1424: Quick spoiling of the library [#8481]

[willyvds]

Magic Nodes is (sometimes) very slow with MM4.

The following mask takes half a second (0.38+0.16+0.00) in MM3 (3.2.5.1306) and almost 30 seconds elapsed (0.48+8.22+18.08) with MM4 (4.0.0.1418).
Mask: Test|Child of:Files to Edit|Position:First child|Filter:Genre = "Pop"\<Lyricist>

Far more complicated masks (by my standards) take less than a second.

Regards, Willy

[willyvds]

1421: this simple mask still takes 30 seconds.
Regards, Willy

[willyvds]

This problem is caused by MM4 "spoiling" the library rather quickly, I think.

I notice the following:
- the above simple Magic Nodes mask takes 0.3 sec in MM3
- in MM4 it takes 30 sec
- after a FULL optimization of the library, MM4 also takes 0.3 sec
- an hour or two later, performance is back to the very slow level

Note that a quick optimization does not help, it must be a full optimization. But the effect is undone by just a few hours of monkeying.
I've noticed this several times, but I cannot (yet) indicate in particular what causes the slowdown.

Regards, Willy

[rusty]

Hi Willy,

This query takes a fraction of a second for me on a well used library of 22k tracks. How large is your library? Would you mind sharing it with me so that we can attempt to replicate the issue?

Thanks.

-Rusty

[willyvds]

Rusty,

I happened to check the test mask an hour ago, then it took less than 1 second. Since then, I've played a couple of songs and added 1 album art. Now the mask takes 30 seconds!
After these 30 seconds, MM keeps on "reading files", for more than 10 minutes. In the meantime, I cannot click on the items in the upper 3 browsers.

A full library clean up solves this issue, but I've done that just a few days ago. It shouldn't be necessary to do that so often.

I will send you the link via PM.

Regards, Willy

[willyvds]

First: sorry for posting in a new thread, I thought that's how it should be done.

Anyway, it still strikes me that our library gets easily "spoiled". I have to do a full clean up every one or two weeks in order to keep performance decent.

More precisely: sometimes MM becomes really very, very slow. Particularly Magic Nodes and similar add ons. It is my experience that this improves greatly if I do a full clean up of the library. Note that the DB is not corrupt, and the content is okay. I find it just a bit annoying to have to do this clean up every other week or so.

So some questions:
- Is there a rule of thumb how often the library has to be cleaned? Is it normal that we have to do this so often?
- What could be the explanation for this? Could we do anything to prevent the spoiling?

Regards, Willy

[jiri]

Willy,

normally there really shouldn't be any need for frequent cleaning or maintaining library. In MM4 it actually shouldn't be needed at all, since we do some basic analysis after each scan of significant amount of tracks. There definitely shouldn't be any change after just using the library. It looks like there's something going wrong on your machine. We could start by generating a debug log and sending it to me.

Thanks,
Jiri

[Lowlander]

What scripts are involved in your install? Especially tagging and auto-tagging scripts? They might be involved in database spoiling.

[willyvds]

We have a bunch of add ons (Magic Nodes, Lyricator, Tagging inconsistencies etc). Is that what you mean?
Is this a known problem of one of them? Can we do anything to reduce the problem?
Regards, Willy

[Lowlander]

Yes, that's what I meant. The ones that modify the database (like the ones that tag) might be the cause behind this spoiling. I wouldn't know if a specific addon is to blame, or that MediaMonkey poorly handles addons that update the database.

[rusty]

Willyvds,

I think I was able to reproduce the problem you're experiencing, though the problem wasn't that bad because although mm showed 'Reading files...' indefinitely, the query appeared to complete, and the UI was functional.

See details at:
http://www.ventismedia.com/mantis/view.php?id=8481

If you're experiencing this differently, please share a Jing video and debug log to go with the video.

Thanks.

-Rusty

[willyvds]

Rusty,
yes, indeed this happens, exactly! It happens also if I run a MN query that does not give any results.

Note that the "reading files"does not run literally indefinitely, it just takes quit a long time but does come to a correct end.
And the UI is not fully functional, the upper browsers cannot be accessed.
Maybe this helps to find the cause of the problem, in case that is not yet clear.

This slowness disappears after a full clean up of the library, then MN is fast as ever. In our case, a simple restart does not always have this effect.
Or we have a second problem...

Regards, Willy

[willyvds]

First impression of 1442 is very positive, it seems to have solved this issue.
Thanks!
Regards, Willy

[willyvds]

It is not solved. MM doesn't say reading files anymore, but the simple masks is still very, very slow at times. restarting MM does not always solve the problem.

Regards, Willy

[rusty]

Willy,

Can you see if this is replicable in your environment with a clean library (i.e. after you do a fresh scan of your system) since there are some anomalies in your library (the mismatched album artists) that may be triggering this.

Thanks.

-Rusty