-Re: replication - how do I know the status?
Jean-Daniel Cryans 2012-09-13, 21:48
On Thu, Sep 13, 2012 at 2:28 PM, Neil Yalowitz <[EMAIL PROTECTED]> wrote:
> This is a great answer, I can see that particular ganglia metric sharply
> increased when the issue began. Thanks much.
> One followup question:
> Can a distressed slave cluster cause performance issues on the master
> cluster? It appears our performance problem was occurring on the slave
> peer, but the master cluster almost crashed as well. I'm trying to
> determine if that was a coincidence or something more...
That's a tougher one, but FWIW the work required on the master cluster
is low compared to what the slave has to do; the master just needs to
read a bunch of edits and send them whereas the slave has to write
them to the WAL, add them to the MemStore, eventually flush and
Also if you had a big MR job that ran on the master and that inserted
a lot of data, I would assume that it made everything slower. If it's
also what caused swapping then it would explain a lot.