Yes, the explanation helped a lot. Thank you! Kindly regards Wojciech Indyk
2015-07-02 8:44 GMT+02:00 Esteban Gutierrez <[email protected]>: > Hi Wojciech, > > From the memory metrics and the up time of the RS reported by top seems > that JVM has been running for a while, so a good part of the memory pages > available for the JVM process have been touched and now are considered as > used by to OS. Same thing can happen if -Xms is present and its larger than > the default or equal to -Xmx causing those memory pages to be "touched" and > considered by the OS as used even when the JVM hasn't claimed that memory > for object creation. > > BTW, usually when you monitor memory utilization by HBase, you only monitor > the JVM metrics and not the memory usage reported by the OS for the HBase > process, since that usually is (or will become) a constant value during the > life of the process. > > I hope that helps. > > esteban. > > > > > -- > Cloudera, Inc. > > > On Wed, Jun 24, 2015 at 2:27 AM, Wojciech Indyk <[email protected]> > wrote: > >> hello! >> I try to monitor memory of my regionservers. I have HBase 0.98 on CDH >> 5.3.1. >> I can see inconsistency between HBase metrics (here is metrics dump >> from HBase UI): >> "name" : "Hadoop:service=HBase,name=JvmMetrics", >> "modelerType" : "JvmMetrics", >> "tag.Context" : "jvm", >> "tag.ProcessName" : "IPC", >> "tag.SessionId" : "", >> "tag.Hostname" : "sqhadoop04.gazeta.pl", >> "MemNonHeapUsedM" : 93.26676, >> "MemNonHeapCommittedM" : 94.89844, >> "MemNonHeapMaxM" : -9.536743E-7, >> "MemHeapUsedM" : 8513.122, >> "MemHeapCommittedM" : 20330.25, >> "MemHeapMaxM" : 20330.25, >> "MemMaxM" : 20330.25, >> and system "top" monitoring (all of my hbase processes on the >> regionserver): >> PID USER PR NI VIRT RES SHR S %CPU %MEM TIME+ COMMAND >> 19700 hbase 20 0 22.3g 16g 23m S 1.3 8.7 479:47.53 java >> 19874 hbase 20 0 107m 2404 556 S 0.7 0.0 9:16.13 hbase.sh >> 19873 hbase 20 0 105m 908 556 S 0.0 0.0 0:00.00 hbase.sh >> >> As we can see there is 16GB according to "top" and ~8.5GB according to >> HBase. Why these values are different? >> >> Kindly regards >> Wojciech Indyk >>
