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

[Andrew Beekhof]

On Thu, Feb 11, 2010 at 4:07 PM, Glauber Cabral <glauber.sp at gmail.com> wrote:
> 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,

You cloned it though, so it thinks it should be able to run more than once.

> 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?

If they're supposed to run on both hosts with one of them r/o and
syncing from the other, yes.

> 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?

Probably not.
You should create a hb_report for that.

>
> 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?

No, its because they're already there.  You cloned them all, they're
always running there.
Although OCFS2 with no STONITH is insanely dangerous.

> 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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