[GitHub] [lucene] uschindler commented on a change in pull request #203: LUCENE-10019: Align file starts in CFS files to have proper alignment (8 bytes)

[GitBox <gi...@apache.org>]

uschindler commented on a change in pull request #203:
URL: https://github.com/apache/lucene/pull/203#discussion_r663210271



##########
File path: lucene/core/src/test/org/apache/lucene/index/TestSizeBoundedForceMerge.java
##########
@@ -45,6 +45,8 @@ private static IndexWriterConfig newWriterConfig() {
     IndexWriterConfig conf = newIndexWriterConfig(null);
     conf.setMaxBufferedDocs(IndexWriterConfig.DISABLE_AUTO_FLUSH);
     conf.setRAMBufferSizeMB(IndexWriterConfig.DEFAULT_RAM_BUFFER_SIZE_MB);
+    // don't use compound files, because the overhead make size checks unreliable.
+    conf.setUseCompoundFile(false);

Review comment:
       It looks like this test is VEEEEERY sensitive to file size. As CFS files have some overhead, the test sometimes breaks, especially if the CFS setting is not consistent.
   
   The problem in this is test is very small index sizes, so using the size of smallest segment as upper limit for the maximum segment size break. I don't know why, but it looks like a CFS file with alignment is too much overhead so rounding in merge policy breaks and it assumes CFS files as too large.
   
   @mikemccand: do you have an idea why this test sometimes break with CFS files. @jpountz already fixed this test a few years ago, but to me this looks like too many assumprions on sizes of files that can't hold true. So easiest is to disable CFS files, as the sizes are then consistent.




-- 
This is an automated message from the Apache Git Service.
To respond to the message, please log on to GitHub and use the
URL above to go to the specific comment.

To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org

For queries about this service, please contact Infrastructure at:
users@infra.apache.org



---------------------------------------------------------------------
To unsubscribe, e-mail: issues-unsubscribe@lucene.apache.org
For additional commands, e-mail: issues-help@lucene.apache.org