Hi Christopher, Just to ensure I'm looking at the correct property, by "in-memory map size per tserver" are you referring to the property *tserver.memory.maps.max* in *accumulo-site.xml*? If that's the case, I'm using 1GB for that property.
I am running loggers on each tserver. Is the default that Accumulo writes to at least two loggers? I see config item * logger.recovery.file.replication* is set to 2 (by default); is that what controls this? Digging around, I also see that logger.archive.replication is set to 2, and logger.archive is false. What does logger.archive and logger.archive.replication do? I find no mention of "archive" in the User Manual. Many thanks Christopher, your help is always appreciated. On Wed, Oct 23, 2013 at 2:10 PM, Christopher <[email protected]> wrote: > The data in the write-ahead logs is needed until the tserver flushes > the in memory maps to disk. Assuming you have a logger running on > every tserver, and tservers write to at least two loggers, you should > ensure that the size of the disk area is *at least* two times as big > as your in-memory map size per tserver. I'd say 5x-10x the in-memory > map size is probably safe. So, if your tservers are running with 2GB > of memory, then a 10-20GB area is probably more than sufficient. > > -- > Christopher L Tubbs II > http://gravatar.com/ctubbsii > > > On Wed, Oct 23, 2013 at 1:02 PM, Terry P. <[email protected]> wrote: > > Greetings all, > > For Accumulo 1.4 where write ahead logs are not yet stored in HDFS, does > > anyone have guidancewith respect to sizing the walog area? What exactly > > triggers when write ahead logs get removed? What might cause them to > hang > > around for an extended period of time (as in under abnormal > circumstances)? > > > > The system this applies to will see an ingest rate of approximately 2000 > > docs per second averaging 1-2K each (broken out into 12 columns each, so > > 24,000 entries per second) across 6 tabletserver nodes. > > > > Thanks in advance, > > Terry >
