Thanks for the response. Yes that makes sense, and it is the answer I expected, but needed to make sure from guys here.
I understand in theory having thousands of scanners are expected to improve performance. Has this been done in practice, or is your statement purely for explanation purposes? Given a single query (or nested query), how can I split up the work per scanner? What other methodologies can I use to improve from a single point on-demand query time? Jonathan Gray-2 wrote: > > Adding additional regionservers does not directly impact scan > performance if there is no other load. A region only lives on a single > server so scanning a region is limited to the speed of that server. > > The more servers the have, the more nodes you distribute your dataset > over. > > A single scanner in isolation will run approximately the same on a small > cluster vs a large cluster. But if you have thousands of scanners > swamping a cluster of 10 machines vs 100 machines, you expect ~10x > speedup with 10x the nodes. Of course that is a simplification but the > goal of a system like HBase is to scale linearly with the number of nodes. > > Make sense? > > JG > > llpind wrote: >> Is there a relation between # of regionservers to performance of >> scanners? >> >> Say I have 6 boxes and I up to 12, will I see much improvement? >> >> >> Jonathan Gray-2 wrote: >>> Depends on the use case. >>> >>> Generally most clusters colocate DataNodes and RegionServers, so an >>> equal number. >>> >>> >>> llpind wrote: >>>> Okay looks like it worked that way. >>>> >>>> Thanks. >>>> >>>> What is recommended? datanodes to regionservers? Is it best to have >>>> equal >>>> # or diff? >>>> >>>> >>>> >>>> Jonathan Gray-2 wrote: >>>>> You do not need to restart the system to add or remove regionservers >>>>> (or >>>>> hdfs datanodes). >>>>> >>>>> You should update your files, yes. But to add a new regionserver, set >>>>> up all of the configuration files like the other nodes, and then start >>>>> it up: >>>>> >>>>> $HBASE_HOME/bin/hbase-daemon.sh start regionserver >>>>> >>>>> >>>>> Without seeing what was happening prior to the Scanner expiration in >>>>> the >>>>> regionserver logs, it's hard to tell what the problem is. Can you >>>>> post >>>>> the full logs somewhere? >>>>> >>>>> JG >>>>> >>>>> llpind wrote: >>>>>> Hey Guys, >>>>>> >>>>>> What do I need to do to add regionservers? I thought all I had to do >>>>>> was >>>>>> modify the regionservers file. I've added another box, and updated >>>>>> the >>>>>> regionservers file (and Hadoop slaves), restarted hadoop/hbase >>>>>> cluster, >>>>>> and >>>>>> receive the following when trying to access data via scanner: >>>>>> >>>>>> 09/07/02 09:10:02 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 0 time(s). >>>>>> 09/07/02 09:10:03 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 1 time(s). >>>>>> 09/07/02 09:10:04 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 2 time(s). >>>>>> 09/07/02 09:10:05 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 3 time(s). >>>>>> 09/07/02 09:10:06 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 4 time(s). >>>>>> 09/07/02 09:10:07 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 5 time(s). >>>>>> 09/07/02 09:10:08 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 6 time(s). >>>>>> 09/07/02 09:10:09 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 7 time(s). >>>>>> 09/07/02 09:10:10 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 8 time(s). >>>>>> 09/07/02 09:10:11 INFO ipc.HBaseClient: Retrying connect to server: >>>>>> /192.168.0.222:60020. Already tried 9 time(s). >>>>>> 09/07/02 09:10:11 INFO ipc.HbaseRPC: Server at /192.168.0.222:60020 >>>>>> not >>>>>> available yet, Zzzzz... >>>>>> >>>>>> >>>>>> on the box: ======================================================= >>>>>> >>>>>> 2009-07-02 08:59:59,265 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 2646315558964059972 lease expired >>>>>> 2009-07-02 08:59:59,272 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 1810370986171440259 lease expired >>>>>> 2009-07-02 08:59:59,273 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -4857942742243144770 lease expired >>>>>> 2009-07-02 08:59:59,288 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 3123162276497438016 lease expired >>>>>> 2009-07-02 08:59:59,289 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 608738648389654018 lease expired >>>>>> 2009-07-02 08:59:59,296 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -2521940152150106398 lease expired >>>>>> 2009-07-02 08:59:59,297 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 8091669741182809260 lease expired >>>>>> 2009-07-02 08:59:59,304 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 7639149275918227842 lease expired >>>>>> 2009-07-02 08:59:59,305 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -4243449001964507288 lease expired >>>>>> 2009-07-02 08:59:59,336 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 1015989167671983355 lease expired >>>>>> 2009-07-02 08:59:59,365 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 3137801875907893411 lease expired >>>>>> 2009-07-02 08:59:59,365 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -8325694931774559300 lease expired >>>>>> 2009-07-02 08:59:59,372 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -8936585826880409980 lease expired >>>>>> 2009-07-02 08:59:59,373 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -908187178943291682 lease expired >>>>>> 2009-07-02 08:59:59,380 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 2654166457442359069 lease expired >>>>>> 2009-07-02 08:59:59,381 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -6211248022427672712 lease expired >>>>>> 2009-07-02 08:59:59,381 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 3974694446665362397 lease expired >>>>>> 2009-07-02 08:59:59,388 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 7443667809791934770 lease expired >>>>>> 2009-07-02 08:59:59,389 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,954242,1245722360640 >>>>>> 2009-07-02 08:59:59,390 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,4603057,1245718674937 >>>>>> 2009-07-02 08:59:59,390 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableB,DATA\x7DATA\x20DATA\x7C1113950,1245707506310 >>>>>> 2009-07-02 08:59:59,391 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableB,NAME\x7DATA,\x20DATA\x7C440700,1245711086612 >>>>>> 2009-07-02 08:59:59,391 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableC,NAME\x7DATA,\x20DATA\x7C1304895,1246039336150 >>>>>> 2009-07-02 08:59:59,391 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,9320921,1245722360640 >>>>>> 2009-07-02 08:59:59,392 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableB,,1245707233007 >>>>>> 2009-07-02 08:59:59,392 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,706403,1245720721671 >>>>>> 2009-07-02 08:59:59,393 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableB,DATA\x7CTV\x20DATA\x7C1624424,1245711676808 >>>>>> 2009-07-02 08:59:59,393 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,3809913,1245718111373 >>>>>> 2009-07-02 09:00:02,049 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -2051187117514067432 lease expired >>>>>> 2009-07-02 09:00:02,057 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -5436750646911643669 lease expired >>>>>> 2009-07-02 09:00:02,057 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 3703189751852364720 lease expired >>>>>> 2009-07-02 09:00:02,065 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -1804107906626216054 lease expired >>>>>> 2009-07-02 09:00:02,065 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegion: >>>>>> Closed tableA,1578094,1245716374054 >>>>>> 2009-07-02 09:00:03,693 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 9131595104858116429 lease expired >>>>>> 2009-07-02 09:00:03,693 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 8992759827427237274 lease expired >>>>>> 2009-07-02 09:00:03,693 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -2019578407247616091 lease expired >>>>>> 2009-07-02 09:00:03,709 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> 3596045071882952182 lease expired >>>>>> 2009-07-02 09:00:03,753 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -7795892844843445855 lease expired >>>>>> 2009-07-02 09:00:03,789 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -3894684572515627828 lease expired >>>>>> 2009-07-02 09:00:12,649 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: Scanner >>>>>> -2055258947739971980 lease expired >>>>>> 2009-07-02 09:00:12,650 INFO org.apache.hadoop.hbase.Leases: >>>>>> regionserver/0.0.0.0:60020.leaseChecker closing leases >>>>>> 2009-07-02 09:00:12,650 INFO org.apache.hadoop.hbase.Leases: >>>>>> regionserver/0.0.0.0:60020.leaseChecker closed leases >>>>>> 2009-07-02 09:02:29,906 INFO >>>>>> org.apache.hadoop.hbase.regionserver.HRegionServer: compactions no >>>>>> longer >>>>>> limited >>> >> > > -- View this message in context: http://www.nabble.com/Adding-Removing-regionservers-tp24309642p24311778.html Sent from the HBase User mailing list archive at Nabble.com.
