Actions due to dependency

Online/Offline of the group is performed from bottom to top according to the dependency in case of online, and from top to bottom in case of offline.
Following are a few examples how MCCS manages the resources after dependency link among the resources when a resource is failed. Attributes and state of resources are defined as the figure below.

[Figure] Resource State Information Charts

Critical Attributes

• Failure occurs from a resource on which critical resource depend.
  
  

[Figure] Example of Failure Occur 1

1. As a failure is occurred at resource a2r2, resource a1 r1 will be taken offline. (Since resource a1 r1 depends on resource a2 r2 which is failed, resource a1 r1 may cannot be online properly.)
2. Since resource a1 r1 has critical attribute, resource a3 r3 and a4 r4 will be taken offline in order to failover the group.
3. As a result, resource a2 r2 is considered as failure and all resources in the group will be taken offline

• Non-critical Resources

[Figure] Example of Failure Occur 2

1. Resource a1 r1 which is not critical is online status.
2. When resource a2 r2 get failed, resource a1 r1 will be taken offline because it dependent on resource a2r2.
3. As a1 resource is not critical, group failover will be not performed. Therefore, the group will be partial online status.

RestartLimit Attribute

RestartLimit is an attribute of the resource type. This value determines how many times the recovery will be attempted until it is finally confirmed that it is failure. 

(Please refer to "6. Resource Type" for more details.)

[Figure] Example of Failure Occur 3

1. On the assumption that the value of RestartLimit is 1 for resource a2r2, the first failure has occurred.
2. MCCS will bring online resource a2 r2 again as the value of RestartLimit. At  
   At this time, resource a1 r1 which depends on resource a2 r2 will not be taken offline because resource a2 will be bring online immediately on the local node. .
3. resource r2 restart.
4. resource r1 online.
5. When another failure occurs on resource a2 and if resource a1 has critical attributer2, all of the resource will be taken offline from resource a1 r1 to a3 r3 by order.
6. Resource a3 r3 will be taken offline.
7. As a result, resource a2 r2 is considered as failure and all resources in the group is offline status in the node.