Thanks Ted and Liang. I do see the "Too may hlogs" line in our logs.
We're using the default values for hbase.regionserver.maxlogs = 32 and hbase.regionserver.hlog.blocksize = 64MB, so So given a heapsize = 12GB and lowerLimit = 0.35, does it make sense that I should raise maxlogs to be something like 64 or 72? Norbert On Thu, Dec 26, 2013 at 11:03 PM, Ted Yu <[email protected]> wrote: > Norbert: > What's your setting for hbase.regionserver.maxlogs ? > > Cheers > > On Dec 26, 2013, at 7:51 PM, 谢良 <[email protected]> wrote: > > > Do you observe some log like "Too many hlogs" before flushing a few > > dozen KB log ? Just want to double-check it's weather a forcing flush > issue > > or not:) > > > > Thanks, > > Liang > > ________________________________________ > > 发件人: Norbert Burger [[email protected]] > > 发送时间: 2013年12月27日 5:52 > > 收件人: [email protected] > > 主题: one table flushes at much smaller sizes than other? > > > > Hi folks, we're currently running CDH4.1.2 (HBase 0.92 + patches). > > > > Looking through the logs, I'm seeing that some tables are flushing at > much > > lower size than others (a few dozen KB as opposed to the expected 128 > MB). > > > > Looking through some of great case studies like [1], [2], and [3], it's > not > > clear to me why this is happening. We're using the defaults for upper, > > lower limits (0.35 and 0.40, respectively), and the RS status pages show > > that we're only using 25% of our memstore allocation. > > > > Our regions/RS ratio is currently at 60-70. We do have some other tables > > online where column families are skewed heavily sizewise -- could this be > > causing other tables in our cluster to flush more frequently than others? > > > > Norbert > > > > [1] > http://blog.sematext.com/2012/07/16/hbase-memstore-what-you-should-know/ > > [2] http://www.ngdata.com/visualizing-hbase-flushes-and-compactions/ > > [3] http://gbif.blogspot.com/2012/07/optimizing-writes-in-hbase.html >
