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Vijay edited comment on CASSANDRA-4860 at 5/7/13 9:45 PM: ---------------------------------------------------------- {quote} Providing a couple of tests which show the broken byte buffer. {quote} No it is not broken, MeasureDeep was omitting the shared buffer size... which is kind of wrong... try the following. {quote} {code} ByteBuffer bb = ByteBuffer.allocate(1000); long objectSize = ObjectSizes.getSize(bb); MemoryMeter meter2 = new MemoryMeter(); long meterSize = meter2.measureDeep(bb); Assert.assertEquals(meterSize, objectSize); {code} {quote} Here's the KeyKacheKey relevant parts {quote} Agreed! Looks like error is from CLHC, i am still not sure where its broken MappedFileDataInput.readBytes copies anyways.... [~tjake]? was (Author: vijay2...@yahoo.com): {quote} Providing a couple of tests which show the broken byte buffer. {quote} Yeah MeasureDeep was omitting the shared buffer size... which is kind of wrong... try the following. {quote} {code} ByteBuffer bb = ByteBuffer.allocate(1000); long objectSize = ObjectSizes.getSize(bb); MemoryMeter meter2 = new MemoryMeter(); long meterSize = meter2.measureDeep(bb); Assert.assertEquals(meterSize, objectSize); {code} {quote} Here's the KeyKacheKey relevant parts {quote} Agreed! Looks like error is from CLHC, i am still not sure where its broken MappedFileDataInput.readBytes copies anyways.... [~tjake]? > Estimated Row Cache Entry size incorrect (always 24?) > ----------------------------------------------------- > > Key: CASSANDRA-4860 > URL: https://issues.apache.org/jira/browse/CASSANDRA-4860 > Project: Cassandra > Issue Type: Bug > Components: Core > Affects Versions: 1.1.0, 1.2.3, 2.0 > Reporter: Chris Burroughs > Assignee: Vijay > Fix For: 1.2.0 beta 3 > > Attachments: 0001-4860-v2.patch, 0001-4860-v3.patch, > 0001-CASSANDRA-4860-for-11.patch, 0001-CASSANDRA-4860.patch, > 4860-perf-test.zip, 4860-tests.patch, trunk-4860-revert.patch > > > After running for several hours the RowCacheSize was suspicious low (ie 70 > something MB) I used CASSANDRA-4859 to measure the size and number of > entries on a node: > In [3]: 1560504./65021 > Out[3]: 24.0 > In [4]: 2149464./89561 > Out[4]: 24.0 > In [6]: 7216096./300785 > Out[6]: 23.990877204647838 > That's RowCacheSize/RowCacheNumEntires . Just to prove I don't have crazy > small rows the mean size of the row *keys* in the saved cache is 67 and > Compacted row mean size: 355. No jamm errors in the log > Config notes: > row_cache_provider: ConcurrentLinkedHashCacheProvider > row_cache_size_in_mb: 2048 > Version info: > * C*: 1.1.6 > * centos 2.6.32-220.13.1.el6.x86_64 > * java 6u31 Java HotSpot(TM) 64-Bit Server VM (build 20.6-b01, mixed mode) -- This message is automatically generated by JIRA. If you think it was sent incorrectly, please contact your JIRA administrators For more information on JIRA, see: http://www.atlassian.com/software/jira