HI Chad, The maximum number of zookeeper servers we have tested with is 13. Even with 13 the performance starts to degrade very quickly (compared to ensemble of 5 and 7). I am not sure we have the current numbers (we have made 3x or so performance improvements) but with the old number in zookeeper.pdf on http://wiki.apache.org/hadoop/ZooKeeper/ZooKeeperPresentations
The slide is at the end. You can see that the performance drops with 13 servers. We usually suggest 5 or 7 servers for ZooKeeper. We can get around 20K-30K writes per second and more than 50K reads per second from an ensemble of 5 servers (as of now with performance enhancements). With 5 servers you can tolerate a failure of 2 nodes. Please take a look at zookeeper presentations - http://wiki.apache.org/hadoop/ZooKeeper/ZooKeeperPresentations To find out more about Zookeeper. What is the rationale behind having such a huge amount of zookeeper servers? Thanks mahadev On 3/3/09 5:30 PM, "Chad Harrington" <[email protected]> wrote: > Clearly Zookeeper can handle ensembles of a dozen or so servers. How large > an ensemble can one build with Zookeeper? 100 servers? 10,000 servers? > Are there limitations that make the system unusable at large numbers of > servers? > > Thanks,
