[Pacemaker] Questions about 2-node cluster with mysql, apache, tomcat and shared partition

Glauber Cabral glauber.sp at gmail.com
Thu Feb 11 10:07:04 EST 2010


Hi people.
I've been reading about cluster for some time and trying to configure
a 2-node cluster with shared storage.
I've already used the IRC channel, but these questions were to big to
ask there and I though the list should be a better place to make these
questions.
I would appreciate a lot if you can help me.

I've created the configuration showed in the end of this message.
I've still not included STONITH and I'm not sure if this is causing problems.
I think the cluster behavior should be like this:
OCFS2: partition with database files and some files that tomcat will
access ( the application guarantees that a file will not be accessed
by both tomcat instances, at least to our needs at the moment).
Mysql: only one node running and accessing datadir inside the shared storage.
Tomcat: both nodes running tomcat and accessing mysql by a virtual IP
apache: will run only on one node and will load balance connections to
both tomcats by ajp protocol.
tomcat needs to start after mysql and filesystem
apache will start after tomcat (but I'm not sure if it's necessary)

The first question if about mysql. It's running only on one node at a
time, but the logfile has a warn message showing that the other mysqld
process cannot run anywehere. I'm not sure if this warn is correct or
if I did something wrong configuring mysql service. Should it be
configured as master/slave? I didn't understand this correctly because
all the tutorials I've found use DRDB and not a shared partition.

Another question is about migrating apache from one node to other.
When I migrate apache, the tomcat service is restarted and I guess it
shouldn't be.
I think it's being restarted because of the colocation rule. Is this
correct? Should I remove that rule?

The third question. I tried to shutdown a node by powering it off, and
the services didn't turned on in the other node. Does it occurred
because I don't have STONITH configured? I know there are few
information here to answer this question, but I just want to have
ideas about what kind of error I must look for.

Thank you in advance for any suggestions and help.
Cheers,
Glauber

The crm configuration:

node erytheia
node panopea
primitive apache ocf:heartbeat:apache \
        params configfile="/etc/httpd/conf/httpd.conf" \
        op monitor interval="1min" \
        meta target-role="Started" is-managed="true"
primitive dlm ocf:pacemaker:controld \
        op monitor interval="120s"
primitive fs ocf:heartbeat:Filesystem \
        params device="/dev/xvdb1" directory="/tidia" fstype="ocfs2" \
        op monitor interval="120s"
primitive ip ocf:heartbeat:IPaddr2 \
        params ip="143.106.157.26" cidr_netmask="25" \
        op monitor interval="30s"
primitive ip_mysql ocf:heartbeat:IPaddr2 \
        params ip="192.168.128.10" cidr_netmask="25" \
        op monitor interval="30s" timeout="30s" start-delay="0" depth="0"
primitive mysqld ocf:heartbeat:mysql \
        params binary="/usr/bin/mysqld_safe"
datadir="/tidia/mysql/datadir" pid="/home/sakai/mysql/mysqld.pid"
socket="/home/sakai/mysql/mysqld.sock"
log="/home/sakai/mysql/mysqld.log" user="sakai" group="tidia" \
        meta target-role="Started" \
        op monitor interval="120s"
primitive o2cb ocf:ocfs2:o2cb \
        op monitor interval="120s"
primitive tomcat ocf:heartbeat:tomcat \
        params statusurl="http://127.0.0.1:8080"
java_home="/usr/java/jdk1.5.0_22" tomcat_name="tomcat"
tomcat_user="sakai" tomcat_stop_timeout="120"
tomcat_start_opts="-server -Xms512m -Xmx1024m -XX:+UseParallelGC
-XX:PermSize=256m -XX:MaxPermSize=512m -XX:NewSize=256m
-XX:MaxNewSize=486m -Djava.awt.headless=true -Duser.language=pt
-Duser.region=BR -Dsakai.demo=false"
catalina_home="/usr/lib/apache-tomcat-5.5.23"
catalina_pid="/usr/lib/apache-tomcat-5.5.23/logs/catalina.pid"
catalina_opts="-Xmx512M -XX:MaxPermSize=256M
-Duser.timezone=America/Sao_Paulo -Duser.language=pt -Duser.region=BR"
\
        op start interval="0" timeout="240s" \
        op stop interval="0" timeout="240s" \
        op status interval="0" timeout="60s" \
        op monitor interval="10s" timeout="30s" start-delay="0" depth="0" \
        meta target-role="Started"
clone dlm-clone dlm \
        meta globally-unique="false" interleave="true" target-role="Started"
clone fs-clone fs \
        meta interleave="true" ordered="true" target-role="Started"
clone mysql-clone mysqld \
        meta interleave="true" target-role="Started"
clone o2cb-clone o2cb \
        meta globally-unique="false" interleave="true" target-role="Started"
clone tomcat-clone tomcat \
        meta ordered="false" interleave="true" globally-unique="false"
is-managed="true"
location cli-prefer-apache apache \
        rule $id="cli-prefer-rule-apache" inf: #uname eq erytheia
location cli-prefer-ip ip \
        rule $id="cli-prefer-rule-ip" inf: #uname eq erytheia
location cli-prefer-mysql-clone mysql-clone \
        rule $id="cli-prefer-rule-mysql-clone" inf: #uname eq erytheia
colocation apache-with-ip inf: apache ip
colocation fs-with-o2cb inf: fs-clone o2cb-clone
colocation mysql_with_fs inf: mysql-clone fs-clone
colocation mysql_with_ip_mysql inf: mysql-clone ip_mysql
colocation o2cb-with-dlm inf: o2cb-clone dlm-clone
colocation tomcat_with_fs inf: tomcat-clone fs-clone
order start-apache-after-ip inf: ip apache
order start-fs-after-o2cb inf: o2cb-clone fs-clone
order start-o2cb-after-dlm inf: dlm-clone o2cb-clone
order start_mysql_after_fs inf: fs-clone mysql-clone
order start_mysql_after_ip_mysql inf: ip_mysql mysql-clone
order start_tomcat_after_fs inf: fs-clone tomcat-clone
order start_tomcat_after_ip inf: ip tomcat-clone
order start_tomcat_before_apache inf: tomcat-clone apache
property $id="cib-bootstrap-options" \
        last-lrm-refresh="1265892279" \
        expected-quorum-votes="2" \
        dc-version="1.0.5-ee19d8e83c2a5d45988f1cee36d334a631d84fc7" \
        cluster-infrastructure="openais" \
        stonith-enabled="false" \
        no-quorum-policy="ignore"
rsc_defaults $id="rsc-options" \
        resource-stickiness="100"




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