See the troubleshooting page, some apropos detail there (esp relative to
ZK servers are sensitive to IO (disk/network) latency. As long as you
aren't very sensitive latency requirements it should be fine. If the
machine were to swap for example, or the JVM were to go into long term
GC (visualization in particular kills jvm gc) that would be bad.
Best practice for "on-line production serving" is 5 dedicated hosts with
"shared nothing", physically distributed thoughout the data center (5
hosts in a rack might not be the best idea for super reliability).
There's alot of lee-way though, many ppl run with 3 and spof on switch
David Rosenstrauch wrote:
I'm contemplating an upcoming zookeeper rollout and was wondering what
the zookeeper brain trust here thought about a network deployment question:
Is it generally considered bad practice to just deploy zookeeper on our
existing hdfs/MR nodes? Or is it better to run zookeeper instances on
their own dedicated nodes?
On the one hand, we're not going to be making heavy-duty use of
zookeeper, so it might be sufficient for zookeeper nodes to share box
resources with HDFS & MR. On the other hand, though, I don't want
zookeeper to become unavailable if the nodes are running a resource
intensive job that's hogging CPU or network.
What's generally considered best practice for Zookeeper?