Propagate trickle_fsync settings to compressed SSTable writers#4927
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samueldlightfoot wants to merge 1 commit into
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Propagate trickle_fsync settings to compressed SSTable writers#4927samueldlightfoot wants to merge 1 commit into
samueldlightfoot wants to merge 1 commit into
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CompressedSequentialWriter rebuilt its SequentialWriterOption but copied only bufferSize/bufferType/finishOnClose, dropping trickleFsync and trickleFsyncByteInterval. Compression is the default, so trickle_fsync had no effect on SSTable data files: SequentialWriter.doFlush never reached the interval sync. Carry the two fields through the rebuild. Add tests asserting the full option-rebuild contract (caller knobs pass through, buffer sizing follows the compression layout) and that the interval sync actually fires while writing compressed data.
netudima
reviewed
Jul 13, 2026
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| @Test | ||
| public void testTrickleFsyncFiresWhileWritingCompressedData() throws IOException |
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nit: should we split the test to 2? (also to not share collector: it is not an issue now but if it is changed the test may start to fail)
netudima
reviewed
Jul 13, 2026
| try (CountingCSW writer = new CountingCSW(off, offOffsets, null, disabled, | ||
| CompressionParams.lz4(chunk), collector)) | ||
| { | ||
| writer.write(new byte[chunk * 20]); |
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nit: a comment would be nice to clarify that trickleFsyncByteInterval is applied before compression.. (it is probably even worth to mention in configuration file, it can be confusing)
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How hard would be to adjust the logic and apply trickleFsyncByteInterval for lower disk writing level, after compression?
netudima
approved these changes
Jul 13, 2026
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CompressedSequentialWriter rebuilt its SequentialWriterOption but copied only bufferSize/bufferType/finishOnClose, dropping trickleFsync and trickleFsyncByteInterval. Compression is the default, so trickle_fsync had no effect on SSTable data files: SequentialWriter.doFlush never reached the interval sync. Carry the two fields through the rebuild.
Add tests asserting the full option-rebuild contract (caller knobs pass through, buffer sizing follows the compression layout) and that the interval sync actually fires while writing compressed data.
https://issues.apache.org/jira/browse/CASSANDRA-21487
patch by Sam Lightfoot; reviewed by for CASSANDRA-21487