Thanks for the detail explanation. BTW, are there any rule of thumb for how large should I reserve for those "in flight" memory ?
> So are you looking at the total process size (e.g. top) or are you looking at > the amount of memory the jvm says it is using (e.g. jmap -heap <pid>)? > > If you are looking at the process size (top) jvm doesn't ever give memory > back so over time the process will just get bigger and bigger as it will > spike in size before garbage collection can kick in an free enough memory. > If you are looking at jvm memory used then it will use the memory you said + > everything else "in flight". Stuff "in flight" includes any memory for the > IPC running, memory for return values, memory for compactions, memory for > general bookkeeping, etc. The biggest ones would be return values (and put > values) for IPC and memory used for compactions. > > ~Jeff > > On 11/1/2012 8:43 AM, 徐歷盛 wrote: >> What's the usage of region server heap used memory ? >> I originally thought it's roughly the sum of current memstore + blockcache >> + storefileindex. But in our environment, I have configured max heap to 20g >> , heap used memory is sometimes up to 19g. At that moment, storefileindex >> was 8g, blockcache was 1g, memstore was 1g. What's the rest 9g memory ? >> Thanks in advance. > > -- > Jeff Whiting > Qualtrics Senior Software Engineer > [email protected] >
