[mythtv-users] ensuring mythbackend will be idle for db optimize

[Jerome Yuzyk]

On Tuesday, September 22, 2015 09:53:38 AM Jerome Yuzyk wrote:
> 
> Fortunately MythShutdown can give me an Idle status like MythWelcome would use. 
> 
> But I can take a little from https://www.mythtv.org/wiki/Upcoming_Parse.pl to see what might be coming and how soon, and with MythShutdown I can get a fair idea of whether the backend is and will be idle in a dozen lines of Perl so far.
> 
> A fair idea. A MythFilldatabase might be looming. And I might be watching or listening on the frontend. Not usually, but I'd like to be complete. So I'm adding that now.

I tinkered over the afternoon and made something that will report on various "busy-ness" aspects of my setup, to test whether they can be used in production.

    http://pastebin.com/XpMeBGUm 
    (expires in 30 days because it'll be better by then)

MythShutdown is the workhorse for most of what matters "in-progress": recording, commflagging, and transcoding. Things outside that are less-distinct, though MythShutdown may be doing more than I can see from its public docs. Watching a recording (I skip a lot) is probably the most DB-active activity left. Maybe importing music/videos, but I don't use them to be able to test.

Then there are things that are coming up. Avoiding an upcoming recording (only the first matters generally) is easy, avoiding an upcoming MythFillDatabase less so and is a hack just for me (or others using the defaults) right now. 


These are 3 example test cases, one near, one far, one with the frontend playing a recording. 

:r! perl % 600
Checking for Idle now or within 600 seconds (10.00 minutes; 0.17 hours)
  Backend: -idle-
  Frontend: -idle-
  Next Recording in: 9799 seconds (163.32 minutes; 2.72 hours) *
  Next DB Fill in: 49339 seconds (822.32 minutes; 13.71 hours) -idle-
----> N Busy: 0 ----> Decision: IDLE

:r! perl % 60000
Checking for Idle now or within 60000 seconds (1000.00 minutes; 16.67 hours)
  Backend: -idle-
  Frontend: -idle- 
  Next Recording in: 9967 seconds (166.12 minutes; 2.77 hours) [BUSY]
  Next DB Fill in: 49507 seconds (825.12 minutes; 13.75 hours) [BUSY]
----> N Busy: 2 ----> Decision: BUSY

* s/''/'-idle-'/ line 168

:r! perl % 600
Checking for Idle now or within 600 seconds (10.00 minutes; 0.17 hours)
  Backend: -idle-
  Frontend: [BUSY]
  Next Recording in: 8371 seconds (139.52 minutes; 2.33 hours)-idle
  Next DB Fill in: 47911 seconds (798.52 minutes; 13.31 hours) -idle-
----> N Busy: 1 ----> Decision: BUSY


Once this shakes out I'll make it into a test for Go/NoGo for other DB-touching operations, like DB backups. 

I'm sure it can be tons better, and I would appreciate knowing how. What is the best documentation of the Services API that I can get for my 0.27.4 setup? The wiki can only go so far, I understand, and looks to be behind what I have. Does anyone have more examples of using the API that aren't Google-able?

-- 
A little of Jerome's MythTV World: http://mythtv.bss.ab.ca