Hi all: These days my friend and I did some performance tests on zookeeper. We found the performance of zookeeper is not as good as it is described in the Zookeeper Overview ( http://hadoop.apache.org/zookeeper/docs/r3.3.2/zookeeperOver.html) . In the Zookeeper Overview, the "ZooKeeper Throughput as the Read-Write Ratio Varies" shows that in a ensemble of 3 Zookeeper server, the throughput can reach about 80000, if the requests are all reads. However, we cannot get results like that in our performance test with the synchronized interface, zkpython.
Here is some of our test results: (3 zookeeper ensemble, 8 core CPU, 2.4GHZ, 16 RAM, Linux 2.6.9) § 1 client server，1 process per client server，connect 1 zookeeper server，all reads：cpu：8%~9%，qps：2208，latency：0.000453s § 1 client server，1 process per client server，connect all 3 zookeeper server，all reads：cpu：8%~9%，qps：2376.241573 ，latency:0.000421s § 1 client server，1 process per client server，connect all 3 zookeeper server，all reads，cpu：10%~20%，qps：15600，latency：0.000764s *§ 1 client server，30 process per client server，connect all 3 zookeeper server，all reads，cpu：10%~20%，qps：15200，latency：* *§ 2 client server，30 process **per client server**，connect all 3 zookeeper server，all reads，cpu：10%~20%，qps：15800，latency：0.003487* qps means "query per second", that is throughput. The result shows that when adding more client server, the utilization rate of CPU don't increase, and the throughput don't increase much. It seems that the throughput won't reach 80000, even if we add 28 more client servers to reach the number you mentioned in the Zookeeper Overview. Maybe I've done the tests wrong. Is there any particular thing I should pay attention to in this case? We set the max java heap size to 12GB in our test. *Could you tell me the details about how you do the performance test, from which you get the results showed in the Zookeeper Overview?* -- With Regards! Ye, Qian
