[CC4] CNDB-15558: ULID-based SSTable ID generation can fail with an NPE #2175
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running CI, and checking if there's a unit test to add here… |
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Thanks for the PR! Overall, LGTM and I appreciate the increased test coverage. I left a few minor nits inline. Can you run CNDB CI with a build of this PR?
test/unit/org/apache/cassandra/io/sstable/ULIDBasedSSTableIdGeneratorTest.java
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ULID-based SSTable ID generation can fail with an NPE when generating a new ID. The root cause is that the underlying ULID generator can generate an empty Optional when the clock is moved backwards to before the previously generated ID or in certain rare overflow conditions when timestamp collides. If it's our first time through the generation loop, we prematurely exit with a null newVal. Top of the error stack: ``` java.lang.NullPointerException at org.apache.cassandra.utils.TimeUUID.approximateFromULID(TimeUUID.java:58) at org.apache.cassandra.io.sstable.ULIDBasedSSTableId.<init>(ULIDBasedSSTableId.java:52) at org.apache.cassandra.io.sstable.ULIDBasedSSTableId$Builder.lambda$generator$0(ULIDBasedSSTableId.java:129) ``` This can cause a flush to fail. Continue looping until newVal gets a value. The loop can spin until the corrected time catches up to the time of the most recently used ULID generation ID. This should be a short duration in a healthy cluster without large time corrections from sync. Tests are added in ULIDBasedSSTableIdGeneratorTest A package-protected constructor is introduced for ULIDBasedSSTableIdGeneratorTest.testGeneratorRetryOnEmptyOptional() Cassandra Applicability: upstream doesn't have ULIDBasedSSTableId (and won't because CASSANDRA-17048).
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cndb tests: https://github.com/riptano/cndb/pull/16340 |
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❌ Build ds-cassandra-pr-gate/PR-2175 rejected by Butler3 regressions found Found 3 new test failures
Found 1 known test failures |
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https://github.com/riptano/cndb/issues/15558
What is the issue
ULID-based SSTable ID generation can fail with an NPE when generating a new ID. The root cause is that the underlying ULID generator can generate an empty Optional when the clock is moved backwards to before the previously generated ID or in certain rare overflow conditions when timestamp collides. If it's our first time through the generation loop, we prematurely exit with a null newVal.
Top of the error stack:
This can cause a flush to fail.
What does this PR fix and why was it fixed
Continue looping until newVal gets a value. The loop can spin until the corrected time catches up to the time of the most recently used ULID generation ID. This should be a short duration in a healthy cluster without large time corrections from sync.