Hi Sam, Just a clarifiaction, will a host going down fire 625 * 39 watches? That is ~ 24000 watches per host being down.
You can take a look at http://wiki.apache.org/hadoop/ZooKeeper/ServiceLatencyOverview about watches and latencies and hw requirements. Please do take a look and if it doesn't answer your questions, we should add more documentation. Thanks Mahadev On 12/16/10 7:42 PM, "Samuel Rash" <[email protected]> wrote: Hello, I am looking to run about 40 zookeeper clients with the following watch properties: 1. Up to 25,000 paths that every host has a watch on (each path has one child and the watch is one for that child, an ephemeral node, being removed) 2. An individual host "owns" 625 of these paths in this example; one going down will fire 625 watches to the other 39 hosts Is there any limit on the rate at which these watches can be sent off? What's the right size cluster? (3? 5?) Does it need to be dedicated hw? Thanks, Sam
