No sir. I am seeing general out of heap space messages, nothing about direct buffers. One specific example would be while Thrift is writing to a ByteArrayOutputStream to send off scan results. (I can get an exact stack trace - easily :} - if it would be helpful.) It seems as if there just isn't enough heap left, after controlling for what I have so far.
As a clarification of my original email: each row has 100 cells, and each cell has a 100 MB value. So, one row would occupy just over 10 GB. On Tue, May 27, 2014 at 4:49 PM, <[email protected]> wrote: > Are you seeing something similar to the error in > https://issues.apache.org/jira/browse/ACCUMULO-2495? > > ----- Original Message ----- > > From: "Bill Havanki" <[email protected]> > To: "Accumulo Dev List" <[email protected]> > Sent: Tuesday, May 27, 2014 4:30:59 PM > Subject: Supporting large values > > I'm trying to run a stress test where each row in a table has 100 cells, > each with a value of 100 MB of random data. (This is using Bill Slacum's > memory stress test tool). Despite fiddling with the cluster configuration, > I always run out of tablet server heap space before too long. > > Here are the configurations I've tried so far, with valuable guidance from > Busbey and madrob: > > - native maps are enabled, tserver.memory.maps.max = 8G > - table.compaction.minor.logs.threshold = 8 > - tserver.walog.max.size = 1G > - Tablet server has 4G heap (-Xmx4g) > - table is pre-split into 8 tablets (split points 0x20, 0x40, 0x60, ...), 5 > tablet servers are available > - tserver.cache.data.size = 256M > - tserver.cache.index.size = 40M (keys are small - 4 bytes - in this test) > - table.scan.max.memory = 256M > - tserver.readahead.concurrent.max = 4 (default is 16) > > It's often hard to tell where the OOM error comes from, but I have seen it > frequently coming from Thrift as it is writing out scan results. > > Does anyone have any good conventions for supporting large values? > (Warning: I'll want to work on large keys (and tiny values) next! :) ) > > Thanks very much > Bill > > -- > // Bill Havanki > // Solutions Architect, Cloudera Govt Solutions > // 443.686.9283 > > -- // Bill Havanki // Solutions Architect, Cloudera Govt Solutions // 443.686.9283
