I issued two more disable commands and looked at the .META RS. The last log entry looks like:
11/03/01 00:29:14 INFO regionserver.HLog: Roll /hbase/.logs/<RS_HOSTNAME>,60020,1298935751670/hlog .dat.1298935752660, entries=13527, calcsize=3839046, filesize=2560143. New hlog /hbase/.logs/<RS_HOSTNAME>,60020,1298935751670/hlog.dat.1298939354072 I issued the command at: 00:34:59, the client debug message has nothing but "11/03/01 00:34:59 DEBUG zookeeper.ClientCnxn: Got ping response for sessionid:0x12e6e938e9c000b after 90ms" until 00:47:19. Then all of a sudden it outputs the following: 0:47:28 DEBUG client.HConnectionManager$TableServers: Cache hit for row <> in tableName .META.: location server 10.146.14.38:60020, location region name .META.,,1 11/03/01 00:47:28 DEBUG zookeeper.ZooKeeperWrapper: Read ZNode /hbase/root-region-server got 10.146.14.38:60020 11/03/01 00:47:28 DEBUG client.HConnectionManager$TableServers: Found ROOT at 10.146.14.38:60020 11/03/01 00:47:28 DEBUG client.HConnectionManager$TableServers: Cached location for .META.,,1 is 10.146.14.38:60020 11/03/01 00:47:30 DEBUG client.HConnectionManager$TableServers: Rowscanned=261, rowsOffline=3 11/03/01 00:47:30 DEBUG client.HBaseAdmin: Sleep. Waiting for all regions to be disabled from myTable 11/03/01 00:47:31 DEBUG client.HBaseAdmin: Wake. Waiting for all regions to be disabled from myTable Here's the full thread dump of the .META RS from 00:34:59 to 00:47:31 http://pastebin.com/Ywwx8afQ I hope I compiled some useful information here. I am pretty lost at this point, I would really appreciate your help! Thanks! On Mon, Feb 28, 2011 at 2:58 PM, Jean-Daniel Cryans <[email protected]> wrote: > Ok so no debug from the disable command? BTW you should output your GC > somewhere else like the .out file or a completely separate file. > > J-D > > On Mon, Feb 28, 2011 at 2:54 PM, Nanheng Wu <[email protected]> wrote: >> I see, so I should jstack the .META region. I'll do that. >> >> The master log pretty much looks like this: should I grep for >> something specific? >> >> 11/02/28 22:52:56 INFO master.BaseScanner: RegionManager.rootScanner >> scan of 1 row(s) of meta region complete >> 2011-02-28T22:52:57.138+0000: 263241.014: [GC 263241.014: [ParNew: >> 19136K->2112K(19136K), 0.0033350 secs] 378606K->36159 >> 6K(641944K) icms_dc=0 , 0.0034330 secs] [Times: user=0.02 sys=0.00, >> real=0.00 secs] >> 2011-02-28T22:53:04.956+0000: 263248.832: [GC 263248.832: [ParNew: >> 19068K->2112K(19136K), 0.0029690 secs] 378552K->36163 >> 0K(641944K) icms_dc=0 , 0.0030460 secs] [Times: user=0.02 sys=0.00, >> real=0.00 secs] >> 2011-02-28T22:53:12.664+0000: 263256.540: [GC 263256.541: [ParNew: >> 19136K->2112K(19136K), 0.0037690 secs] 378654K->36164 >> 7K(641944K) icms_dc=0 , 0.0038660 secs] [Times: user=0.01 sys=0.00, >> real=0.01 secs] >> 2011-02-28T22:53:20.608+0000: 263264.484: [GC 263264.484: [ParNew: >> 19136K->1810K(19136K), 0.0032600 secs] 378671K->36134 >> 6K(641944K) icms_dc=0 , 0.0033470 secs] [Times: user=0.02 sys=0.00, >> real=0.01 secs] >> 2011-02-28T22:53:28.278+0000: 263272.154: [GC 263272.154: [ParNew: >> 18834K->2112K(19136K), 0.0029870 secs] 378370K->36166 >> 1K(641944K) icms_dc=0 , 0.0030670 secs] [Times: user=0.01 sys=0.00, >> real=0.01 secs] >> 2011-02-28T22:53:35.919+0000: 263279.795: [GC 263279.795: [ParNew: >> 19136K->1747K(19136K), 0.0037090 secs] 378685K->36129 >> 8K(641944K) icms_dc=0 , 0.0037920 secs] [Times: user=0.02 sys=0.00, >> real=0.01 secs] >> 11/02/28 22:53:36 INFO master.ServerManager: 9 region servers, 0 dead, >> average load 760.2222222222222 >> >> >> On Mon, Feb 28, 2011 at 2:49 PM, Jean-Daniel Cryans <[email protected]> >> wrote: >>> Are you able to tell if that call in metaScanner is hanging or it's >>> making multiple calls to the .META. region? >>> >>> If former, then jstack the region server that hosts .META. and see >>> where it's blocked. >>> >>> if latter, then it means your .META. region is slow? Again, what's >>> going on on the RS that hosts .META.? >>> >>> Finally, what's the master's log like during that time? >>> >>> J-D >>> >>> On Mon, Feb 28, 2011 at 2:41 PM, Nanheng Wu <[email protected]> wrote: >>>> J-D, >>>> >>>> Thanks so much for your help so far! I sent disable commands on 4 >>>> rather small tables and they got stuck for a long time again, so I >>>> took jstack of the master. From what I can tell, all disableTable >>>> calls are blocked by a meta scanner thread (sample log below). At the >>>> moment there were no other requests to the server at all. How should I >>>> investigate this further? If it helps, here's some background: I have >>>> several datasets, each of them is in a separate table; Our data >>>> pipeline produces a new version of each dataset everyday and only the >>>> lastest version should be used. This is how the data is loaded: for >>>> each dataset 1) run a MR job and outputs HFiles 2) call loadTable.rb >>>> to create a new table 3) disable and drop the previous version. As a >>>> result some calls to load table and drop table would overlap. Please >>>> let me know if something stands out to you as a potential culprit. >>>> Thanks! >>>> >>>> BTW, I am running Hadoop 0.20.2 with HBase 0.20.6 >>>> >>>> Thread 47 (IPC Server handler 13 on 60000): >>>> State: BLOCKED >>>> Blocked count: 3801 >>>> Waited count: 72719 >>>> Blocked on java.lang.Object@75ac522c >>>> Blocked by 27 (RegionManager.metaScanner) >>>> Stack: >>>> >>>> org.apache.hadoop.hbase.master.TableOperation.process(TableOperation.java:154) >>>> org.apache.hadoop.hbase.master.HMaster.disableTable(HMaster.java:842) >>>> sun.reflect.GeneratedMethodAccessor9.invoke(Unknown Source) >>>> >>>> sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:25) >>>> java.lang.reflect.Method.invoke(Method.java:597) >>>> org.apache.hadoop.hbase.ipc.HBaseRPC$Server.call(HBaseRPC.java:657) >>>> >>>> org.apache.hadoop.hbase.ipc.HBaseServer$Handler.run(HBaseServer.java:915) >>>> >>>> >>>> Thread 27 (RegionManager.metaScanner): >>>> State: WAITING >>>> Blocked count: 1526058 >>>> Waited count: 1488998 >>>> Waiting on org.apache.hadoop.hbase.ipc.HBaseClient$Call@4dd44ab0 >>>> Stack: >>>> java.lang.Object.wait(Native Method) >>>> java.lang.Object.wait(Object.java:485) >>>> org.apache.hadoop.hbase.ipc.HBaseClient.call(HBaseClient.java:722) >>>> org.apache.hadoop.hbase.ipc.HBaseRPC$Invoker.invoke(HBaseRPC.java:333) >>>> $Proxy1.get(Unknown Source) >>>> >>>> org.apache.hadoop.hbase.master.BaseScanner.checkAssigned(BaseScanner.java:543) >>>> >>>> org.apache.hadoop.hbase.master.BaseScanner.scanRegion(BaseScanner.java:192) >>>> >>>> org.apache.hadoop.hbase.master.MetaScanner.scanOneMetaRegion(MetaScanner.java:73) >>>> >>>> org.apache.hadoop.hbase.master.MetaScanner.maintenanceScan(MetaScanner.java:129) >>>> org.apache.hadoop.hbase.master.BaseScanner.chore(BaseScanner.java:153) >>>> org.apache.hadoop.hbase.Chore.run(Chore.java:68) >>>> >>>> >>>> >>>> >>>> On Fri, Feb 25, 2011 at 10:23 AM, Jean-Daniel Cryans >>>> <[email protected]> wrote: >>>>> An hour to disable? That doesn't sound right at all :) >>>>> >>>>> I would approach this problem like I generally do with HBase issue, >>>>> first check the master log for any weirdness regarding my problem (in >>>>> this case, grep for the table name). >>>>> >>>>> Then I would look the region server log(s) of the nodes that were >>>>> hosting regions from that table. You should see the steps taken to >>>>> disable the regions (starting to close, flush, region completely >>>>> closed). >>>>> >>>>> If you are able to do it while it's taking a very long time to >>>>> disable, try to jstack the process the seems to be hanging. >>>>> >>>>> Finally, like I said in another thread, there's a bug in 0.20.6 that >>>>> almost prevent disabling a table (or re-enabling) if any region >>>>> recently split and the parent wasn't cleaned yet from .META. and that >>>>> is fixed in 0.90.1 >>>>> >>>>> J-D >>>>> >>>>> On Thu, Feb 24, 2011 at 11:37 PM, Nanheng Wu <[email protected]> wrote: >>>>>> I think you are right, maybe in the long run I need to re-architect my >>>>>> system so that it doesn't need to create new and delete old tables all >>>>>> the time. In the short term I am having a really hard time with the >>>>>> disabling function, I ran a disable command on a very small table >>>>>> (probably dozen of MBs in size) and are no client using the cluster at >>>>>> all, and that took about 1 hour to complete! The weird thing is on the >>>>>> web UI only the region server carrying the META table has non-zero >>>>>> requests, all other RS have 0 requests the entire time. I would think >>>>>> they should get some request to flush the memstore at least. I *am* >>>>>> using the same RS nodes for some map reduce job at the time and top >>>>>> shows the memory usage is almost full on the META region. Would you >>>>>> have some idea of what I should investigate? >>>>>> Thanks so much. >>>>> >>>> >>> >> >
