External Tasks are Sorted By Creation Date - Backend & Java Client

[psavidis]

Acceptance Criteria (Required on creation)

• [x] Add the capability of sorting by createTime to the Query API

• [x] Adjust Persistence Layer to Sort by Create Time

  • [x] Make sure the Queries that retrieves External Tasks & apply the Sorting Logic consider the new parameter for ASC & DESC orders. We don’t implement logic that brings null values into a specific order. We let the database vendor decide how it is handled.
  • [x] Adjust the queries: selectExternalTasksForTopics & selectExternalTaskByQueryCriteria for Fetch & Lock API & Query API Respectively.
  • [x] MyBatis Adjustments: ExternalTaskEntity, Interface, Insert Query, ResultMap & columnSelection (see ExternalTask.xml)
  • [x] Add Unit Test that guarantees the new Sorting Behaviour for different Db profiles.

• [x] Add Sort by Create Time to Fetch and Lock API

  • [x] Add the parameter to the Fetch and Lock API of External Tasks

  • [x] Currently usePriority implementation defines the order statically to DESC. Change this to so that ordering can work both for ASC and DESC configuration for prioritising create-time in LIFO and FIFO orders.

  • [x] Implement Multi-Level Sorting By Considering Fields in the following order:

    • [x] First priority is taken into account
    • [x] In the equality scenario, create time will be used next.
    • [x] The above order should be preserved for the Fetch and Lock API
    • [x] For the External Task Query API, the multi-level sorting is handled consistently with all other Query APIs via the #orderBy… fluent builder pattern.

• [x] Add Create Time to Open API

• [x] Add the Sort by Create Time Capability to the Java Client

  • [x] Expose the new parameter and fetch and lock Sorting options to the Java client
  • [x] When useCreateTime is set to true and no Sorting Direction is specified (null value), DESC will be used as a sensible default
  • [x] When useCreateTime and usePriority are both enabled, the Sorting should take place by:
  • [x] First by applying priority DESC
  • [x] On priority equality, the selected createTime direction should be used

Hints

Links

Breakdown

### Pull Requests
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3897
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3912
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3919
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/3918
- [ ] https://github.com/camunda/camunda-bpm-platform/pull/4009/

[mboskamp]

@psavidis, this ticket is in progress but assigned to me. What is the status?

[psavidis]

@psavidis, this ticket is in progress but assigned to me. What is the status?

I've corrected the status to Review. The changes are applied for all the Code Review points. We can review them further.

[mboskamp]

I have reviewed the engine and engine-rest changes. Let's discuss those before I move on to dependent PRs.

[psavidis]

The Code review of the backend is done and can proceed. Also the client points have been addressed too.

The spring boot client integration can be part of the client since the changes are not numerous.

[psavidis]

Update for the Review :

For the Spring-Boot integration of the Client, the following agreements have been made with the tech lead:

• When useCreateTime & orderByCreateTime have been configured via Spring Boot configuration, it makes sense to fail with an exception (SpringExternalTaskClientException)
• When the user configures a value that is neither asc or desc, the client will throw an SpringExternalTaskClientException.