I'd love to see a GC log, and yes it can be possible for ParNew to take a long long time.
Thanks, -ryan On Sun, Sep 19, 2010 at 1:20 AM, Tao Xie <xietao.mail...@gmail.com> wrote: > At first when I running the test, one of my regionserver shuts down. I found > the gc has problems on that node. Then I enabled the jvm options listed in > http://wiki.apache.org/hadoop/PerformanceTuning. After that, the test runs > well. I checked the log and I do not know if it's normal for ParNew to take > as long as 500 ms. I will attach a snippet of that if necessary. > > Thanks. > > > 2010/9/19 Ryan Rawson <ryano...@gmail.com> > >> What does your GC situation look like? >> >> >> >> On Sun, Sep 19, 2010 at 1:05 AM, Tao Xie <xietao.mail...@gmail.com> wrote: >> > Now my scenario is running ycsb doing heavy read. I compared the results >> of >> > setting hfile.block.cache.size to 0.2 with 0. I found with the factor 0 >> the >> > hbase metric 'get_avg_time' is even smaller. Maybe I should turn off >> block >> > cache in such scenario. I wonder if there are performance tests show the >> > benefits of block cache? Or there are other configurations for me to pay >> > attention to? >> > >> > Btw, I give hbase 18G memory. >> > >> >
