vBulletin + Tapatalk not working on Litespeed Enterprise v4.0.18

[Bossman]

Hello,

We have just installed the trial version of Litespeed Web Server Enterprise v4.0.18 on our forums, but despite the obvious increase in performance, it seems to have broken the vBulletin Tapatalk plugin used by our iPhone / HTC users.

Basically, the installation verifier from the Tapatalk site gives the following error:

"Not Installed: Cannot detect /mobiquo/mobiquo.php. Check this file existence and try again."

And sure enough, the direct link to said php file gives a 404 Page, even though it is there where it should be. The weird part is that a .js file (tapatalkdetect.js) located in the same folder can be accessed without issues

There were no changes made to the htaccess file, firewall or folder structure when we switched from Apache to Litespeed, so the only conclusion we've drawn is that there's something in the Litespeed config which is "blocking" the access.

Any suggestions on how we could solve this particular issue would be very appreciated.

[NiteWave]

please compare the phpinfo() in litespeed and apache if any difference.

google "mobiquo/mobiquo.php", there are a lot same error reports. here's one:
http://tapa.tk/forum/showthread.php?t=4599

it should not be a litespeed specific issue at all.

[Bossman]

We know about the common errors with mobiquo, but the plugin was working fine with Apache for months up until the switch, and as I've already said

There were no changes made to the htaccess file, firewall or folder structure when we switched from Apache to Litespeed

So that either leaves the PHP (which we will check) or the httpd server.

[NiteWave]

so the question may be at "Building matching PHP" and I asked you to compare the output of phpinfo() under apache and litespeed. What's the environment and how did you build lsphp5 to match apache PHP.

[Bossman]

Ironically, it wasn't the PHP or Litespeed, but a meager owner permission on the docroot. My apologies for not thoroughly verifying everything before pointing fingers.

On a related note, we keep getting quite a number of "Failed to initialize VMemBuf." errors in our logs, and the users have complained that on occassion, when they try to open an attachment, they would get a 503 error.

Any particular tuning settings we should be aware of?

The machine sports an Intel Xeon E5420 (2.5Ghz) with 16GB Ram, Raid1 for the filesystem / vbulletin php files and Raid10 for attachments.

[NiteWave]

Thanks for the update. so the initial issue has gone?

when they try to open an attachment, they would get a 503 error

is the attachment big? there are many reasons which cause 503 error. no enough memory is one of them. what's "Memory Soft/Hard Limit" of your lsphp5 process?

[Bossman]

450M for the Soft Limit, 500M for Hard

The maximum size for an attachment is 4.8MB, usually images.

[NiteWave]

please try increase to 700M/750M, see if difference.

[Bossman]

It alleviated the problem to a certain degree, but users still get the 503 error from time to time.

[NiteWave]

please check the related log message in error_log(or error.log) and stderr.log