[CASSANDRA-3286] Performance issue in ByteBufferUtil

• Type: Improvement
• Status: Resolved
• Priority: Low
• Resolution: Fixed
• Fix Version/s: 1.0.1
• Assignee: T Jake Luciani Assign to me
• Reporter: T Jake Luciani

Authors

T Jake Luciani

Reviewers

Jonathan Ellis

• Created: 30/Sep/11 16:52
• Updated: 16/Apr/19 09:32
• Resolved: 30/Sep/11 18:20

Description

Profiling 1.0 we can see ByteBufferUtil.compareUnsigned is slow.

Excl. Incl. Incl. Incl. Name 
User CPU User CPU Sync Wait Sync Wait 
sec. sec. sec. Count 
318.491 318.491 1.400 113786 <Total> 
40.561 40.561 0. 0 <Unknown> 
18.972 19.093 0. 0 <static>@0xd949 (<libpthread-2.5.so>) 
17.718 18.730 0. 0 sun.security.provider.MD5.implCompress(byte[], int) 
14.396 14.396 0. 0 __pthread_cond_signal 
8.908 8.908 0. 0 org.apache.cassandra.utils.ByteBufferUtil.compareUnsigned(java.nio.ByteBuffer, java.nio.ByteBuffer) 
7.435 7.688 0. 0 __pthread_cond_timedwait 
7.127 7.182 0. 0 <static>@0xd8c9 (<libpthread-2.5.so>) 
7.072 7.072 0. 0 jbyte_disjoint_arraycopy 
6.764 39.065 0. 0 org.apache.cassandra.utils.ReducingIterator.computeNext() 
6.533 17.575 0. 0 java.util.concurrent.ConcurrentSkipListMap.doPut(java.lang.Object, java.lang.Object, boolean) 
6.346 6.346 0. 0 com.sun.crypto.provider.SunJCE_c.a(byte[], int, byte[], int) 
5.378 5.433 0. 0 send 
4.861 6.643 0.000 1 org.apache.cassandra.utils.ByteBufferUtil.read(java.io.DataInput, int) 
4.410 9.260 0. 0 org.apache.commons.collections.iterators.CollatingIterator.least() 
4.355 4.355 0. 0 java.io.ByteArrayOutputStream.write(int) 
4.300 6.632 0. 0 java.io.ByteArrayOutputStream.write(byte[], int, int) 
3.827 30.190 0. 0 org.apache.cassandra.dht.RandomPartitioner.decorateKey(java.nio.ByteBuffer) 
3.783 23.954 0. 0 org.apache.cassandra.utils.FBUtilities.hash(java.nio.ByteBuffer[]) 
3.783 3.860 0. 0 <static>@0xd486c (<libc-2.5.so>) 
3.739 3.739 0. 0 clock_gettime

We can avoid the problem when the ByteBuffer has a backing array