[CASSANDRA-13292] Replace MessagingService usage of MD5 with something more modern

• Type: Improvement
• Status: Open
• Priority: Normal
• Resolution: Unresolved
• Component/s: Legacy/Core
• Assignee: Michael Kjellman
• Reporter: Michael Kjellman

Authors

Michael Kjellman

• Created: 02/Mar/17 22:18
• Updated: 15/May/19 09:10

Description

While profiling C* via multiple profilers, I've consistently seen a significant amount of time being spent calculating MD5 digests.

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

Pending CASSANDRA-13291, it would be pretty easy to:

1. 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
2. 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.

Issue Links

• is blocked by: CASSANDRA-13291 Replace usages of MessageDigest with Guava's Hasher
• is related to: CASSANDRA-14611 Quorum reads of wide partitions are expensive due to inefficient hashing in AbstractCell