Connections to PHP LSAPI socket timing out under higher traffic

[eek]

Hi there,

we are running version 3.3.14 with LSAPI php (php version: 4.4.9, LSAPI version: 4.1) we are hostin approximately 280 php domains and couple of rails applications (5 I think of which 3 are being frequented more) on a 2-CPU box with 4GB of RAM. Recently we started to run into connection timeouts to the lsapi php socket:

2009-12-20 13:35:34.066 [INFO] [65.55.106.210:48960-0#APVH_***:80] connection to [uds://tmp/lshttpd/global-php.sock] on request #24, error: Connection timed out!

and connection resets

2010-01-28 09:26:42.014 [INFO] [12.32.232.44:11879-0#APVH_***:80] connection to [uds://tmp/lshttpd/global-php.sock] on request #13, error: Connection reset by peer!

Connection timeouts are occurring only during high traffic, connection resets are present all the time. By high traffic I mean 100 concurrent connections.

Could you please shed some light into how we could improve things so we wouldn't get into connection timeouts so easily?

I am including some configuration:

General

Priority:15
Memory I/O Buffer:1G

Tuning/Connection

Max Connections: 200
Max SSL Connections: 100
Connection Timeout (secs): 300
Max Keep-Alive Requests: 20
Smart Keep-Alive: Yes
Keep-Alive Timeout (secs): 5
Send Buffer Size (bytes): 0
Receive Buffer Size (bytes): 0

Security/External Application Resource

CPU Soft Limit (sec):300
CPU Hard Limit (sec):600
Memory Soft Limit (bytes):500M
Memory Hard Limit (bytes):600M
Process Soft Limit:50
Process Hard Limit:50

LSAPI PHP

Name	: global-php
Address: uds://tmp/lshttpd/global-php.sock
Notes	: Not Set
Max Connections: 200
Environment: LSAPI_CHILDREN=200, LSAPI_MAX_REQS=100, LSAPI_MAX_IDLE=20, LSAPI_MAX_IDLE_CHILDREN=1
Initial Request Timeout (secs): 300
Retry Timeout (secs): 0
Persistent Connection: Yes
Connection Keepalive Timeout: 5
Response Buffering: No
Auto Start: Yes
Command: $SERVER_ROOT/fcgi-bin/lsphp
Back Log: 100
Instances: 1
Run On Start Up: Yes
Max Idle Time: 20
Priority: Not Set
Memory Soft Limit (bytes): 300M
Memory Hard Limit (bytes): 500M
Process Soft Limit: 80
Process Hard Limit: 100

Thank you!

 

[mistwang]

time to upgrade to latest LSWS 4.0.12 with latest LSAPI.

 

[eek]

Thanks for the reply, but besides the upgrade (I haven't found any mention of this behavior in the server release log), do you have any additional advice regarding the configuration that would help reduce these connection problems?

Thank you!

Andrej

 

[mistwang]

You should increase

Memory Soft Limit (bytes): 500M
Memory Hard Limit (bytes): 600M
Process Soft Limit: 800
Process Hard Limit: 1000

 

[anewday]

I thought those log entries are normal.

LSAPI_MAX_REQS=100

Could it be due to the above?

 

[eek]

We found another interesting fact. LSAPI PHP processes are having quite high disk I/O. Most of the I/O actions was dirtying nodes, but what puzzled me a bit was that there were static files (mostly pictures) being touched by LSAPI PHP process. That brings me to a question are we serving static files through LSAPI PHP ? That shouldn't be the case since only .php suffix is setup to be handled by LSAPI PHP.

Just to clarify we are using PLESK and Litespeed as a replacement for Apache. Is there a need for rewrite rules in order to not serve static content through php process?

All other files referenced by the I/O activity were .php files. That brings me to another question. Would this activity lower if we used opcode cache ?

Thank you!

I thought those log entries are normal.

LSAPI_MAX_REQS=100

Could it be due to the above?

Yes I would imagine that Connection Resets are being caused by the request limit. I am more concerned about the Connection Timeouts.

Andrej

 

[NiteWave]

That brings me to a question are we serving static files through LSAPI PHP ?

should not. how do you come to this conclusion?

have you upgraded to 4.0.12, or still be 3.3.24?

LSAPI_MAX_REQS=100

looks too small. how about 1000, 5000?