How about forcing a region split and moving the splits to RSs with less load ?
On Fri, Nov 15, 2013 at 7:21 AM, Jia Wang <ra...@appannie.com> wrote: > Then the case is simple, as i said "check your row key design, you can find > the start and end row key for each region, from which you can know why your > request with a specific row key doesn't hit a specified region" > > Cheers > Ramon > > > On Thu, Nov 14, 2013 at 8:47 PM, Asaf Mesika <asaf.mes...@gmail.com> > wrote: > > > It's from the same table. > > The thing is that some <customerId> simply have less data saved in HBase, > > while others have x50 (max) data. > > I'm trying to check how people designed their rowkey around it, or had > > other out-of-the-box solution for it. > > > > > > > > On Thu, Nov 14, 2013 at 12:06 PM, Jia Wang <ra...@appannie.com> wrote: > > > > > Hi > > > > > > Are the regions from the same table? If it was, check your row key > > design, > > > you can find the start and end row key for each region, from which you > > can > > > know why your request with a specific row key doesn't hit a specified > > > region. > > > > > > If the regions are for different table, you may consider to combine > some > > > cold regions for some tables. > > > > > > Thanks > > > Ramon > > > > > > > > > On Thu, Nov 14, 2013 at 4:59 PM, Asaf Mesika <asaf.mes...@gmail.com> > > > wrote: > > > > > > > Hi, > > > > > > > > Have anyone ran into a case where a Region Server is hosting regions, > > in > > > > which some regions are getting lots of write requests, and the rest > > gets > > > > maye 1/1000 of the rate of write requests? > > > > > > > > This leads to a situation where the HLog queue reaches its maxlogs > > limit > > > > since, those HLogs containing the puts from slow-write regions are > > > "stuck" > > > > until the region will flush. Since those regions barely make it to > > their > > > > 256MB flush limit (our configuration), they won't flush. The HLogs > > queue > > > > gets bigger due to the fast-write regions, until reaches the stress > > mode > > > of > > > > "We have too many logs". > > > > This in turn flushes out lots of regions, many of them (about 100) > are > > > > ultra small (10k - 3mb). After 3 rounds like this, the compaction > queue > > > > gets very big....in the end the region server drops dead, and this > load > > > > somehow is moved to another RS, ... > > > > > > > > We are running 0.94.7 with 30 RS. > > > > > > > > I was wondering how did people handled a mix of slow-write-rate and > > > > high-write-rate of regions in 1 RS? I was thinking of writing a > > customer > > > > load balancer, which keeps tabs on the write request count and > memstore > > > > size, and move all the slow-write regions to 20% of cluster RS > > dedicated > > > to > > > > slow regions, thus releasing the fast write regions to work freely. > > > > > > > > Since this issue is hammering our production, we're about to try to > > > > shut-down the WAL, and risk losing some information in those > slow-write > > > > regions until we can come up with a better solution. > > > > > > > > Any advice would be highly appreciated. > > > > > > > > Oh - our rowkey is quite normal: > > > > <customerId><bucket><Timestamp><uniqueId> > > > > > > > > Thanks! > > > > > > > > > > -- Bharath Vissapragada <http://www.cloudera.com>
