SID-00870: Attachments Internal Server Error

Status:	Unanswered	TWiki version:	4.0.0	Perl version:	perl v5.10.0
Category:	CategoryAttachments	Server OS:	Debian 4.0	Last update:	15 years ago

Hello, Users of our twiki have been complaining that they can no longer attach files larger then ~60Mb or that they can no longer "manage" existent attachments larger then ~60Mb. Anything smaller then this works fine.

files larger then ~60Mb will eventually fail with the Internal Server Error 500 page.

The only information from the logs related to this error is

"timeout waiting for output from CGI script /var/www/wiki.gameloft.org/twiki/bin/attach"

followed by

"Premature end of script headers: attach"

The premature error I believe is normal due to the previous error The HTTP header is probably not sent because of the previous timeout.

I straced the Apache process and the "/twiki/bin/attach" script and I find no useful information. Stracing the "attach" script does however reveal that it is constantly doing

"read(3, "4zl6\314\250P.\342`\241\316\273#)\213\262\256\217\200~&}\335\235\257`Y\210\315\306\337\26"..., 4096) = 4096 mremap(0xf3926000, 68235264, 68239360, MREMAP_MAYMOVE) = 0xf3926000"

and before crashing it will output the many line like this

"open("/var/www/wiki.gameloft.org/twiki/sessions/cgisess_30ffd8def7171d165d289f8d37ce9d8e", O_RDONLY|O_LARGEFILE) = 4 ioctl(4, SNDCTL_TMR_TIMEBASE or TCGETS, 0xffffcec8) = -1 ENOTTY (Inappropriate ioctl for device)"

I really don't have much more information so what I'm really asking for is for someone who would know of a way to get more debug information out of this that could potentially give me a clue as to what is causing this.

Is there a way I can debug the "twiki/bin/attach" script from the command-line rather then having to pass through Apache? Maybe some info valuable info isn't being properly passed back to Apache before the timeout.

FYI: I'm unable to find the version of the TWiki but its really old. Upgrading is not an option right now. The issue only started happening recently.

Thank you

-- PhilippeJohnston - 2010-06-17

Discussion and Answer

It would help to know the TWiki version. It is indicated in your TWiki.WebHome page.

Did you change something in the TWiki configuration or installed new plugins/add-ons recently? Do you have enough swap space?

-- PeterThoeny - 2010-06-18

I have checked the WebHome page many times but I believe it has been heavily modified over the years that It no longer has the information about the version. I also could not see the version from /twiki/bin/configure

I think its almost safe to say its a very early 4.0.0 version.

As for swap, that isn't the problem. I ran Top while doing "manage" on one of the +60Mb file and it remained pretty stable.

One question though, what does "twiki/bin/attach" really do when doing "manage" I don't understand why the twiki would be taking so much time just to bring up a page with actions to be done with a single file. Is it trying to read its content or something? what would be the use of doing that? I can understand that uploading the file will take time but for managing the file...I'm not sure I understand that.

Thank you

-- PhilippeJohnston - 2010-06-18

Closing this question after more than 30 days of inactivity. Feel free to reopen if needed. Consider engaging one of the TWiki consultants if you need timely help. We invite you to get involved with the community, it is more likely you get community support if you support the open source project!

-- PeterThoeny - 2010-08-02

If you answer a question - or someone answered one of your questions - please remember to edit the page and set the status to answered. The status selector is below the edit box.