Eaccelerator - Very high load - blank pages -URGENT

Eaccelerator - Very high load - blank pages -URGENT

by A. H. -
Number of replies: 4
Hello,

load on the server is high and cpus are always 99%!!!

On 165, i had eaccelerator running and it was great.
Whats wrong with 184?!

This is my php5.2.1 configuration:
'./configure' '--with-apxs2=/usr/local/apache2/bin/apxs' '--build=i386-redhat-linux' '--host=i386-redhat-linux' '--target=i386-redhat-linux-gnu' '--program-prefix=' '--prefix=/usr' '--exec-prefix=/usr' '--bindir=/usr/bin' '--sbindir=/usr/sbin' '--sysconfdir=/etc' '--datadir=/usr/share' '--includedir=/usr/include' '--libdir=/usr/lib' '--libexecdir=/usr/libexec' '--localstatedir=/var' '--sharedstatedir=/usr/com' '--mandir=/usr/share/man' '--infodir=/usr/share/info' '--cache-file=../config.cache' '--with-config-file-path=/etc' '--with-config-file-scan-dir=/etc/php.d' '--enable-force-cgi-redirect' '--disable-debug' '--enable-pic' '--disable-rpath' '--enable-inline-optimization' '--with-bz2' '--with-db4=/usr' '--with-curl' '--with-exec-dir=/usr/bin' '--with-freetype-dir' '--with-png-dir=/usr' '--with-gd' '--enable-gd-native-ttf' '--without-gdbm' '--with-gettext' '--with-ncurses' '--with-gmp' '--with-iconv' '--with-jpeg-dir=/usr' '--with-openssl' '--with-png' '--with-aspell' '--with-xml' '--with-expat-dir=/usr' '--with-dom' '--with-dom-xslt=/usr' '--with-dom-exslt=/usr' '--with-xmlrpc' '--with-zlib' '--with-layout=GNU' '--enable-bcmath' '--enable-exif' '--enable-ftp' '--enable-magic-quotes' '--enable-sockets' '--enable-sysvsem' '--enable-sysvshm' '--enable-track-vars' '--enable-trans-sid' '--enable-yp' '--enable-wddx' '--with-pear=/usr/share/pear' '--with-imap=../imap-2004c1' '--with-kerberos' '--with-ldap' '--with-mysql' '--enable-memory-limit' '--enable-shmop' '--enable-calendar' '--enable-dbx' '--enable-dio' '--enable-mbstring' '--enable-mbstr-enc-trans' '--enable-mbregex' '--with-mime-magic=/usr/share/file/magic.mime'

this is the eaccelerator configuration i used:
./configure --enable-eaccelerator=shared --with-php-config=/usr/bin/php-config --with-eaccelerator-shared-memory --with-eaccelerator-sessions --with-eaccelerator-content-caching

still when i enable rcache, i get a blank page!
PLUS, the load is extremely high.
Same machine which hosted 165 had the load between 0 and 1.
Load of 1.5 when around 200 users taking a quiz at the same time!

NOW, the load is between 4 and 5 for couple of users connected!!!Thats a similar load to what i used to see before installing eaccelerator for moodle 165.

Thats all coz Moodle cant recognize or work with eaccelerator! What do i need to change / do?

thnx,
amer
Average of ratings: -
In reply to A. H.

Re: Eaccelerator - Very high load - blank pages -URGENT

by Marcus Green -
Picture of Core developers Picture of Particularly helpful Moodlers Picture of Plugin developers Picture of Testers

If eaccelerator is a php accellerator and Moodle runs PHP then Moodle will benefit from any improvement in PHP performance. What operating system are you using (some kind of Linux I suspect) and what is the output from the top command (gives information about the resource usage of processes).

Solving these types of problems is often a case of step by step elimination of potential causes, which can be difficult because the cause can be so wide. Good luck.

In reply to Marcus Green

Re: Eaccelerator - Very high load - blank pages -URGENT

by A. H. -
But why am i getting the blank pages when i use rcache? doesnt it mean that moodle might not be using the eaccelerator?what is missing in my configs thats causing this problem?

In reply to A. H.

Re: Eaccelerator - Very high load - blank pages -URGENT

by Martin Dougiamas -
Picture of Core developers Picture of Documentation writers Picture of Moodle HQ Picture of Particularly helpful Moodlers Picture of Plugin developers Picture of Testers
Turn off "cachetype" (set it to internal) in the Moodle admin settings. You don't need it to take advantage of eaccelerator, and as the info next to that setting says, it can make your site much slower.

Most of what eaccelerator does is works with PHP to cache processed scripts, and Moodle has no say in that.

On top of this, Moodle 1.8.x can take up a little more CPU than 1.6 did (because of new features), depending on your configuration. However Moodle 1.9 (final release is next week) has had a lot of optimisation work and is somewhat faster than 1.8 all around.

I would also make sure query caching is turned on in MySQL and slim down your PHP a lot ... do you really need all those modules taking up your memory?

moodle.org looks like this:

./configure --with-apxs2=/usr/sbin/apxs --enable-mbstring --with-libdir=lib64 --with-mysql=/usr --with-pear --enable-sockets --with-gd --with-jpeg-dir=/usr --with-ttf --with-freetype-dir=/usr --with-zlib-dir=/usr --with-iconv --with-curl --with-openssl --with-mysqli --enable-soap --with-xmlrpc

In reply to Martin Dougiamas

Re: Eaccelerator - Very high load - blank pages -URGENT

by A. H. -
Hello Martin,

I really appreciate your reply and your clear explanation. It gave me a sigh of relief, a bit smile.

1- The server is only hosting Moodle, so all the unwanted php modules can be removed.

2- Eaccelerator:
it is running on the system but not recognized by moodle. However, i was worried about this issue coz all forums talk about how eaccelerator improved performance.

2.1- So according to your advice, Internal should work fine with the case below too?

2.2 - If i understood correctly, eaccelerator might still be working even if i didnt select it from cachetype?(coz 165 didnt have this option to select and it was working)

3- Query caching is on

4- My performance concern comes when i face the case below:


Re-explaining in details our technique so maybe it helps others who use quizzes with huge number of students
Moodle 165 quizzes + eaccelerator:
250+ students used to take a quiz at the same time,
every 30 student starts 1 min later than the previous group.
The quiz questions are divided to 5 per page.
It worked PERFECT and load was MAX 1.5.

Before eaccelerator and before the conditions we put (dividing questions and students), server used to get to a halt at the end of the quiz.


Now, we are all worried here about Quizzes in Moodle 1.8.4 and we can not upgrade while semester is running. And frankly, Moodle on campus got widely known mainly coz if its quiz module.

(P.S.: backup for 600 course is taking around 50 hours whereas 165 used to take 8 hours)

Thank you for any further advice.
amer