Raising maxlogs to 64 would give you improvement. Cheers
On Dec 26, 2013, at 8:35 PM, Norbert Burger <[email protected]> wrote: > 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 >>
