HA - order lost when group made

SLES High Availability Extension
1

HA - order lost when group made

SLES 15 SP1 + HA

2 node HA cluster setup for DRBD storage

Made an order constraint for resource virtual IPs, iSCSI targets and iSCSI LUs.

These resources need to be started in order
Te resources can be start individually (and stopped individually) (before order constraint is made)

order o_drbd02_before_iscsitgt02 Serialize: p-ip-14-202:start p-ip-15-202:start p_target_drbd02:start p-lu-drbd02:start
or
order o_drbd02_before_iscsitgt02 Serialize: ( p-ip-14-202:start p-ip-15-202:start ) ( p_target_drbd02:start ) ( p-lu-drbd02:start )

Now to make a group resource with the same resources, but when the group is made, the order constraint is gone

group g-drbd02 p-ip-14-202 p-ip-15-202 p-lu-drbd02 p_target_drbd02 meta target-role=Stopped

Adding the group with ‘crm configure edit’ returns these comments

nss-sn02:~ # crm configure edit
INFO: modified colocation:cl-drbd02 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd03_before_iscsitgt from p-ip-14-202 to g-drbd02
INFO: modified colocation:cl-drbd03 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-ip-15-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-lu-drbd02 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p_target_drbd02 to g-drbd02

How can a order be made of the same group resources?

2

[QUOTE=johngoutbeck;58874]HA - order lost when group made

SLES 15 SP1 + HA

2 node HA cluster setup for DRBD storage

Made an order constraint for resource virtual IPs, iSCSI targets and iSCSI LUs.

These resources need to be started in order
Te resources can be start individually (and stopped individually) (before order constraint is made)

order o_drbd02_before_iscsitgt02 Serialize: p-ip-14-202:start p-ip-15-202:start p_target_drbd02:start p-lu-drbd02:start
or
order o_drbd02_before_iscsitgt02 Serialize: ( p-ip-14-202:start p-ip-15-202:start ) ( p_target_drbd02:start ) ( p-lu-drbd02:start )

Now to make a group resource with the same resources, but when the group is made, the order constraint is gone

group g-drbd02 p-ip-14-202 p-ip-15-202 p-lu-drbd02 p_target_drbd02 meta target-role=Stopped

Adding the group with ‘crm configure edit’ returns these comments

nss-sn02:~ # crm configure edit
INFO: modified colocation:cl-drbd02 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd03_before_iscsitgt from p-ip-14-202 to g-drbd02
INFO: modified colocation:cl-drbd03 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-ip-14-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-ip-15-202 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p-lu-drbd02 to g-drbd02
INFO: modified order:o_drbd02_before_iscsitgt02 from p_target_drbd02 to g-drbd02

How can a order be made of the same group resources?[/QUOTE]

Found this info on cluster resource groups
https://www.golinuxcloud.com/understanding-resource-group-constraints-cluster-examples/

Understanding Resource Groups

Resources in a group are always kept together on the same node, and they will also be started in the order in which they are listed in the group.

Group benefits

Combines resource primitives in a single entity that can be managed which means that instead of starting a resource individually you can start the group and it will start all the resources in that group
Provides specific ordering
Provides specific dependencies
If using constraints, they should point at the entire group and not it’s members
Stickiness score is the sum of all member stickiness scores

–

changed my cluster configuration to

–
group g-drbd02 p-ip-14-202 p-ip-15-202 p-target-drbd02 p-lu-drbd02 \
meta target-role=Started

ms ms-drbd02 drbd02 \
meta master-max=1 master-node-max=1 clone-max=2 clone-node-max=1 notify=true target-role=Stopped

Hope this helps others

3

Receive a rely from another post on ClusterLabs from Ulrich in Germany

  • ‘groups always had implicit colocation and ordering.’