Dan Newton c2fd8253ea
CORDA-3777 Reload after every checkpoint (#6494)
Enable reloading of a flow after every checkpoint is saved. This
includes reloading the checkpoint from the database and recreating the
fiber.

When a flow and its `StateMachineState` is created it checks the node's
config to see if the `reloadCheckpointAfterSuspend` is set to true. If it is
it initialises `StateMachineState.reloadCheckpointAfterSuspendCount`
with the value 0. Otherwise, it remains `null`.

This count represents how many times the flow has reloaded from its
checkpoint (not the same as retrying). It is incremented every time the
flow is reloaded.

When a flow suspends, it processes the suspend event like usual, but
it will now also check if `reloadCheckpointAfterSuspendCount` is not
`null` (that it is activated) and process a 
`ReloadFlowFromCheckpointAfterSuspend`event, if and only if 
`reloadCheckpointAfterSuspendCount` is greater than
`CheckpointState.numberOfSuspends`.

This means idempotent flows can reload from the start and not reload
again until reaching a new suspension point.

Flows that skip checkpoints can reload from a previously saved
checkpoint (or from the initial checkpoint) and will continue reloading
on reaching the next new suspension point (not the suspension point that
it skipped saving).

If the flow fails to deserialize the checkpoint from the database upon
reloading a `ReloadFlowFromCheckpointException` is throw. This causes
the flow to be kept for observation.
2020-07-28 16:27:51 +01:00
2020-07-09 15:34:34 +01:00
2020-04-09 15:31:19 +01:00

Corda

License

Corda

Corda is an open source blockchain project, designed for business from the start. Only Corda allows you to build interoperable blockchain networks that transact in strict privacy. Corda's smart contract technology allows businesses to transact directly, with value.

Features

  • Smart contracts that can be written in Java and other JVM languages
  • Flow framework to manage communication and negotiation between participants
  • Peer-to-peer network of nodes
  • "Notary" infrastructure to validate uniqueness and sequencing of transactions without global broadcast
  • Enables the development and deployment of distributed apps called CorDapps
  • Written in Kotlin, targeting the JVM

Getting started

  1. Read the Getting Started documentation
  2. Run the Example CorDapp
  3. Read about Corda's Key Concepts
  4. Follow the Hello, World! tutorial

Contributing

Corda is an open-source project and contributions are welcome!

To find out how to contribute, please see our contributing docs.

License

Apache 2.0

Acknowledgements

YourKit

YourKit supports open source projects with its full-featured Java Profiler.

YourKit, LLC is the creator of YourKit Java Profiler and YourKit .NET Profiler, innovative and intelligent tools for profiling Java and .NET applications.

Description
Corda is an open source blockchain project, designed for business from the start. Only Corda allows you to build interoperable blockchain networks that transact in strict privacy. Corda's smart contract technology allows businesses to transact directly, with value.
Readme Pixar 354 MiB
Languages
Kotlin 94.3%
Java 2.5%
C++ 2.1%
Python 0.3%
Shell 0.3%
Other 0.3%