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Posted to commits@cassandra.apache.org by "Jon Haddad (JIRA)" <ji...@apache.org> on 2019/04/23 00:38:00 UTC

[jira] [Commented] (CASSANDRA-13292) Replace MessagingService usage of MD5 with something more modern

    [ https://issues.apache.org/jira/browse/CASSANDRA-13292?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=16823594#comment-16823594 ] 

Jon Haddad commented on CASSANDRA-13292:
----------------------------------------

I was recently doing some testing on 3.11.4 to see the impact of using huge partitions, and noticed digest calculations are taking up over 50% of cpu time.

Icicle graph attached.

 [^quorum-concurrency-reads-quorum.svg] 

> Replace MessagingService usage of MD5 with something more modern
> ----------------------------------------------------------------
>
>                 Key: CASSANDRA-13292
>                 URL: https://issues.apache.org/jira/browse/CASSANDRA-13292
>             Project: Cassandra
>          Issue Type: Improvement
>          Components: Legacy/Core
>            Reporter: Michael Kjellman
>            Assignee: Michael Kjellman
>            Priority: Normal
>         Attachments: quorum-concurrency-reads-quorum.svg
>
>
> While profiling C* via multiple profilers, I've consistently seen a significant amount of time being spent calculating MD5 digests.
> {code}
> Stack Trace	Sample Count	Percentage(%)
> sun.security.provider.MD5.implCompress(byte[], int)	264	1.566
>    sun.security.provider.DigestBase.implCompressMultiBlock(byte[], int, int)	200	1.187
>       sun.security.provider.DigestBase.engineUpdate(byte[], int, int)	200	1.187
>          java.security.MessageDigestSpi.engineUpdate(ByteBuffer)	200	1.187
>             java.security.MessageDigest$Delegate.engineUpdate(ByteBuffer)	200	1.187
>                java.security.MessageDigest.update(ByteBuffer)	200	1.187
>                   org.apache.cassandra.db.Column.updateDigest(MessageDigest)	193	1.145
>                      org.apache.cassandra.db.ColumnFamily.updateDigest(MessageDigest)	193	1.145
>                         org.apache.cassandra.db.ColumnFamily.digest(ColumnFamily)	193	1.145
>                            org.apache.cassandra.service.RowDigestResolver.resolve()	106	0.629
>                               org.apache.cassandra.service.RowDigestResolver.resolve()	106	0.629
>                                  org.apache.cassandra.service.ReadCallback.get()	88	0.522
>                                     org.apache.cassandra.service.AbstractReadExecutor.get()	88	0.522
>                                        org.apache.cassandra.service.StorageProxy.fetchRows(List, ConsistencyLevel)	88	0.522
>                                           org.apache.cassandra.service.StorageProxy.read(List, ConsistencyLevel)	88	0.522
>                                              org.apache.cassandra.service.pager.SliceQueryPager.queryNextPage(int, ConsistencyLevel, boolean)	88	0.522
>                                                 org.apache.cassandra.service.pager.AbstractQueryPager.fetchPage(int)	88	0.522
>                                                    org.apache.cassandra.service.pager.SliceQueryPager.fetchPage(int)	88	0.522
>                                                       org.apache.cassandra.cql3.statements.SelectStatement.execute(QueryState, QueryOptions)	88	0.522
>                                                          org.apache.cassandra.cql3.statements.SelectStatement.execute(QueryState, QueryOptions)	88	0.522
>                                                             org.apache.cassandra.cql3.QueryProcessor.processStatement(CQLStatement, QueryState, QueryOptions)	88	0.522
>                                                                org.apache.cassandra.cql3.QueryProcessor.process(String, QueryState, QueryOptions)	88	0.522
>                                                                   org.apache.cassandra.transport.messages.QueryMessage.execute(QueryState)	88	0.522
>                                                                      org.apache.cassandra.transport.Message$Dispatcher.messageReceived(ChannelHandlerContext, MessageEvent)	88	0.522
>                                                                         org.jboss.netty.channel.SimpleChannelUpstreamHandler.handleUpstream(ChannelHandlerContext, ChannelEvent)	88	0.522
>                                                                            org.jboss.netty.channel.DefaultChannelPipeline.sendUpstream(DefaultChannelPipeline$DefaultChannelHandlerContext, ChannelEvent)	88	0.522
>                                                                               org.jboss.netty.channel.DefaultChannelPipeline$DefaultChannelHandlerContext.sendUpstream(ChannelEvent)	88	0.522
>                                                                                  org.jboss.netty.handler.execution.ChannelUpstreamEventRunnable.doRun()	88	0.522
>                                                                                     org.jboss.netty.handler.execution.ChannelEventRunnable.run()	88	0.522
>                                                                                        java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor$Worker)	88	0.522
>                                                                                           java.util.concurrent.ThreadPoolExecutor$Worker.run()	88	0.522
>                                                                                              java.lang.Thread.run()	88	0.522
> {code}
> Pending CASSANDRA-13291, it would be pretty easy to:
> # Switch out the hashing implementation from MD5 to implementations such as adler128 and murmur3_128 (but certainly not limited to) and do some profiling to compare the net improvement on latencies and CPU usage
> # As we can't switch the algorithm from MD5 without breaking things, we could rev the MessagingService protocol version -- like we already do for things like switching from Snappy compression -> LZ4, we could switch to the new hashing implementation once all peers in the node are upgraded and support the new MessagingService version.



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