Thanks all. Actually the problem happened due to accidentally remove some security policy which defines the ports to communicate between the servers and required by ZK to detect region servers. However, the problem leads me to the opportunity to know how to tune HBase for long GC pauses as well as others.
Regards, Joarder Kamal On 21 February 2013 15:18, ramkrishna vasudevan < [email protected]> wrote: > The two RS could have died due to GC or some connectivity issues with ZK. > Checking the logs would help us get a clear idea. > > REgards > Ram > > On Thu, Feb 21, 2013 at 7:09 AM, Joarder KAMAL <[email protected]> wrote: > > > Hi Ted, > > > > After login into the HBase UI I found two of my region servers were dead. > > Don't have any clue why. Master is still up and running for the past 4 > > days. > > Memory is still running pretty low without any workload and two region > > servers!! > > > > -------------------------------------------------- > > > > root@hdb1-01:/home/ubuntu# jps > > 1064 NameNode > > 1578 JobTracker > > 10770 Jps > > 2481 HRegionServer > > 2261 HMaster > > 1280 DataNode > > 1769 TaskTracker > > 2197 HQuorumPeer > > 1480 SecondaryNameNode > > -------------------------------------------------- > > root@hdb1-02:/home/ubuntu# jps > > 1492 HRegionServer > > 1315 TaskTracker > > 1137 DataNode > > 3290 Jps > > -------------------------------------------------- > > root@hdb1-03:/home/ubuntu# jps > > 1527 HRegionServer > > 1171 DataNode > > 7475 Jps > > 1349 TaskTracker > > > > -------------------------------------------------- > > PID found 2197, 2261 and 2481 for 'hbase' > > -------------------------------------------------- > > root@hdb1-01:/home/ubuntu# ps axo pid,ppid,rss,vsz | grep 2197 > > 2197 1 52248 1938732 > > -------------------------------------------------- > > root@hdb1-01:/home/ubuntu# ps axo pid,ppid,rss,vsz | grep 2261 > > 2261 1 108724 2007912 > > -------------------------------------------------- > > root@hdb1-01:/home/ubuntu# ps axo pid,ppid,rss,vsz | grep 2481 > > 2481 1 686252 2031376 > > -------------------------------------------------- > > root@hdb1-01:/home/ubuntu# free -m > > total used free shared buffers cached > > Mem: 1652 1616 36 0 51 305 > > > > -/+ buffers/cache: 1259 393 > > Swap: 895 8 887 > > > > > > Thanks a lot again ... > > > > > > Regards, > > Joarder Kamal > > > > > > > > On 21 February 2013 11:08, Ted Yu <[email protected]> wrote: > > > > > What do you see when you use 'ps aux | grep <pid>' command ? > > > A sample is shown below: > > > > > > USER PID %CPU %MEM VSZ RSS TT STAT STARTED > > > TIME COMMAND > > > tyu 16468 232.2 1.4 4974136 240528 s002 R+ 4:05PM > > > 2:11.15 > > > > > > > > > /System/Library/Java/JavaVirtualMachines/1.6.0.jdk/Contents/Home/bin/javadoc > > > -J-Xmx2048m @options @packages > > > > > > Please give us the VSZ and RSS readings. > > > > > > Thanks > > > > > > On Wed, Feb 20, 2013 at 3:56 PM, Joarder KAMAL <[email protected]> > > wrote: > > > > > > > Sorry may be I didn't clarify the question properly. > > > > > > > > Q2. As per the default setting maxHeapMB size is 991, so in > saturation > > > > condition HBase can't use more RAM (even if it is available, for > > example > > > > the system memory size is 4GB) than this defined size, is it right? > > > > > > > > > > > > Many thanks again... > > > > > > > > On 21 February 2013 10:48, Ted Yu <[email protected]> wrote: > > > > > > > > > I am not familiar with monitoring tools on EC2. > > > > > > > > > > You can use Ganglia to monitor hadoop / HBase. > > > > > > > > > > Cheers > > > > > > > > > > On Wed, Feb 20, 2013 at 3:42 PM, Joarder KAMAL <[email protected] > > > > > > wrote: > > > > > > > > > > > Hi Ted, > > > > > > > > > > > > Thanks for the reply. > > > > > > > > > > > > Q1. Cleared now. Sorry I didn't count the -ROOT- and .META. > tables > > > > > > Q2. Not clear. Could explain a bit more? I am using the default > > > > setting. > > > > > > > > > > > > Thanks again. > > > > > > > > > > > > > > > > > > On 21 February 2013 10:36, Ted Yu <[email protected]> wrote: > > > > > > > > > > > > > bq. but when I click to view the table details it shows there > > are 5 > > > > > > > regions. > > > > > > > > > > > > > > Did you include -ROOT- and .META. tables above ? > > > > > > > > > > > > > > bq. as you can see the maxHeapMB size is 991 > > > > > > > > > > > > > > Attachment is automatically stripped from your email. FYI > > > > > > > > > > > > > > On Wed, Feb 20, 2013 at 3:26 PM, Joarder KAMAL < > > [email protected] > > > > > > > > > > wrote: > > > > > > > > > > > > > > > Dear All, > > > > > > > > > > > > > > > > I am currently running a 3 node HBase cluster with Amazon EC2 > > > small > > > > > > > > instance (1CPU, 1.7GB Mem). After running a simple workload > > (type > > > > A) > > > > > > > using > > > > > > > > YCSB benchmarking tool, I noticed in the Web UI that the > number > > > of > > > > > > > regions > > > > > > > > in the 3 region servers are 7 but when I click to view the > > table > > > > > > details > > > > > > > it > > > > > > > > shows there are 5 regions. I am a bit confuse. Does the Web > UI > > > > > showing > > > > > > > > wrong results? How can I check region details from the > shell/is > > > > there > > > > > > any > > > > > > > > other command line tools for that? I am using Hbase 0.94.3 > (as > > it > > > > is > > > > > > the > > > > > > > > latest version compatible with YCSB at this moment) with > > > > > Hadoop-1.0.4. > > > > > > > > > > > > > > > > Another thing, as you can see the maxHeapMB size is 991 > > (default > > > > > > setting) > > > > > > > > then whenever I am running workloads the server free memory > > > status > > > > is > > > > > > > > terrible - almost 0MB for 1M/10M transactions > > (YCSB/Workload-A). > > > My > > > > > > > > question is if the maxHeapMB is fixed at 1GB then why I am > > > loosing > > > > > > extra > > > > > > > > 700MB memory? How can I monitor cpu/memory/io usage for > > > individual > > > > > > > cluster > > > > > > > > components (HBase/Hadoop/MapRed/ZK, etc.)? Is there any tool > > > > > available > > > > > > > with > > > > > > > > HBase? > > > > > > > > > > > > > > > > Thanks a lot. > > > > > > > > > > > > > > > > > > > > > > > > [image: Inline images 1] > > > > > > > > > > > > > > > > > > > > > > > > Regards, > > > > > > > > Joarder Kamal > > > > > > > > > > > > > > > > ------------------------------------------ > > > > > > > > PhD Student > > > > > > > > Gippsland School of Information Technology, > > > > > > > > Faculty of Information Technology, > > > > > > > > MONASH University > > > > > > > > Churchill VIC, Australia. 3842 > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > > >
