DTrace probes?

[sax]

I have some DTrace probes added to a branch I created to test out #87 in our infrastructure. Would you be interested in having a pull request for these?

I can understand your response either way... Feature utility vs. feature maintenance. Just let me know!

[bleonard]

hey @sax - a few thoughts.
maybe we could generically hook those spots you found interesting in a callback or something. then people could do what they wanted. analytics_handler or something. for example if you just said dtrace maybe that ones built in but you could also give a proc or a class name.

I'm thinking there are lots of spots to allow named or generic callbacks like that. one case is from #85 where there is a way to have an override the pool selection.

@mnelson suggested

master_node_selector: 'Makara::NodeSelectors::SingleWithFailover'

[sax]

This sounds like a good solution. I'll work on a pull request now.

[bleonard]

@sax @jacobbednarz any thoughts on these two PRs (#126 and #103)?

I'm just catching up and attempting to be a good citizen here. Are you using either one of them in prod?

[sax]

I'm no longer at the company where we did this work. They are still using #103 in production, but I don't see any problems with going directly to ActiveSupport::Notifications (unless you want to eventually drop the hard dependency on ActiveSupport). It would be pretty easy to switch over the DTrace probes to hook into AS notifications rather than the custom notification module.

#126 doesn't provide any tests for the notifications, if you care about such things.

[bleonard]

Thanks @sax

[jacobbednarz]

The purpose behind my pull request was getting some sort of framework in
place so that we could monitor behaviour before launching it into
production. Due to the scale this was going to be used on, I wasn't
comfortable using this without some instrumentation that we could
benchmark against our existing stack and confirm this didn't introduce
performance regressions.

I will be revisiting the read/write split for our DB's however at this
stage, it won't be in the immediate future so you're free to do whatever
you'd like with the pull request. You're more than welcome to work on
that branch if you'd like to continue it.