Re: checkpoint patches

* Robert Haas (robertmhaas(at)gmail(dot)com) wrote:
> On Thu, Mar 22, 2012 at 3:45 PM, Stephen Frost <sfrost(at)snowman(dot)net> wrote:
> > Well, those numbers just aren't that exciting. :/
>
> Agreed. There's clearly an effect, but on this test it's not very big.

Ok, perhaps that was because of how you were analyzing it using the 90th
percetile..?

> See attached. It looks a whole lot like the tps graph, if you look at
> the tps graph upside with your 1/x glasses on.

Well, what I'm looking at with this graph are the spikes on master up to
near 100ms latency (as averaged across 10 seconds) while
checkpoint-sync-pause-v1 stays down closer to 60 and never above 70ms.
That makes this patch look much more interesting, in my view..

I'm assuming there's some anomaly or inconsistincy with the last few
seconds, where the latency drops for master and spikes with the patch.
If there isn't, then it'd be good to have a longer run to figure out if
there really is an issue with the checkpoint patch still having major
spikes.

Thanks,

Stephen