Apache High CPU Usage Enable Mod_Status Guide Solution - Find Cause of High CPU Usage Script/Domain
mod_status is a great way to track down the source of high CPU usage and to find what vhost/script is the cause of it.
It gives you a live view of bandwith usage, CPU usage, and memory usage broken down by domain/vhost and script/URI.
Enable mod_status
vi /etc/httpd/conf/httpd.conf
ExtendedStatus On
<Location /server-status>
SetHandler server-status
Order Deny,Allow
Deny from all
Allow from 127.0.0.1
</Location>
Add your IP after 127.0.0.1. I believe you could also require an htaccess pasword if you want.
After that reload Apache and browse to your webserver to http://yourhost.com/server-status and you'll see something like below:
Apache Server Status for localhost
- Server Version: Apache/2.2.3 (CentOS)
- Server Built: Aug 30 2010 12:32:08
Current Time: Saturday, 30-Apr-2011 15:55:46 PDT
- Restart Time: Thursday, 28-Apr-2011 23:03:58 PDT
- Parent Server Generation: 3
- Server uptime: 1 day 16 hours 51 minutes 48 seconds
- Total accesses: 243995 - Total Traffic: 1.7 GB
- CPU Usage: u18.36 s1.75 cu2.88 cs0 - .0156% CPU load
- 1.66 requests/sec - 12.1 kB/second - 7.3 kB/request
- 1 requests currently being processed, 3 idle workers
W_..__....
Scoreboard Key:
"_" Waiting for Connection, "S" Starting up, "R" Reading Request,
"W" Sending Reply, "K" Keepalive (read), "D" DNS Lookup,
"C" Closing connection, "L" Logging, "G" Gracefully finishing,
"I" Idle cleanup of worker, "." Open slot with no current process
| Srv | PID | Acc | M | CPU | SS | Req | Conn | Child | Slot | Client | VHost | Request |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 0-3 | 22481 | 0/29/36628 | W | 0.42 | 0 | 0 | 0.0 | 0.04 | 307.98 | 9 | testdomain.com | GET /server-status?refresh=10 HTTP/1.1 |
| 1-3 | 18115 | 0/271/37239 | _ | 6.33 | 4 | 236 | 0.0 | 1.20 | 255.47 | forums.testdomain.com | POST /mgc_cb_evo_ajax.php HTTP/1.1 | |
| 2-3 | - | 0/0/35305 | . | 0.61 | 54 | 0 | 0.0 | 0.00 | 235.80 | forums.testdomain.com | GET /forumdisplay.php?s=e5pr | |
| 3-3 | - | 0/0/34526 | . | 9.19 | 69 | 0 | 0.0 | 0.00 | 235.66 | ::1 | 00-defaultsite.com | OPTIONS * HTTP/1.0 |
| 4-3 | 22258 | 0/49/28952 | _ | 1.12 | 4 | 0 | 0.0 | 0.21 | 194.55 | forums.testdomain.com | GET /cpstyles/kartel/kartel/misc/down9x9.gif HTTP/1.1 | |
| 5-3 | 19843 | 0/232/27942 | _ | 3.10 | 1 | 137 | 0.0 | 0.77 | 181.58 | unitetest.com | GET //index.php?action=profile;u=174 HTTP/1.1 | |
| 6-3 | - | 0/0/19301 | . | 2.31 | 569 | 0 | 0.0 | 0.00 | 130.28 | ::1 | 00-defaultsite.com | OPTIONS * HTTP/1.0 |
| 7-3 | - | 0/0/16325 | . | 0.26 | 2102 | 0 | 0.0 | 0.00 | 141.16 | ::1 | 00-defaultsite.com | OPTIONS * HTTP/1.0 |
| 8-3 | - | 0/0/5534 | . | 0.01 | 2103 | 0 | 0.0 | 0.00 | 36.51 | ::1 | 00-defaultsite.com | OPTIONS * HTTP/1.0 |
| 9-3 | - | 0/0/2243 | . | 0.09 | 2100 | 0 | 0.0 | 0.00 | 15.39 | ::1 | 00-defaultsite.com | OPTIONS * HTTP/1.0 |
| Srv | Child Server number - generation |
|---|---|
| PID | OS process ID |
| Acc | Number of accesses this connection / this child / this slot |
| M | Mode of operation |
| CPU | CPU usage, number of seconds |
| SS | Seconds since beginning of most recent request |
| Req | Milliseconds required to process most recent request |
| Conn | Kilobytes transferred this connection |
| Child | Megabytes transferred this child |
| Slot | Total megabytes transferred this slot |
| SSL/TLS Session Cache Status: |
| cache type: SHMCB, shared memory: 512000 bytes, current sessions: 3 sub-caches: 32, indexes per sub-cache: 133 time left on oldest entries' SSL sessions: avg: 6 seconds, (range: 6...7) index usage: 0%, cache usage: 0% total sessions stored since starting: 571 total sessions expired since starting: 568 total (pre-expiry) sessions scrolled out of the cache: 0 total retrieves since starting: 15093 hit, 512 miss total removes since starting: 0 hit, 0 miss |
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