[ https://issues.apache.org/jira/browse/CASSANDRA-7039?page=com.atlassian.jira.plugin.system.issuetabpanels:all-tabpanel ]
Benedict updated CASSANDRA-7039: -------------------------------- Fix Version/s: 3.0 > DirectByteBuffer compatible LZ4 methods > --------------------------------------- > > Key: CASSANDRA-7039 > URL: https://issues.apache.org/jira/browse/CASSANDRA-7039 > Project: Cassandra > Issue Type: Improvement > Components: Core > Reporter: Benedict > Priority: Minor > Labels: performance > Fix For: 3.0 > > > As we move more things off-heap, it's becoming more and more essential to be > able to use DirectByteBuffer (or native pointers) in various places. > Unfortunately LZ4 doesn't currently support this operation, despite being JNI > based - this means we both have to perform unnecessary copies to de/compress > data from DBB, but also we can stall GC as any JNI method operating over a > java array using the GetPrimitiveArrayCritical enters a critical section that > prevents GC for its duration. This means STWs will be at least as long any > running compression/decompression (and no GC will happen until they complete, > so it's additive). > We should temporarily fork (and then resubmit upstream) jpountz-lz4 to > support operating over a native pointer, so that we can pass a DBB or a raw > pointer we have allocated ourselves. This will help improve performance when > flushing the new offheap memtables, as well as enable us to implement > CASSANDRA-6726 and finish CASSANDRA-4338. -- This message was sent by Atlassian JIRA (v6.2#6252)