Please see http://hbase.apache.org/book.html#perf.reading
I guess you use 0.90.4 because of Nutch integration. Still 0.90.x was way too old. bq. HBase has a heapsize of 1.5 Gigs This is not enough memory for good read performance. Please consider giving HBase more heap. Cheers On Sat, Jan 10, 2015 at 4:04 PM, Dave Benson <[email protected]> wrote: > Hi HBase users, > > I'm working HBase for the first time and I'm trying to sort out a > performance issue. HBase is the data store for a small, focused web crawl > I'm performing with Apache Nutch. I'm running in pseudo-distributed mode, > meaning that Nutch, HBase and Hadoop are all on the same machine. The > machine's a few years old and has only 4 gigs of RAM - much smaller than > most HBase installs, I know. > > When I first start my HBase processes I get about 60 seconds of fast > performance. Hbase reads quickly and uses a healthy portion CPU cycles. > After a minute or so, though, HBase slows dramatically. Reads sink to a > glacial pace, and the CPU sits mostly idle. > > I notice this pattern when I run Nutch - particularly during read-heavy > operations - but also when I run a simple row counter from the shell. > > At the moment " count 'my_table' " takes almost 4 hours to read through 500 > 000 rows. The reading is much faster at the start than the end. In the > first 30 seconds, HBase counts 37000 rows, but in the 30 seconds between > 8:00 and 8:30, only 1000 are counted. > > Looking through my Ganglia report I see a brief return to high performance > around 3 hours into the count. I don't know what's causing this spike. > > > Can anyone suggest what configuration parameters I should change to improve > read performance? Or what reference materials I should consult to better > understand the problem? Again, I'm totally new to HBase. > > I'm using HBase 0.90.4 and Hadoop 1.2.2. HBase has a heapsize of 1.5 Gigs. > > Here's a Ganglia report covering the 4 hours of " count 'my_table' ": > http://imgur.com/Aa3eukZ > > Please let me know if I can provide any more information. > > Many thanks, > > > Dave >
