[Pacemaker] Mostly STONITH Questions / Seeking Best Practice

Andrew Beekhof andrew at beekhof.net
Tue Sep 4 22:21:42 UTC 2012 

On Tue, Sep 4, 2012 at 2:31 PM, David Morton <davidmorton78 at gmail.com> wrote:
> Afternoon all,
>
> We have a 2 node failover cluster using IBM IMM for STONITH via the
> external/ipmi plugin. We have recently moved from OCFS2 to ext3 for our
> database filesystems due to a bug we discovered, there is only one disk we
> need to have available to both nodes (shared scripts, logs etc) which
> remains as OCFS2.
> All SAN disks are available to both nodes all of the time, although
> obviously only mounted via the appropriate resource group.
>
> I have the following questions around best practice for this type of
> configuration:
> 1) I'm planning on implementing sfex resources (a small LVM volume on the
> same volume group as the data being protected) as an additional safety
> feature along side the existing external/ipmi STONITH control ... is this
> best practice in case the IBM IMM is unavailable or credentials change etc
> and the STONITH is not carried out ?

Lars is probably the best person to ask about sfex.

> 2) Is there any risk to a healthy node if an unhealthy node with a shared
> OCFS2 volume mounted goes down ? Quorum policy is set to ignore. Seems to
> not give any issues but I want to clarify this is the designed behavior.

It depends what you mean by down.
Down from the healthy node's point-of-view doesn't necessarily mean inactive.
The bad node might believe it is the healthy one and attempt to shoot its peer.

> 3) Does a node need its own STONITH resource to be able to self fence

No, Pacemaker doesn't support self-fencing.
Its very hard to let the other node(s) know that fencing was
successful if you're currently turned off.
So the surviving nodes would need to re-fence the bad node anyway.

> or is
> this covered off by internal pacemaker functionality ? ie: We currently use
> location constraints to ensure STONITH resources don't run on themselves as
> per the documentation.

This is good.

> 4) What is the best way to disable STONITH non disruptively for node
> maintenance ? Is it a case of editing the CIB stonith-enabled directive to
> false and stopping the STONITH resources then stopping openais ?

This shouldn't be required as the surviving node knows the maintenance
node shut down cleanly.

> 5) Is there an OCF compliant resource agent script for Derby / JavaDB that
> anyone knows of ?

Not personally.

> We use an old init style script at the moment, I'm afraid
> it will trip us up and STONITH a node on shutdown at some stage.

It can only trigger fencing if stop fails.  But this can happen for
OCF scripts too.

>
> Are there any other considerations to be in a best practice position ? We
> have a window of change coming up and I want to create the best environment
> possible. Please feel free to critique the below configuration as it stands.
>
> Many thanks, Dave.
>
> node server-001
> node server-002
> primitive DERBYDB lsb:derby
> primitive FS_DB_NEWS ocf:heartbeat:Filesystem \
>         params device="/dev/vg_db_news/lv_db_news" directory="/DB_NEWS"
> fstype="ext3" options="acl" \
>         op monitor interval="40s" \
>         op start interval="0" timeout="60" \
>         op stop interval="0" timeout="60" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive FS_DB_FEEDS ocf:heartbeat:Filesystem \
>         params device="/dev/vg_db_feeds/lv_db_feeds" directory="/DB_FEEDS"
> fstype="ext3" options="acl" \
>         op monitor interval="40s" \
>         op start interval="0" timeout="60" \
>         op stop interval="0" timeout="60" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive FS_DB_SHARED ocf:heartbeat:Filesystem \
>         params device="/dev/mapper/07ea2ffab5c4ae011_part1"
> directory="/DB_SHARED" fstype="ocfs2" options="acl" \
>         op monitor interval="40s" \
>         op start interval="0" timeout="60" \
>         op stop interval="0" timeout="60" \
>         meta target-role="Started"
> primitive FS_LOGS_NEWS ocf:heartbeat:Filesystem \
>         params device="/dev/mapper/0c2ebc3735c4ae011_part1"
> directory="/LOGS_NEWS" fstype="ext3" options="data=writeback,noatime,acl" \
>         op monitor interval="40s" \
>         op start interval="0" timeout="60" \
>         op stop interval="0" timeout="60" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive FS_LOGS_FEEDS ocf:heartbeat:Filesystem \
>         params device="/dev/mapper/0345899885c4ae011_part1"
> directory="/LOGS_FEEDS" fstype="ext3" options="data=writeback,noatime,acl" \
>         op monitor interval="40s" \
>         op start interval="0" timeout="60" \
>         op stop interval="0" timeout="60" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive IP_NEWS_15 ocf:heartbeat:IPaddr2 \
>         params ip="192.168.15.92" cidr_netmask="24" \
>         op monitor interval="30s" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive IP_NEWS_72 ocf:heartbeat:IPaddr2 \
>         params ip="192.168.72.92" cidr_netmask="24" \
>         op monitor interval="30s" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive IP_FEEDS_15 ocf:heartbeat:IPaddr2 \
>         params ip="192.168.15.93" cidr_netmask="24" \
>         op monitor interval="30s" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive IP_FEEDS_72 ocf:heartbeat:IPaddr2 \
>         params ip="192.168.72.93" cidr_netmask="24" \
>         op monitor interval="30s" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive MAIL_ALERT ocf:heartbeat:MailTo \
>         params email="theguy at thatcompany.com" \
>         op monitor interval="60" timeout="10"
> primitive PGSQL_FEEDS1 ocf:heartbeat:pgsql \
>         params pgdata="/DB_FEEDS/feeds1/dbdata/data/" pgport="5432"
> pgdba="feeds1" \
>         op start interval="0" timeout="120" \
>         op stop interval="0" timeout="120" \
>         op monitor interval="60" timeout="30" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive PGSQL_FEEDS2 ocf:heartbeat:pgsql \
>         params pgdata="/DB_FEEDS/feeds2/dbdata/data/" pgport="5434"
> pgdba="feeds2" \
>         op start interval="0" timeout="120" \
>         op stop interval="0" timeout="120" \
>         op monitor interval="60" timeout="30" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive PGSQL_NEWS ocf:heartbeat:pgsql \
>         params pgdata="/DB_NEWS/news/dbdata/data/" pgport="5433"
> pgdba="news" \
>         op start interval="0" timeout="120" \
>         op stop interval="0" timeout="120" \
>         op monitor interval="60" timeout="30" \
>         meta migration-threshold="3" failure-timeout="180"
> primitive STONITH-DB-001 stonith:external/ipmi \
>         params hostname="server-001" ipaddr="192.168.72.80" userid="user"
> passwd="password" interface="lan" \
>         op monitor interval="60s" timeout="30s" \
>         meta target-role="Started"
> primitive STONITH-DB-002 stonith:external/ipmi \
>         params hostname="server-002" ipaddr="192.168.72.81" userid="user"
> passwd="password" interface="lan" \
>         op monitor interval="60s" timeout="30s" \
>         meta target-role="Started"
> primitive VG_DB_NEWS ocf:heartbeat:LVM \
>         params volgrpname="vg_db_news" \
>         op monitor interval="60" timeout="60"
> primitive VG_DB_FEEDS ocf:heartbeat:LVM \
>         params volgrpname="vg_db_feeds" \
>         op monitor interval="60" timeout="60"
> primitive clvm ocf:lvm2:clvmd \
>         params daemon_timeout="30" \
>         op start interval="0" timeout="90" \
>         op stop interval="0" timeout="100"
> primitive dlm ocf:pacemaker:controld \
>         op monitor interval="60" timeout="60"
> primitive o2cb ocf:ocfs2:o2cb \
>         op monitor interval="60" timeout="60"
> group NEWS VG_DB_NEWS FS_LOGS_NEWS FS_DB_NEWS IP_NEWS_15 IP_NEWS_72 DERBYDB
> PGSQL_NEWS \
>         meta target-role="Started"
> group FEEDS VG_DB_FEEDS FS_LOGS_FEEDS FS_DB_FEEDS IP_FEEDS_15 IP_FEEDS_72
> PGSQL_FEEDS1 PGSQL_FEEDS2 \
>         meta target-role="Started"
> group OCFS2_SHARED dlm o2cb clvm FS_DB_SHARED
> clone CL_MAIL_ALERT MAIL_ALERT
> clone CL_OCFS2_SHARED OCFS2_SHARED \
>         meta interleave="true"
> location LOC_NEWS NEWS 25: server-001
> location LOC_FEEDS FEEDS 25: server-002
> location LOC_STONITH-001 STONITH-DB-001 -inf: server-001
> location LOC_STONITH-002 STONITH-DB-002 -inf: server-002
> colocation COL_DB_SHARED_NEWS inf: NEWS CL_OCFS2_SHARED
> colocation COL_DB_SHARED_FEEDS inf: FEEDS CL_OCFS2_SHARED
> order DB_SHARE_FIRST_NEWS 0: CL_OCFS2_SHARED NEWS
> order DB_SHARE_FIRST_FEEDS 0: CL_OCFS2_SHARED FEEDS
> property $id="cib-bootstrap-options" \
>         dc-version="1.1.5-5bd2b9154d7d9f86d7f56fe0a74072a5a6590c60" \
>         cluster-infrastructure="openais" \
>         expected-quorum-votes="2" \
>         no-quorum-policy="ignore" \
>         start-failure-is-fatal="false" \
>         stonith-enabled="true" \
>         last-lrm-refresh="1346358565"
> rsc_defaults $id="rsc-options" \
>         resource-stickiness="100"
>
>
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