* [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.
* CORDA-3762: Integration test exposing the problem reported
* CORDA-3726: Additional logging
* CORDA-3726: Prevent thread leaks
* CORDA-3726: New `journalBufferTimeout` parameter
* CORDA-3726: Override `journalBufferTimeout` parameter
* CORDA-3726: Making Detekt happier
* CORDA-3276: Account for extra thread user in MockNetwork
For real node this does not matter as `shutdown` can safely be called multiple times, which is not true for server thread provided by MockNetwork
* CORDA-3276: Do not make SMM shutdown "executor" as it belongs to AbstractNode
* CORDA-3276: Address input from @rick-r3
* CORDA-3276: Fix test after rebase
* CORDA-3701 Fix bugs in some iterator checkpoint serializers
* Added some more tests and tidied up implementation some more.
* Fix imports to be detekt compliant
* Add timeouts to tests
* adding blocked functions ro RestrictedEntityManager and creating RestrictedConnection class
* adding flow tests and fixing issues regarding the review
* adding quasar util to gradle
* updating flow tests
* adding space before } at .isThrownBy()
* adding spaces
the current code doesn't forward the exception to the logging system, this means that any cause inside the exception is lost as with all of the stacktraces (both the one of the thrown exception and the one belonging to its cause).
The correct way to log an exception is to pass both the message and the exception to the logging system.
