1-2 minute no response from server

[webizen]

You can order 1 hour support when issue arises.

[inxile]

Here is a set of stats when an issue arose:


Here is the monitoring stats:

kbmemfree kbmemused %memused kbbuffers kbcached kbswpfree kbswpused %swpused kbswpcad
01:00:01 PM 3109568 1038472 25.04 23304 635420 1995456 101016 4.82 23360
01:05:01 PM 3289428 858612 20.70 28836 532984 1995500 100972 4.82 23688
01:10:09 PM 152268 3995772 96.33 10612 1402236 1499320 597152 28.48 46508
01:15:08 PM 175720 3972320 95.76 14028 1198712 796212 1300260 62.02 338488
01:20:08 PM 410212 3737828 90.11 14292 1149120 813132 1283340 61.21 283320

What config settings would be best to adjust when in this kind of scenario?

[inxile]

We've been making a number of corrections and tweaks to the system and things have gotten better.

However, we continue to experience a complete hang of the system from time to time... about 15-20 minutes or half hour or so. The website times out and is unresponsive for about a minute, then all is fine.

During this time we see the following:

EAProc WaitQ is in the mid 100's
EAProc In Use is less than 10
Req in Processing is slightly higher than EAProc WaitQ, mid 100's

It appears settings are throttled a little to tight, what settings should I be looking to to adjust to relieve the EAProc WaitQ?

Follow Up: Logs are stating the PHP suEXEC Max Conn 512 is invalid and are defaulting to 5. What are valid values?

[webizen]

PHP suEXEC Max Conn sets to 5-10 normally.

You should adjust Max Connections in lsphp5 (in External App): bump it up by 50 at a time (environment variable PHP_LSAPI_CHILDREN needs to be set the same as Max Connections).

[inxile]

Currently,

General >>
PHP suEXEC Max Conn: 499

lsphp5 >>
Max Connections: 20
PHP_LSAPI_MAX_REQUESTS=256
PHP_LSAPI_CHILDREN=20

[webizen]

change to following to begin with:

General >>
PHP suEXEC Max Conn: 10

lsphp5 >>
Max Connections: 50
PHP_LSAPI_MAX_REQUESTS=512
PHP_LSAPI_CHILDREN=50

[inxile]

After about 10 minutes it happened again... a spike in WaitQ and site was unresponsive. I upped the max conn and PHP_LSAPI_CHILDREN to 100 and restarted. Took a minute for the WaitQ to die down again. Now 5 minutes later its tapped out again.

We average about 10 million hits a month.

[webizen]

try PHP suEXEC Max Conn: 10 => 200.

BTW, what's your server config (OS, RAM size, etc)?

[inxile]

2 7200 RPM 1 TB hard disks in a RAID-1 array, with a 3Ware 9650SE-2LP RAID controller
8 GB of RAM
Intel Core 2 Quad Q6600

Litespeed Web Server Enterprise v4.0.20
CentOS and PHP were recently updated to current

[mistwang]

It is likely a slow SQL query or something else blocked all PHP processed, increasing "max connections" wont work.
You need to find out what happened from command line, check "top" output for CPU utilization, I/O wait, load, memory usage, etc.
Check mysql slow query cache, check "mysqladmin processlist" .
Also, check "dmesg" output.