It looks like you can configure multiple hosts for GC and they'll use
ZooKeeper to perform failover (like the master).
Tracers -- You can run multiple tracer processes. You likely don't need
1:1 as you run tservers, but you can run a few if you're concerned about
it. They're not required for Accumulo operation.
Same for the monitor. If you need to have multiple running for failover
purposes, it looks like you can specify multiple and it will just launch
a monitor on each host you specified. There's no centralize URL you can
always hit here. You would have to check each one to find one that was,
unless you want to run some sort of reverse-proxy in front of them all.
_obligatory I just looked to source code to come to this conclusion_
On 11/5/13, 3:13 PM, Terry P. wrote:
I put my secondary namenode in the masters file for the first time with
this latest Accumulo 1.4.2 cluster deployment so it would run as a
Standby Accumulo Master which I read about in the User Guide. Recently
had the Master lose its Zookeeper lock (network glitch, being
researched), and was glad to see the secondary namenode Master process
took over as it should.
But if my Namenode / Accumulo Master server goes down, I also lose the
gc, monitor, and tracer processes as well. *Can I configure the
secondary namenode in gc, tracer, and monitor files as well, or should
they run on only one host at a time*? In this case, the GC also lost
its Zookeeper lock, which resulted in a cluster with no GC running at
all until I caught it.
Thanks in advance.
