Right, I meant 4GB heap vs. the standard 1GB. And all other options in cassandra.in.sh at their defaults.
Sorry I am a bit new to JVM tuning, and very new to Cassandra :) -- Ilya On Tue, Apr 6, 2010 at 12:16 AM, Benjamin Black <b...@b3k.us> wrote: > I am specifically suggesting you NOT use a heap that large with your > 8GB machines. Please test with 4GB first. > > On Tue, Apr 6, 2010 at 12:13 AM, Ilya Maykov <ivmay...@gmail.com> wrote: >> That does sound similar. It's possible that the difference I'm seeing >> between ConsistencyLevel.ZERO and ConsistencyLevel.ALL is simply due >> to the fact that using ALL slows down the writers enough that the GC >> can keep up. I could do a test with multiple clients writing at ALL in >> parallel tomorrow. If there are still no problems writing at ALL even >> with extra load from additional clients, that might point to problems >> in how async writes are handled vs. sync writes. >> >> I will also do some profiling of the server processes with both ZERO >> and ALL writer behaviors and report back. >> >> RE: JVM_OPTS, I will try running with the "more sane" options (but a >> larger heap) as well. >> >> -- Ilya >> >> On Mon, Apr 5, 2010 at 11:59 PM, Rob Coli <rc...@digg.com> wrote: >>> On 4/5/10 11:48 PM, Ilya Maykov wrote: >>>> >>>> No, the disks on all nodes have about 750GB free space. Also as >>>> mentioned in my follow-up email, writing with ConsistencyLevel.ALL >>>> makes the slowdowns / crashes go away. >>> >>> I am not sure if the above is consistent with the cause of #896, but the >>> other symptoms ("I inserted a bunch of data really fast via Thrift and GC >>> melted my machine!") sound like it.. >>> >>> https://issues.apache.org/jira/browse/CASSANDRA-896 >>> >>> =Rob >>> >> >