On Tue, Mar 8, 2016 at 8:28 AM, Akmal Abbasov <akmal.abba...@icloud.com> wrote:
> Hi, > I'm testing HBase to choose the right hardware configurations for a heavy > write use case. I'm testing using YCSB. > The cluster consist of 2 masters, and 5 regionservers(4 cores, 14GB ram, > 4x512GB SSD). > I've created a new table in HBase, presplit it to 50 regions. I'm running > 3 clients each running 50 threads, to insert data. > What happens if you double the number of clients? > I'm using the default HBase settings. > Our defaults are intentionally conservative set for broad appeal. For now, there is an expectation that configs are adjusted to suit the loadings. > After running few tests, I can see that the cluster is underutilized, in > fact memory usage is around 30%. > Which memory? Java heap? Or the systems' memory? If java heap, we make broad allocations for cache and write-time memstore. You might allocate more to memstore if you are write-centric (Later versions of hbase try to do this ergonomically). > The main problem I see for now is compactions, compactionQueueLength is > growing very fast, and compaction process is always running. > Compactions running all the time while you are under write load is 'normal'. How are you seeing this manifest as a 'problem'? Show us a bit of your log from a regionserver and take a few thread dumps while it is running so we can make suggestion. > I found that there are hbase.regionserver.thread.compaction.small and > hbase.regionserver.thread.compaction.large > but couldn't find information regarding their default values. > Yes. This stuff is missing from the doc, in code only. Lets figure if they need adjustment first. > I am also planing to increase the regions number and the memstore size to > increase utilization of the cluster and performance. > Which other settings should be tuned to improve both utilization and > performance? > You've browsed this section http://hbase.apache.org/book.html#performance ? > Thank you. > > > I'm using HBase 0.98.7 and regionserver heap size is 7GB. > Can you use a later HBase? 1.2.0 just got released. St.Ack > > Regards, Akmal >
