Our forums (www.PianoWorld.com/forum) have been acting up the last couple weeks. Seems to be even worse over the last couple days.

Members/visitors are encountering this message:

UBB Message
We encountered a problem. The reason reported was
Database error only visible to forum administrators

Please click back to return to the previous page.

Or, it's taking unusually long to load a page.
There is even a thread running about the issues:
http://www.pianoworld.com/forum/ubbthreads.php/topics/1237272

We are running on multiple Sun Machines with tons of ram.
The techs at our hosting service have allocated lots of memory , processing power, and SQL connections to the forums.

I'm not technical enough to know where to look or what might be causing the issues.

If anyone can help, I'd appreciate it.
I'm even willing to pay for some expertise. The forums are an important part of my site.

Well, your best bet is to turn on MySQL error logging and asking users to write down that time (and their timezone) that an error occoured, then you can look at the error log and see what the error is at that time.

The message is displayed as to not show users queries/data/passwords that may be bad to display as plain text...

Sounds like your not able to connect to the database.

Thanks, I just enabled the sql error logging.

Of course that presumes I'll have any idea what it means if it logs any errors.

Not nessessarily, there are plenty of reasons why an error would be triggered, such as not sending the forum id variable with request; there are plenty of reasons that the errors popup; just search around and you can find quite a few ...

Well, you tell us what the logs say, we'll tell you how to fix it .

So I turned on error logging (and tested the directory).

People are still getting the message...

"UBB Message
We encountered a problem. The reason reported was
Database error only visible to forum administrators

Please click back to return to the previous page."

Either that, or they get really sloooow loading pages.

Nothing has showed up in the error log directory (except the test file).

Arggh.

In the meantime, I've had the admin at our hosting service checking things on his end. He has some technical questions that may help, he is going to join the threads forum.
His name is Ken Chase, from heavycomputing.ca. Good guy, knows his stuff.
I would appreciate whatever you folks could do to help him (and me) out.

Hi, Im the admin of the system in question that pianoworld is referring to.

During a system backup, there's a fair bit of file IO going on, and of course the forums are still up and running as usual. If there's alot of activity (say a few forum searches in the large forum system), things can get very heavily loaded and slow for short periods of time. Sometimes however, it seems to stop completely.

I watched this happen today, and so stopped the backup, checked for anything else on the server using IO and killed it, and the system was completely idle. The main website (outside UBB) was peppy, and mysql on the cmd line for even complex queries was very fast. However the forums were still not working, generating that error.

Only after stopping and restarting apache and mysql did things recover. (Im thinking stopping mysql didnt do anything, it was apache). My guess is there's a connection pool to mysql that UBB uses and it got filled with a number of requests that wedged while the server was busy for a short period, but then all other queries piled up behind.

The most curious thing is that this has been happening off and on for the last few weeks, but the system eventually recovers. Im wondering how it does, and when - what's it waiting for when the system is already idle for several minutes before it recovers? I dont see any crontabs installed that would do some regular 'cleanup' operation... So what's causing it to unwedge, and why doesn't it happen faster once load dissipates?

(Obviously this connection pooling is my personal theory with no evidence, just have seen it with other applications in the past - wondering what I should do/run/look at to verify that's what's happening.)

Thanks.

-math

Well, if it's not writing errors to the disk, you could set the "$showerror = 0;" line in /libs/mysql.inc.php to "$showerror = 1;" and it'll just dump the error to the user's browser... But again, at times, it's possible that it could contain data that you otherwise wouldn't want people to see.

Thanks Gizmo, but I'm a little hesitant to open things up that way.

Does anyone know the answers to math's questions above?

It probably would be best to open a support ticket with UBB.
You have logging turned on so if you see that generic database error it should be creating error logs. You can test it by opening control panel>Database tools -SQL COMMAND and submit a bogus query. It will create a error log entry. So I don't understand why you don't have any logs.
As far as mathx stated there are requirements for the connection pool. Can't find it now but I think 50 is the minimum suggested here.