Hi Shahab, Ted talked about 0.94. In 0.98 there is no (known) issues with the on-line merge.
JM 2014-08-28 14:33 GMT-04:00 Shahab Yunus <[email protected]>: > I have a question here. In 0.98 the merge_region command which can be run > through HBase shell is not reliable? If we simply want to merge 2 regions > at a time? I thought that the older Merge tool was not safe. > > Thanks, > Shahab > > > On Thu, Aug 28, 2014 at 2:26 PM, Bryan Beaudreault < > [email protected] > > wrote: > > > I've done it. This is the code I used: > > https://gist.github.com/bbeaudreault/7567385 > > > > It comes from the hbase source, but is modified to actually work (the > class > > provided in hbase is private and does not work out of the box). There is > a > > readme at the bottom of the gist with my process. One important note > > though, I did this with a deep understanding (after hours of reading > hbase > > code and doing tests on a test cluster) of how it all works. And even > then > > I felt nervous to do it in prod. Hence why I went the snapshot/compact > > route. > > > > I would definitely test it on a test cluster and get some familiarity > > before getting close to a production table. That said, I've run this on > > 8-10 production tables a few months ago, reducing in size from 10-20x in > > some cases. > > > > > > On Thu, Aug 28, 2014 at 2:19 PM, Ted Tuttle <[email protected]> > wrote: > > > > > Hello- > > > > > > We recently realized our region size is 1G and need to increase it to > get > > > our region count under control. I've done some research on merging > > regions > > > and have come away confused. > > > > > > There is the ops handbook: > > > > > > http://hbase.apache.org/book/ops.regionmgt.html > > > > > > And then there is this horror story: > > > > > > http://metabroadcast.com/blog/so-you-broke-hbase > > > > > > Is there someone out there that has done a large scale (i.e. 10:1 > > > reduction on 10k's of regions) merge successfully on HBase 0.94? If > so, > > > how did you do it? > > > > > > Thanks, > > > Ted > > > > > > > > >
