[ https://issues.apache.org/jira/browse/CASSANDRA-13632?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16170271#comment-16170271 ]
Andrew Whang commented on CASSANDRA-13632: ------------------------------------------ [~jasobrown] We're using old-school thrift via pycassa. I can repro in our shadow environment, but unable to in my dev using ccm + pycassa. Will let you know once I can get this error reproducible. > Digest mismatch if row is empty > ------------------------------- > > Key: CASSANDRA-13632 > URL: https://issues.apache.org/jira/browse/CASSANDRA-13632 > Project: Cassandra > Issue Type: Bug > Components: Local Write-Read Paths > Reporter: Andrew Whang > Assignee: Andrew Whang > Fix For: 3.0.x > > > This issue is similar to CASSANDRA-12090. Quorum read queries that include a > column selector (non-wildcard) result in digest mismatch when the row is > empty (key does not exist). It seems the data serialization path checks if > rowIterator.isEmpty() and if so ignores column names (by setting IS_EMPTY > flag). However, the digest serialization path does not perform this check and > includes column names. The digest comparison results in a mismatch. The > mismatch does not end up issuing a read repair mutation since the underlying > data is the same. > The mismatch on the read path ends up doubling our p99 read latency. We > discovered this issue while testing a 2.2.5 to 3.0.13 upgrade. > One thing to note is that we're using thrift, which ends up handling the > ColumnFilter differently than the CQL path. > As with CASSANDRA-12090, fixing the digest seems sensible. -- This message was sent by Atlassian JIRA (v6.4.14#64029) --------------------------------------------------------------------- To unsubscribe, e-mail: commits-unsubscr...@cassandra.apache.org For additional commands, e-mail: commits-h...@cassandra.apache.org