We are not seeing any balancer related logs btw anymore...
On Mon, Jan 27, 2014 at 8:23 PM, Ted Yu <[email protected]> wrote: > Looking at the changes since release 0.94.7, I found: > > HBASE-8655 Backport to 94 - HBASE-8346(Prefetching .META. rows in case only > when useCache is set to true) > HBASE-8698 potential thread creation in MetaScanner.metaScan > > If possible, can you upgrade your cluster ? > > Cheers > > > On Mon, Jan 27, 2014 at 8:02 PM, Ted Yu <[email protected]> wrote: > > > Do you see the following (from > > HConnectionManager$HConnectionImplementation#locateRegionInMeta) ? > > > > if (LOG.isDebugEnabled()) { > > LOG.debug("locateRegionInMeta parentTable=" + > > Bytes.toString(parentTable) + ", metaLocation=" + > > ((metaLocation == null)? "null": "{" + metaLocation + > "}") > > + > > ", attempt=" + tries + " of " + > > this.numRetries + " failed; retrying after sleep of " + > > > > > > On Mon, Jan 27, 2014 at 7:51 PM, Varun Sharma <[email protected]> > wrote: > > > >> Actually not sometimes but we are always seeing a large # of .META. > reads > >> every 5 minutes. > >> > >> > >> On Mon, Jan 27, 2014 at 7:47 PM, Varun Sharma <[email protected]> > >> wrote: > >> > >> > The default one with 0.94.7... - I dont see any of those logs. Also we > >> > turned off the balancer switch - but looks like sometimes we still > see a > >> > large number of requests to .META. table every 5 minutes. > >> > > >> > Varun > >> > > >> > > >> > On Mon, Jan 27, 2014 at 7:37 PM, Ted Yu <[email protected]> wrote: > >> > > >> >> In HMaster#balance(), we have (same for 0.94 and 0.96): > >> >> > >> >> for (RegionPlan plan: plans) { > >> >> LOG.info("balance " + plan); > >> >> > >> >> Do you see such log in master log ? > >> >> > >> >> > >> >> On Mon, Jan 27, 2014 at 7:26 PM, Varun Sharma <[email protected]> > >> >> wrote: > >> >> > >> >> > We are seeing one other issue with high read latency (p99 etc.) on > >> one > >> >> of > >> >> > our read heavy hbase clusters which is correlated with the balancer > >> >> runs - > >> >> > every 5 minutes. > >> >> > > >> >> > If there is no balancing to do, does the balancer only scan the > table > >> >> every > >> >> > 5 minutes - does it do anything on top of that if the regions are > >> >> balanced > >> >> > ? > >> >> > > >> >> > Varun > >> >> > > >> >> > >> > > >> > > >> > > > > >
