Added command-line option: `--pause-all-flows` to the Node to control this.
This mode causes all checkpoints to be set to status PAUSED when the
state machine starts up (in StartMode.Safe mode).
Changed the state machine so that PAUSED checkpoints are loaded into
memory (the checkpoint is deserialised but the flow state is left serialised)
but not started.
Messages from peers are queued whilst the flow is paused and processed
once the flow is resumed.
* Adding value needed for the rapid deployment of Azure UAT enviroments
* Parameterizing Rpc user
* Removing duplicate config requirement
* Forcing users to provide sshPort for node config generation with docker image
The new flow sleep made `NotaryWhitelistTests` flaky which highlighted
an issue with the change to how a flow sleeps. Messages were being
pumped while the flow was sleeping which lead to inconsistent behaviour.
Messages are no longer pumped while a flow sleeps.
* CORDA-3715: When loading cordapps now check that contract classes have class version between 49 and 52
* CORDA-3715: Now check class version when contract verification takes place.
* CORDA-3715: Making detekt happy with number of levels in func
* CORDA-3715: Make use of new ClassGraph release which provides class file major version number.
* CORDA-3715: Changed package name in test jars
* CORDA-3715: Use ClassGraph when loading attachments.
* CORDA-3715: Reverted file to 4.5 version
* CORDA-3715: Updating method to match non deterministic version.
* CORDA-3715: Added in default param.
* CORDA-3715: Adjusted min JDK version to 1.1
* CORDA-3715: Switching check to JDK 1.2
* CORDA-3715: Now version check SerializationWhitelist classes.
* CORDA-3715: Switched default to null for range.
* [EG-438] First commit of error code interface
* [EG-438] Implement error reporter and a few error codes
* [EG-438] Add unit tests and default properties files
* [EG-438] Add the error table builder
* [EG-438] Update initial properties files
* [EG-438] Add some Irish tests and the build.gradle
* [EG-438] Fall back for aliases and use different resource strategy
* [EG-438] Define the URL using a project-specific context
* [EG-438] Tidy up initialization code
* [EG-438] Add testing to generator and tidy up
* [EG-438] Remove direct dependency on core and add own logging config
* [EG-438] Fix compiler warnings and tidy up logging
* [EG-438] Fix detekt warnings
* [EG-438] Improve error messages
* [EG-438] Address first set of review comments
* [EG-438] Use enums and a builder for the reporter
* [EG-438] Address first set of review comments
* [EG-438] Use enums and a builder for the reporter
* [EG-438] Add kdocs for error resource static methods
* [EG-440] Add error code for duplicate CorDapp loading
* [EG-438] Handle enums defined with underscores
* [EG-440] Add errors for some CorDapp loading scenarios
* [EG-440] Finish adding errors for CorDapp loading
* [EG-440] Fix up errors in properties files
* [EG-440] Start change to error code definition
* [EG-440] Update error code definition and add resource generation tool
* [EG-440] Tidy up error resource generation tool frontend
* [EG-440] Small refactorings and add kdocs
* [EG-440] Generate all missing resources
* [EG-440] Some refactoring and start writing a test
* [EG-440] Update unit test for resource generator
* [EG-440] Renaming of various parts of the error tool
* [EG-440] Add testing for errors and fix an issue in resource generation
* [EG-440] Add a kdoc for context provider API
* [EG-440] Remove old code from repository
* [EG-440] Address some review comments
* CORDA-3291 `isKilled` flag and session errors for killed flows
## Summary
Two major improvements have been worked on:
- A new flag named `isKilled` has been added to `FlowLogic` to allow
developers to break out of loops without suspension points.
- Killed flows now send session errors to their counter parties allowing
their flows to also terminate without further coordination.
Achieving these changes required a __fundamental__ change to how flows are
killed as well as how they sleep.
## `isKilled` flag
The addition of `FlowLogic.isKilled` allows flows to check if the
current flow has been killed. They can then throw an exception to lead
to the flow's termination (following the standard error pathway). They
can also perform some extra logic or not throw an exception if they
really wanted to.
No matter what, once the flag is set, the flow will terminate. Due to
timing, a killed flow might successfully process its next suspension
event, but it will then process a killed transition and terminate.
## Send session errors when killing a flow
A flow will now send session errors to all of its counter parties. They
are transferred as `UnexpectedFlowEndException`s. This allows initiated
flows to handle these errors as they see fit, although they should
probably just terminate.
## How flows are killed
### Before
Originally we were relying on Quasar to interrupt a flow's fiber, we
could then handle the resulting `InterruptedException`. The problem with
this solution is that it only worked when a flow was already suspended
or when a flow moved into suspension. Flows stuck in loops did not work.
### After
We now *do not* use Quasar to interrupt a flow's fiber. Instead, we
switch `FlowStateMachine.isKilled` to true and schedule a new event.
Any event that is processed after switching this flag will now cause a
`KilledFlowTransition`. This transition follows similar logic to how
error propagation works. Note, the extra event allows a suspended flow
to be killed without waiting for the event that it was _really_ waiting
for.
This allows a lot of the tidy up code in `StateMachineManager.killFlow`
to be removed as tidy up is executed as part of removing a flow.
Deleting a flow's checkpoint and releasing related soft locks is still
handled manually in case of infinite loops but also triggered as part
of the actions executed in a transition.
This required flow sleeping to be changed as we no longer rely on
quasar.
## How flows now sleep
The reliance on Quasar to make a flow sleep has been removed.
Instead, when a flow sleeps we create a `ScheduledFuture` that is
delayed for the requested sleep duration. When the future executes it
schedules a `WakeUpFromSleep` event that wakes up the flow... Duh.
`FlowSleepScheduler` handles the future logic. It also uses the same
scheduled thread pool that timed flows uses.
A future field was added to `StateMachineState`. This removes the
need for concurrency control around flow sleeps as the code path does
not need to touch any concurrent data structures.
To achieve this:
- `StateMachineState.future` added as a `var`
- When the `ScheduledFuture` is created to wake up the flow the passed
in `StateMachineState` has its `future` value changed
- When resumed `future` and `isWaitingForFuture` are set to `null` and
`false` respectively
- When cancelling a sleeping flow, the `future` is cancelled and nulled
out. `isWaitingForFuture` is not changed since the flow is ending anyway
so really the value of the field is not important.
* [EG-438] First commit of error code interface
* [EG-438] Implement error reporter and a few error codes
* [EG-438] Add unit tests and default properties files
* [EG-438] Add the error table builder
* [EG-438] Update initial properties files
* [EG-438] Add some Irish tests and the build.gradle
* [EG-438] Fall back for aliases and use different resource strategy
* [EG-438] Define the URL using a project-specific context
* [EG-438] Tidy up initialization code
* [EG-438] Add testing to generator and tidy up
* [EG-438] Remove direct dependency on core and add own logging config
* [EG-438] Fix compiler warnings and tidy up logging
* [EG-438] Fix detekt warnings
* [EG-438] Improve error messages
* [EG-438] Address first set of review comments
* [EG-438] Use enums and a builder for the reporter
* [EG-438] Add kdocs for error resource static methods
* [EG-438] Handle enums defined with underscores
* [EG-438] Slight refactoring of startup code
* [EG-438] Port changes to error reporting code from future branch
* [EG-438] Also port test changes
* [EG-438] Suppress a deliberately unused parameter
* CORDA-3722 withEntityManager can rollback its session
## Summary
Improve the handling of database transactions when using
`withEntityManager` inside a flow.
Extra changes have been included to improve the safety and
correctness of Corda around handling database transactions.
This focuses on allowing flows to catch errors that occur inside an
entity manager and handle them accordingly.
Errors can be caught in two places:
- Inside `withEntityManager`
- Outside `withEntityManager`
Further changes have been included to ensure that transactions are
rolled back correctly.
## Catching errors inside `withEntityManager`
Errors caught inside `withEntityManager` require the flow to manually
`flush` the current session (the entity manager's individual session).
By manually flushing the session, a `try-catch` block can be placed
around the `flush` call, allowing possible exceptions to be caught.
Once an error is thrown from a call to `flush`, it is no longer possible
to use the same entity manager to trigger any database operations. The
only possible option is to rollback the changes from that session.
The flow can continue executing updates within the same session but they
will never be committed. What happens in this situation should be handled
by the flow. Explicitly restricting the scenario requires a lot of effort
and code. Instead, we should rely on the developer to control complex
workflows.
To continue updating the database after an error like this occurs, a new
`withEntityManager` block should be used (after catching the previous
error).
## Catching errors outside `withEntityManager`
Exceptions can be caught around `withEntityManager` blocks. This allows
errors to be handled in the same way as stated above, except the need to
manually `flush` the session is removed. `withEntityManager` will
automatically `flush` a session if it has not been marked for rollback
due to an earlier error.
A `try-catch` can then be placed around the whole of the
`withEntityManager` block, allowing the error to be caught while not
committing any changes to the underlying database transaction.
## Savepoints / Transactionality
To make `withEntityManager` blocks work like mini database transactions,
save points have been utilised. A new savepoint is created when opening
a `withEntityManager` block (along with a new session). It is then used
as a reference point to rollback to if the session errors and needs to
roll back. The savepoint is then released (independently from
completing successfully or failing).
Using save points means, that either all the statements inside the
entity manager are executed, or none of them are.
## Some implementation details
- A new session is created every time an entity manager is requested,
but this does not replace the flow's main underlying database session.
- `CordaPersistence.transaction` can now determine whether it needs
to execute its extra error handling code. This is needed to allow errors
escape `withEntityManager` blocks while allowing some of our exception
handling around subscribers (in `NodeVaultService`) to continue to work.
On node start, load CordaServices before starting the NotaryService,
so that the NotaryService can check that the services it requires are
available when starting.
Resolves#6172.
* Retired the rst doc source structure under /docs and updated the /docs/README.md
*Rollback of /example-code and /whitepaper dirs back under /docs dir until new code example process is in place
