Configure LSAPI

[scott]

lsapi_backend_children

[antoniovilela]

Hi,

How should LSAPI be configured? There is no helpfull information about mod_LSAPI fine tunning.

For instance, lsapi_backend_children, which is probably the most important setting, should be set to which value?

Thanks,

[bogdan.sh]

Hi,

You may want to check our webinar about mod_lsapi, recording is available at https://youtu.be/JUJgozjXtlI

Please also check the following draft explanation image about lsapi_backend_children. In short that is a number of child lsphp processes that will be used for single VirtualHost:

http://kb.cloudlinux.com/wp-content/uploads/2017/01/Screenshot_20161018_163843.png

[antoniovilela]

Hi Bogdan,

Thanks for your answer.

We are experiencing the following error on long or complex php scripts:
503 Service Temporarily Unavailable
The server is temporarily unable to service your request due to maintenance downtime or capacity problems. Please try again later.
Additionally, a 404 Not Found error was encountered while trying to use an ErrorDocument to handle the request.

In apache error log we found:
[Mon Jan 02 18:27:04.548986 2017] [lsapi:error] [pid 911621:tid 140130488612608] [client 213.63.137.202:54421] [host formacao.mcdonalds.pt] Error receiving response: ReceiveResponse: receive pkg hdr failed: ReceivePkgHdr: nothing to read from backend socket, referer: XXXXX/admin/index.php?cache=0&lang=pt&agreelicense=1

[Mon Jan 02 18:36:00.395347 2017] [lsapi:error] [pid 918378:tid 140130555754240] [client 213.63.137.202:54551] [host formacao.mcdonalds.pt] Error receiving response: ReceiveResponse: receive pkg hdr failed: ReceivePkgHdr: nothing to read from backend socket, referer: XXXXXadmin/index.php?cache=0&agreelicense=1&confirmrelease=1& lang=pt

[Mon Jan 02 18:43:11.768783 2017] [lsapi:error] [pid 924293:tid 140130747733760] [client 213.63.137.202:54655] [host formacao.mcdonalds.pt] Error receiving response: ReceiveResponse: receive pkg hdr failed: ReceivePkgHdr: nothing to read from backend socket, referer: XXXXXXXX/admin/index.php?cache=0&agreelicense=1&confirmrelease=1& lang=PT

Do you have a clue if this is a mod_lsapi problem?

Thanks

[antoniovilela]

Hi Bogdan,

Other issue. OpCache resets when we stop using the site for a few seconds.

Is this related to the lsapi_terminate_backends_on_exit option? Should it be Off to keep OpCache alive?

Thanks

[bogdan.sh]

About "ReceivePkgHdr: nothing to read from backend socket" - please check for any EP faults for specified LVE. Or for all LVEs, something like:

lveinfo --by-fault ep

They could also be related to "lsapi_terminate_backends_on_exit On" , better to switch it Off and restart apache.

About OpCache - try increasing lsapi_backend_pgrp_max_idle value. You may be interested in CRIU support, so far in beta stage, supports only CL7 and two PHP version 5.6/70 . But looks really promising and will perfectly match your setup.