Document ProcessingScheduleService.runAtFixedRate

[korthout]

Description

The ProcessingScheduleService has a runAtFixedRate which is implemented in a simple way: run the task after a delay and then schedule itself. But there are some quirks around this that should be clear to the caller.

Specifically, that there is an initial delay before the task is run, and that due to the way it reschedules the task, time traveling only affects the currently scheduled delay.

Related issues

related to #10064

Definition of Done

Not all items need to be done depending on the issue and the pull request.

Code changes:

• The changes are backwards compatibility with previous versions
• If it fixes a bug then PRs are created to backport the fix to the last two minor versions. You can trigger a backport by assigning labels (e.g. backport stable/1.3) to the PR, in case that fails you need to create backports manually.

Testing:

• There are unit/integration tests that verify all acceptance criterias of the issue
• New tests are written to ensure backwards compatibility with further versions
• The behavior is tested manually
• The change has been verified by a QA run
• The impact of the changes is verified by a benchmark

Documentation:

• The documentation is updated (e.g. BPMN reference, configuration, examples, get-started guides, etc.)
• New content is added to the release announcement
• If the PR changes how BPMN processes are validated (e.g. support new BPMN element) then the Camunda modeling team should be informed to adjust the BPMN linting.

Please refer to our review guidelines.

[github-actions]

Test Results

   843 files  ±  0     843 suites  ±0   1h 37m 59s ⏱️ -50s
6 442 tests +76  6 431 ✔️ +76  11 💤 ±0  0 ❌ ±0 
6 626 runs  +76  6 615 ✔️ +76  11 💤 ±0  0 ❌ ±0 

Results for commit 5182043. ± Comparison against base commit e1a5ee9.

♻️ This comment has been updated with latest results.

[pihme]

bors merge

[zeebe-bors-camunda]

Build succeeded:

• Go linting
• Java checks
• Test summary