0280299104
Fix broken IssuerFlowTest Fix IssuerFlowTests after rebase. Resolve conflicts after rebase. Soft locking converted to use persistent store. Added additional optional 'includeLockStates' parameter in VaultService states API call. Added Vault softLocked states query API call. Fixed commercial paper failing test. Improved exception handling on soft locking UPDATE statement. Using SELECT FOR UPDATE to ensure correct soft locking data visibility. Db query operations moved out of mutex code (as locking managed by underlying DB) Adjusted logging severity levels. Adjusted logging severity levels. GenerateSpending now performing fine grained query for unconsumed states by joining with contract_cash_states table. Using H2 proprietary cummulative counting feature (using sessioni SET variables) Refactored and simplified HibernateObserver constructor to enable usage in JUnit tests. Event generator issues larger random amounts (10,000..1,000,000) to those than are spent (0..10,000) Adjusted Issue (5:1) and Exit (10:1) generation frequency vs spending. Minor fixes: added optional lockid into select for spending criteria, set notary, additional trace logging. Generate Cash Schema by default upon node start-up (as part of NodeSchemaService initialisation). Explicitly close JDBC statements in finally() blocks. Tightened HibernateObserver constructor. Fix CommercialPaper test (was missing auto-generation of CONTRACT_CASH table) Revert default JVM size back to 200Mb. Revert default number of iterations in Explorer Node Simulation mode (back to 10000 with .5 sec sleep interval). Remove redundant setter function. Added TODO messages indicating Requery / H2 restrictions & caveats. Consumed states lock updates now performed in general consumed state Update. Updated/added Soft Locking documentation. Addressed initial PR comments: use THREAD_LOCAL_KRYO, use AbstractParty, extract helper method, improve readability, address some doc typos Addressed PR comment: removed lockId from WireTransaction. Fixed soft locking UPDATE statements. Improvements to VaultSoftLockManager for auto-registration of soft locks for flows with spendable states (as notifications from vault). Other optimisations (IssuerFlow no longer explicitly reserve/release issued state) and improvements (soft lock release management of soft locks, docs update) Performance update: now using Requery for UPDATE in release soft locking (non-composite key statement) Removed redundant TODO messages (TODO: revisit Kryo bug when using THREAD_LOCAL_KYRO) Minor fixes following rebase Fixed failing JUnit following rebase Addressed MH PR review items (1st pass) Fix broken JUnit Significant changes to RDBMS operations within coin selection and soft locking as requested by PR review. (Removed SELECT FOR UPDATE; added RETRY upon coin selection; reverting partial soft locks) Addressed a number of PR review requests added by MH (comments/spelling, lockID instantiation, HibernateObserver instantiation, cash schema white-listing usage) Addressed latest PR review comments from RP. Minor fixes following rebase from master. Fixed final failing JUnit (issuer flow concurrent). Updated TraderDemo to trigger concurrent issuance of cash. Fixed compiler warning on lockId null check. Fixed subtle bug in coin selection intermittently surfaced in IntegrationTestTutorial. Fixed small memory leak. Removed stray } in logger trace message. Slight rewording of description of Soft Locking in docs. Renamed NoStatesAvailableException to StatesNotAvailableException. generateSpend is now Suspendable (calls sleep method on flow upon coin selection retry). Added companion function to enable a Strand to sleep but without locking transactional context. Improved logging, changed to StateNotAvailableException, using Flow sleep upon retry, tweaked SELECT criteria in coin selection, fixed bug when insufficient states selectable, generateSpend is now @suspendable Improved handling and logging of flow results in Simulation Mode. Fixed minor error in sleep when not an active flow. Retry coin selection when unavailable states (as these may become available as new states). Additional debug logging to highlight and identify H2 coin selection sporadic bug. Inlined sleep method due to intermittent Quasar error. Re-introduce selection clause that prevents selection and temporary locking of already locked states (by other flows). Improved trace logging for coin selection (SQL row level info). Correctly calling FlowStateMachineImpl sleep (now inlined and working correctly) Fixed rebase error. Remove redundant TODO message.
Corda
Corda is a decentralised database system in which nodes trust each other as little as possible.
Features
- A P2P network of nodes
- Smart contracts
- Flow framework
- "Notary" infrastructure to validate uniqueness of transactions
- Written as a platform for distributed apps called CorDapps
- Written in Kotlin, targeting the JVM
Read our full and planned feature list here.
Getting started
Firstly, read the Getting started documentation.
Next, use the following guides to set up your dev environment:
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If you are on Windows use this getting started guide which also explains through how to run the sample apps.
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Alternatively if you are on Mac/Linux, watch this brief Webinar which walks through getting Corda, installing it, building it, running nodes and opening projects in IntelliJ.
After the above, watching the following webinars will give you a great introduction to Corda:
Webinar 1 – Introduction to Corda
Richard Brown, R3 Chief Technology Officer, explains Corda's unique architecture, the only distributed ledger platform designed by and for the financial industry's unique requirements. You may want to read the Corda non-technical whitepaper as pre-reading for this session.
Webinar 2 – Corda Developers’ Tutorial
Roger Willis, R3 Developer Relations Lead, provides an overview of Corda from a developer’s perspective and guidance on how to start building CorDapps. You may want to view Webinar 1 - Introduction to Corda as preparation for this session. NB. This was recorded for the M5 release.
Building on Corda
To build your own CorDapps:
- Clone the CorDapp Template repository
- Read the README (IMPORTANT!)
- Read the Writing a CorDapp documentation
To look at the Corda source and run some sample applications:
- Clone this repository
- To run some sample CorDapps, read the running the demos documentation
- Start hacking and contribute!
Useful links
Development State
Corda is currently in very early development and should not be used in production systems. Breaking changes will happen on minor versions until 1.0. Experimentation with Corda is recommended.
Pull requests, experiments, and contributions are encouraged and welcomed.
Background
The project is supported by R3, a financial industry consortium, which is why it contains some code for financial use cases and why the documentation focuses on finance. The goal is to use it to construct a global ledger, simplifying finance and reducing the overheads of banking. But it is run as an open source project and the basic technology of a peer-to-peer decentralised database may be useful for many different projects.
Contributing
Please read here.
License
Acknowledgements
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