jihoonson opened a new pull request #11189:
URL: https://github.com/apache/druid/pull/11189
### Description
Most internal APIs used in Druid's ingestion should be idempotent to handle
transient errors. This PR fixes the idempotence of two APIs used in native
batch ingestion.
The first API is the segment allocation API used in dynamic partitioning.
Currently, transient network errors or task failures can lead to non-contiguous
segment partitionIds allocated by this API. This can be a problem because
`PartitionHolder` of those segments of non-contiguous partitionIds will be
never complete in the broker timeline. As a result, everything will look fine,
that means, the task will succeed, segments will be published into the metadata
store, historicals will load and announce them, but you will never be able to
query them.
To fix the segment allocation API, I had to add a new API that accepts extra
parameters such as `sequenceName` to guarantee the idempotence. This will break
the rolling upgrade that replaces nodes with a newer version one at a time. To
resolve this issue, I added a new taskContext,
`useLineageBasedSegmentAllocation`, to control which protocol to use for
segment allocation in dynamic partitioning. This context is true by default and
must be set to false during rolling upgrade. The in-place rolling upgrade is
not a consideration because batch ingestion doesn't support it.
The second API is the task report API used in all native batch ingestion
types. This API can handle retries triggered by transient network errors, but
cannot handle duplicate reports by task retries. As a result, if there is a
task that failed after sending its report, the supervisor task will count both
the report of the failed task and that of the retry task. Because of this bug,
the parallel task can incorrectly estimate the cardinality of partition column
and the distribution of partition column in hash and range partitioning,
respectively.
Finally, to test the fix, I added random task failures and API call retries
(emulating transient network failures) in
`AbstractParallelIndexSupervisorTaskTest`. All unit tests extending this class,
such as `CompactionTaskParallelRunTest`,
`HashPartitionMultiPhaseParallelIndexingTest`,
`SinglePhaseParallelIndexingTest`, and
`RangePartitionMultiPhaseParallelIndexingTest`, now run with potential
transient task failures and API call retries.
<hr>
##### Key changed/added classes in this PR
* `SinglePhaseParallelIndexTaskRunner`
* `TaskMonitor`
* `AbstractParallelIndexSupervisorTaskTest`
<hr>
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- [ ] added integration tests.
- [ ] been tested in a test Druid cluster.
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