MiqQueue - remove MiqWorker lookup

[kbrock]

For MiqQuery.get, we perform an unneeded worker lookup, which is always the same for a given process.

ms	bytes	objects	query	query ms	rows	comments
1,894.9	31,002,739	353,789	602	1,373.5	955	count#before-1
1,778.1	26,014,249	289,589	502	1,328.1	955	count#after-5
6.2%	16%	18%	17%	3.3%	0	difference

---

TMI

MiqWorker.my_worker ; 100.times { MiqQueue.put(:class_name  => 'MyClass', :method_name => 'method1', :args => [1, 2]) }
bookend("miq_queue.count") { 102.times { MiqQueue.get } }

I highlighted theSELECT which is present before but not after.

ms	query	query ms	rows	comments
1,900.1	602	1,356.4	955	count#after-1
448.1	102	448.1		.SELECT COUNT(count_column)
458.4	100	435.0	955	.SELECT "miq_queue".*
64.9	100	54.9		.SELECT "miq_workers".*
43.8	100	43.8		.BEGIN
261.6	100	261.6		.UPDATE "miq_queue" SET "state" = 'dequeue', "handler_id" = 1, "handler_type" = 'MiqServer', "updated_on" = .{28}, "lock_version" = 1
79.6	100	79.6		.COMMIT

The numbers I collected for this one were a little less consistent, but make they do show the trend

ms	bytes	objects	query	query ms	rows	comments
1,894.9	31,002,739	353,789	602	1,373.5	955	count#before-1
1,900.1	31,002,725	353,789	602	1,356.4	955	count#before-2
2,008.4	31,002,759	353,789	602	1,477.2	955	count#before-3
1,856.9	31,003,215	353,789	602	1,331.8	955	count#before-4

ms	bytes	objects	query	query ms	rows	comments
1,816.7	26,013,787	289,589	502	1,368.8	955	count#after-1
1,820.6	26,013,789	289,589	502	1,372.6	955	count#after-2
1,857.9	26,013,819	289,589	502	1,393.4	955	count#after-3
1,771.0	26,014,391	289,589	502	1,317.5	955	count#after-4
1,778.1	26,014,249	289,589	502	1,328.1	955	count#after-5

[jrafanie]

Maybe call it handler instead of w in a second commit?

[kbrock]

I like that better - BUT, after looking at MiqQueue.get I have another optimization here :)

[miq-bot]

Checked commits kbrock/manageiq@a568b74~...c340673 with ruby 2.2.6, rubocop 0.47.1, and haml-lint 0.20.0
2 files checked, 0 offenses detected
Everything looks good. 👍

[isimluk]

👍

[jrafanie]

@kbrock what happens with subclasses that call my_worker? MiqGenericWorker.my_worker as an example. Is it sharing a class variable or is it not shared?

[jrafanie]

It might be weird if we're in a priority worker process and MiqGenericWorker.my_worker returned a MiqPriorityWorker row.

[jrafanie]

I think this is ok, but it's kinda weird if subclasses can return rows of not of it's type.

[kbrock]

Will multiple workers run on the same pid?

[jrafanie]

@kbrock no, I guess what I'm saying is it doesn't really make sense at the subclass level. We only want this on MiqWorker and not be inherited. I'm fine with it, just curious. I wasn't sure if you tried it out.