the scene. It's easier to be a part of the conversation if you are in the area.
I've heard from many of my friends in the industry that moving to SF is also a risk as many of the big companies pose a risk at hiring your engineers. Many of them end up moving their companies back to Canada where Engineers are much cheaper for the same quality. Very true. It is very common for people to stay at a job for one year, vest 25% of your options, and leave for the next hot startup. It is valuable to have a presence in the valley - but not necessary for your team to all be there. I'm a huge fan of distributed businesses.
So what's your take on the interest level in hardware overall? Do you think things being sold on the site will continue to increase in complexity? Or will they be limited in scope and cost in the future because people are more interested in the low end of things? Hey Chris! I think it will gain in complexity - esp as parts come down in price, and manufacturing lower quantities becomes more accessible. The opportunities only get magnified as those two trends accelerate.
I think we will always have low level / low end products, but the sky is the limit - in terms of price point and customers. We already have products that cost pennies to $1k+. We will begin to have more consumerish products - but I think those will fuel growth in hardware. The more interesting products emerge, the more interested people will jump into diy. Very cyclical. Arduino & Raspberry Pi just make that first step so much easier. Gateway hardware drugs.
This looks awesome, I'm surprised I've never heard of it. My question: how hard is it really to start your own business and what are some obstacles no one hears about? It is difficult but not impossible. Things to plan for: taxes & attorney fees. You'll want to set up your business correctly if you plan on raising outside investment. If you don't do that right up front, you'll get bit when you fundraise. The legal fees we'll have for this financing round will be over $10k I bet (probably more)
Any suggestions on where to find and learn how to do this hardware stuff? Where did you learn to it? Was there any doubt while creating this project? Did you think about giving up? Google is your best friend. There are books, tutorials, but just dive in. If you have some coding background just get started. Fortunately that is where I started so its more a process of picking something up and playing around (vs starting from 0).
Question: how much equity did you give up for the investment you've gained? Thanks! A this point it is just closing and collecting checks so the final % will be set in a few weeks once we have a definitive amount closed with this round. However the answer you are looking for is 20%-25%.
I have a question. What stage was Tindie in when you pitched to the investors? (users/revenue) What was is about Tindie that made them decide to invest? At this time last year, I forget where we were with users but we had $3600 in sales that month which would be about 100 orders. When talking to early stage investors, it is very much a gamble. The chance of failure much higher, but then again the opportunity is great. I haven't asked them point blank, but I think it ultimately boils down to they have an idea of how the world will work in the future, and you fit in that narrative.
I have a very refined idea for a web/mobile app start up. I have done months of research on the problem/solution I am building but I have no experience designing websites. Thus, I will need to pitch investors to fund development. What are any tips or resources to get in touch with potential investors? Unfortunately you need to get it built. With out a product & traction, it will be very tough sailing
Do you accept Bitcoin and if not can we expect it in the future? We don't right now and don't have any plans to in the future. Copying answer from another question "Bitcoin is too volatile. From talking with other marketplaces that implemented Bitcoin, the % of transactions that come through are very, very small. Most people seem to be holding Bitcoins as an investment strategy (the gold analogy). I think that is true. At this point, we can get a much bigger bang for our engineering buck by working on other features vs implementing/maintaing Bitcoin or a similar digital currency."
I'm an idea guy; I have new ideas everyday and am actually executing a few of them. My roadblock right now is getting it out there and selling it (to consumers, to investors). I have a new idea that, while the product is different than yours, could rope in every business sector. I've never built a business model; all of my stuff is from the idea point of view. I get an idea, find out if it's been done, and then make it work. What can I do to get the word out there and find investors? What kind of cut do you think is fair for investors? Build it. Unfortunately "ideas are cheap." You have to build it before anything else.
We are a startup who has built it (4+ years of work). Its a business administration product. We are in desperate need of sales and marketing department. How do we approach investors? If you are growing like a weed, they should be approaching you (at least some should). Based on the tone of your question, it sounds like that may not be the case?
As a maker who is currently in final stages of getting a product ready (ie 2nd round of PCB prototypes) any advice about how I go about getting it ready to sell on tindie? How do I determine a good initial batch size to order, handle shipping, refunds etc? Good question - once you are ready, you can list it as a Fundraiser (our version of crowfunding which really is just accepting preorders). It has to hit the min # of units sold to 'live' where we bill the orders and you fulfill those ordered. That will give you a good idea of the initial demand. Shipping & handling you'll need to do a little testing on your end bc it depends where you are located & the shipping service you select. Refunds we can handle on our end. You'll just need to tell us which orders to refund. If you have any other questions, feel free to email us at support(at) tindie.com. More than happy to help!
How did you get in front of 50 investors? Thanks for the AMA I kind of see now what I need to do for my Start Up getting rejected 10 times shouldn't be a big deal I guess. 100% from networking. Friend introducing me to someone else, who says you should talk to X. That person sends the intro, and then schedule a meeting. Cold emails don't get you very far with the top investors who are constantly being bombarded with pitches.
This is very interesting. How is the actual pitching process? I mean, once you get introduced, do you pitch to them in a Shark Tank style? over coffee/lunch? And which aspects of Tindie was the biggest seller to the investors? My background.
How did you come up with the idea.
Why now?
What are you doing?
Traction.
Future plans.
The team.
Some were more presentation style with a slideshow and just run through the deck where the investor most likely will interrupt you from time to time with questions on your points/assumptions.
0 were like Shark Tank.
I think the main thing we have going for us is our team -very strong with startup experience at well known companies/ great engineers. Next is our traction and position in the space.
Thanks for the answer! I thought you were a one man team before getting some funding. How did you get a team together when nothing was really proven? Ah at that point it was just myself and I had built everything up until that point. The site was live, we had products, orders, early traction.
of all congrats on the success with your start up and initial funding. What is the number one thing you would say investors look for in a start up? What helped you achieve success while pitching your ideas? Depends ultimately on the investor and if they are the lead or a follow on investor. The lead must believe in the space, have some idea of what is going, and therefore be passionate about the opportunity.
Follow on investors might know something about the space, might not. The one thing I didn't realize is how much they just "pile on." Most investors look for a signal by another big name investor, and if they are investing, looks good and they want in! The pile on mentality is alive and well.
So are you saying that funding is closed and you are not accepting any new investors? Right - the round is closed. The docs are written. The lead investors have already wired their funds. Now just emailing the smaller investors, getting signatures and the wires for their commitments.
1.) What was the toughest question you were asked during pitches? 2.) Any questions worth mentioning a company should be able to answer that they don't think about? 2) I don't think there is any particular question - just think ahead of what they will ask you. Have your questions down cold. Answer & then shut up. Don't be afraid of silence.
3.) Our products are similar in the sense of the needed co-creation so I'm interested in your marketing strategy on both fronts. (finding sellers and finding buyers) 3) Sellers & Customers has been word of mouth. We haven't don't much on the direct marketing side, so I don't have very good advice on that.
4.) I'm sure not everyone has been full time with the company, so how did you manage a team of 5 part-timers and making sure deadlines were met, goals accomplished, etc.? 1) Market size. There isn't a good answer. You can come up with many different answers with many different data points but at the end of the day, no one knows 4) Everyone is full -time.
I'm trying to convince some friends of mine to get serious about taking an idea of there's to an angel to see if they (we) could get funding. So my question is, what did you need to take to investors in the form of demos/research/etc. to get them to take you seriously enough to give you your first (and subsequent) rounds of funding? Build it first. If you get traction on the idea/project, investors will be interested. If it is just an idea, you'll have a very tough time. The only real answer - build it and they will come (if it is a great project and they see potential).
Makers / producers of open source hardware and products? What niche do you feel is currently not being addressed in the open source hardware arena? I think any hardware product today should have an open equivalent. The opportunity is just sitting there for someone to build an open version of X. Open source if a flywheel. Once you get it started and there is a community to support it, it only becomes stronger and better. At the end of the day, I don't see much difference btwn producer vs educator. If you have an open project, part of your job will be education. Just start working on something. At the end of the day, if you want to produce it and sell it you can. If not, no harm/no foul.
Hi Thank you for doing this. My question is, how hard it is to work with VC/Angel people? Do they push you really hard? Good question - some investors you won't get along with. You'll have different ideas/ look at the world differently/ it just isn't a fit. If that is the case, probably not a good fit as a major investor in your company. The can email you rather frequently - don't want to hate that part of your job...
I'm 19 and have no marketable skills beyond being the designated local tech geek. In terms of coding, I could mess around with the variables in JavaScript, but that's about it. Would I have any use in your organization? If not, what would you recommend the first thing I do to set down that path? Unfortunately not. Get more experienced & become a solid JS developer. Build projects, open the code, get feedback, critiqued by the JS community. You'll have a lot of value as a seasoned JS dev (esp as Node picks up traction)
I'd love to hear your thoughts on patents for DIY hardware! Let's say I've got a hardware design idea, but I know it's an evolution of existing technology. How do I go about researching conflicting patents that could prevent me from bringing my idea to market, what steps should I take to differentiate my idea from similar products, and at what point (if any) do I need to see an attorney? I'm anti-patent. It is a huge time/money suck and ultimately hinders innovation. I'm not the best person to ask on researching your design/idea/ etc but I'd probably just go ahead build it and go for it. Any time you spend looking for conflicting patents, someone else will launch their version and get a leg up.
Plans for the international market? Already international! We have customers in over 60 countries, sellers in over 40. I haven't looked lately but those were the numbers about a month or two ago.
Thank you for shipping to India! \o/
Hello Tindie. I am just now incorporating as of January 1st (LLC) with friends in the tech industry for our first start-up. They are all NASA employees and MIT grads with extensive tech background, but my background is in Public Policy and Regulations development. Are there tools on your website for new start ups in the tech field, or could you offer any recommendations as to navigating pitfalls for someone without extensive tech background? We can definitely do a better job on that end. Since you all have an engineering background, most likely the biggest problem will come in execution - sourcing manufacturers, parts, work abroad vs a domestic manufacturer. PM me and we can definitely help!
What has been your biggest regret starting Tindie? No regrets so far. It's been a huge learning experience- esp this year. If I were still at my old job, I'd have been constantly wondering whether or not this could take off. Happy I took the plunge.
HAve you ever thought to add Music Tech to the site? I know a lot of people who are into buying and creating their own midi controllers/instruments. OR have I overlooked something? We have it :) Link to www.tindie.com
How many register sellers and buyers do you have? Sellers: Over 300.
Last updated: 2013-12-06 11:10 UTC
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[Hiring] Java Callable Needed (XChange Library/Bitcoin Exchange API Work)

I have a trading program that I'm working on. I'm looking for someone to build a component of this program in the form of a Callable. The rest of the program uses the XChange library, so this component must be implemented with the XChange library as well.
The job of this component is to submit an an active limit order to a Bitcoin exchange via XChange. This order is intended to execute immediately and not sit on the order book. Interacting with a live financial market over the internet is a dicey proposition, so if things don't go to plan this component needs to deal with the things that can predictably go wrong.
An outline of how this component should work is below. Note terms in italics are meant to reference objects from the XChange library. These objects can be reviewed at XChange's Javadoc. I would reference you to the objects within the javadoc if I was able to, but alas that is not the case.
-The Callable has a constructor that passes to it a LimitOrder and Exchange. Don't worry about what those are or if they are set up properly, that is the responsibility of the wider program that you are working within. Use dummy LimitOrder and Exchange parameters during construction and testing of your component.
-Using a PollingTradeService created from the Exchange passed in via the constructor, attempt submission of the LimitOrder passed in via the constructor. I suggest keeping track of the orderID that is returned, you will probably need it later.
-Throw any exceptions you receive from the submission attempt at this stage back to the caller.
-If the submission attempt succeeds in reaching the exchange, wait X milliseconds before proceeding in your thread. X is a configurable variable that will be set to a range between 2000 and 10000 milliseconds. This period gives the exchange time to process the order, it also gives the market a brief period of time to react to this order. Throw an InterruptedException back to the caller if this waiting period is interrupted.
-After the waiting period is over, try to cancel the order via PollingTradeService's cancellation methods. If you encounter errors or exceptions, try to cancel it again at least three times before throwing errors back to the caller. It is important we try out best to cancel orders that didn't complete within our waiting period.
-It is now the responsibility of your component to report back to the caller what happened with the order. If it completed fully, calculate the weighted average of the price. If it completed partially, calculate the weighted average of the price, and also return how much did not complete. If it didn't complete at all, return something for that case as well. Feel free to use custom data types objects you create to assist you in this task.
-Test this component against the following live bitcoin exchanges (Bitstamp, BTC-e, Bitfinex).
-After the component passes testing, send me the text of your classes by whatever method you think is best, provided it is not going to put me at a security risk.
-Feel free to use any common libraries that will help you accomplish this task.
These instructions are not going to be perfect. Please ask questions about them publicly in this thread so other people with the same question can read my reply. If you have suggestions on how I can improve my communication, I welcome them.
If you are interested, submit to me an offer via PM for how much you would like to be paid to complete this project, and how long it will take you to complete. Also include a brief paragraph explaining relevant experience you have doing this kind of work. References to portfolio pieces or code in a repository you wrote are also important. Show me why you have the skills to build this.
I will be taking offers for the job over the next ~24 hours. If you get the job I will notify you at the end of this 24 hour period. Given the increase in scams lately I think it is best to do business via the escrow system I've done business with a number of people here on jobs4bitcoins and also bitcointalk.
submitted by wtfSurprise to Jobs4Bitcoins [link] [comments]

Curso JAVA #0 Instalacion JDK NetBeans Apache 2020 - YouTube Blockchain Technology Explained (2 Hour Course) - YouTube YouTube 58. Problem with mixing nextLine() and other Scanner class methods - Learn Java Subclassing the Account class

* < p >Instances of this class are not safe for use by multiple threads.</p> */ public class Transaction extends ChildMessage {/** * A comparator that can be used to sort transactions by their updateTime field. The ordering goes from most recent * into the past. */ public static final Comparator< Transaction > SORT_TX_BY_UPDATE_TIME = new ... Class Hierarchy. java.lang. Object org.bitcoinj.core. AbstractBlockChain. org.bitcoinj.core. BlockChain; org.bitcoinj.core. FullPrunedBlockChain; org.bitcoinj.core. public class Wallet extends BaseTaggableObject implements Serializable, BlockChainListener, PeerFilterProvider, KeyBag, TransactionBag. A Wallet stores keys and a record of transactions that send and receive value from those keys. Using these, it is able to create new transactions that spend the recorded transactions, and this is the fundamental operation of the Bitcoin protocol. To learn more ... For Java developers, BitCoinJ is an entry point to developing applications that interact with the Bitcoin network. In this final article in a three-part series, Dirk Merkel helps you set up ... Java Platform, Standard Edition (Java SE) helps you develop and deploy Java applications on desktops and servers. Java offers the rich user interface, performance, versatility, portability, and security that today's applications require.

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Curso JAVA #0 Instalacion JDK NetBeans Apache 2020 - YouTube

Learn Java Problem with mixing nextLine() and other Scanner class methods Download the Dr.Java Integrated Development Environment(IDE) - http://www.drjava.or... Enjoy the videos and music you love, upload original content, and share it all with friends, family, and the world on YouTube. Link to this course(special discount) https://www.udemy.com/course/how-to-create-generate-bitcoin-and-ethereum-crypto-addresses-offline/?ranMID=39197&ranEAID... Creating and using a simple BankAccount class in Java - Duration: 6:08. s1098451 64,826 views. 6:08. ... But how does bitcoin actually work? - Duration: 26:21. 3Blue1Brown Recommended for you. 26 ... Beginners Guide to Swing Trading Growth Stocks Class: https://theotrade.com/growth-stocks/ Sign up for the Trading VIX Options Course: https://theotrade.com/...

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