I did some experiments to understand our full GC issues better last night. Here are the results: http://people.apache.org/~todd/hbase-fragmentation/
<http://people.apache.org/~todd/hbase-fragmentation/>Basically my conclusion here is that (for these YCSB workloads) the memstore is way worse for heap fragmentation than the block cache. Also we now have some tools and reference for comparison if we make any changes to memstore to try to combat this issue. -Todd -- Todd Lipcon Software Engineer, Cloudera
