Bug #60274 [Fbk->Asn]: cpu steady on httpd processes never clears
| From: | jwprice at georgiasouthern dot edu | Date: | Wed, 29 Feb 2012 13:42:44 +0000 |
| Subject: | Bug #60274 [Fbk->Asn]: cpu steady on httpd processes never clears | ||
| References: | 1 | Groups: | php.bugs |
| Request: | Send a blank email to php-bugs+get-167941@lists.php.net to get a copy of this message | ||
Edit report at https://bugs.php.net/bug.php?id=60274&edit=1
ID: 60274
User updated by: jwprice at georgiasouthern dot edu
Reported by: jwprice at georgiasouthern dot edu
Summary: cpu steady on httpd processes never clears
-Status: Feedback
+Status: Assigned
Type: Bug
Package: OCI8 related
Operating System: Solaris 10
PHP Version: 5.3.8
Assigned To: sixd
Block user comment: N
Private report: N
New Comment:
What do you mean by httpd process cycled? Do you be restarted every so often?
I was not aware there were and php.ini oci settings so we're using whatever the
defaults are. The database is on a separate machine.
These settings have been set for a couple of years now. We changed MaxClients to
1200 an it solved couple of problems we were having and worked for one fall registration. We only
started having a problem when we upgraded php and apache
from php 5.2.11 and apache 2.0.63
<IfModule prefork.c>
ServerLimit 1200
StartServers 5
MinSpareServers 5
MaxSpareServers 10
MaxClients 1200
MaxRequestsPerChild 5000
</IfModule>
Previous Comments:
------------------------------------------------------------------------
[2012-02-29 00:09:59] sixd@php.net
Are the httpd processes not being cycled by choice? What are the MaxClients and
MaxRequestsPerChild values? (Are you using the prefork MPM?).
What are the php.ini oci8.* values?
Is the DB on a different host?
oci_pconnect will cause DB host memory contention unless you restrict MaXClients
and/or have Oracle 11g and use its DRCP.
------------------------------------------------------------------------
[2012-02-28 19:46:39] jwprice at georgiasouthern dot edu
cpu load was measured with uptime and prstat. Note this is a 4 core 16 thread
16Gb SunFire T2000. Load is normally between 3 and 5, between 350 and 550
process. During the busy time load was > 200 and stayed there even after the
load on the database was gone. I would say that the httpd processes were
spinning at 3 to 4% of cpu each normally this is a lot lower .1%. They are not
being cycled. We are using an older version of the oracle client we will
definitely try to update it. We have since updated to apache 2.2.21 and php-
5.3.8. We will have another high load Mar 5th. We've stayed away from
persistent connections because it caused a high load on the database. We will
look into the performance tips you mentioned.
Apache was configured and compiled with the following:
./configure --enable-modules=most \
--prefix=${Home}/server \
--enable-mods-shared=most \
--enable-proxy \
--enable-proxy-http \
--enable-so
------------------------------------------------------------------------
[2012-02-28 18:39:15] sixd@php.net
This bug just came to my attention and I've now changed the package from
"Performance" to "OCI8".
How are you measuring CPU load? How is Apache configured and what is the system
configuration? Are httpd process spinning? Are they being cycled? 600 processes
seems a large number for a single commodity machine. One old rule of thumb was
to set maxclients to 25 for a 1Gb, 2-core machine. Look at reducing maxclients
and using persistent OCI8 connections. If possible, use Oracle 11g DRCP
connections.
I'd recommend upgrading the Oracle client by using the free Oracle Instant
Client. Use the latest version that can still connect back to your DB.
The current PHP OCI8 hasn't had any particularly relevant changes since 5.3.4.
Make sure the code uses binds, prefetches, etc. effectively. Check the
performance tips in
http://www.oracle.com/technetwork/topics/php/underground-php-oracle-manual-
098250.html
------------------------------------------------------------------------
[2011-11-11 21:21:27] jwprice at georgiasouthern dot edu
Description:
------------
During a busy time over 600 httpd processes on the webserver and oracle database
cpu load over 88. The cpu load on each httpd process climbs to 3 and 4 % over
loading our server forcing cpuloads of > 200 on the webserver. After load on the
database clears usually in about 15 min, the httpd process never clear their cpu
usage even after a week of no activity. The cpu load on the httpd processes
usally ranges from .4 to 0%. The cpu load problem on the webserver is definitely
related to slowness on the oracle database side, but what concerns me is the
apache server never clears itself. I suspect there is some issue with the oci
functionality.
I'm reporting this before upgrading to the latest version because i don't see
any fixes related. We are using php version 5.3.4. Configure script below.
Home=/portal
ApacheStdName=httpd-
ApacheVer=2.2.17
PHPVer=5.3.4
PHPStdName=php-
OracleClientHome=/oraclient/ora920
MysqlHome=/usr/local/mysql
ModSSLStdName=mod_ssl-
ModSSLVer=2.8.22-1.3.33
cd ${Home}/${PHPStdName}${PHPVer}
./configure \
--prefix=${Home}/local \
--with-apxs2=${Home}/server/bin/apxs \
--with-gettext \
--enable-ftp \
--with-openssl=/usr/local/ssl \
--with-mysql=${MysqlHome} \
--with-pear=${HOME}/pear \
--enable-cli \
--disable-cgi \
--with-curl \
--with-mcrypt=/usr/local \
--with-zlib \
--with-zlib-dir=/usr/local \
--with-jpeg-dir=/usr/local \
--with-png-dir=/usr/local \
--with-xpm-dir=/usr/local \
--with-freetype-dir=/usr/local \
--enable-gd-native-ttf \
--with-ttf=/usr/local \
--with-gd \
--with-ldap=/usr/local \
--with-oci8=${OracleClientHome} \
--with-config-file-path=${Home}/etc
Test script:
---------------
We use
oci_connect
------------------------------------------------------------------------
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Edit this bug report at https://bugs.php.net/bug.php?id=60274&edit=1