Storage Foundation for Oracle® RAC 7.4.1 Administrator's Guide - Linux
- Section I. SF Oracle RAC concepts and administration
- Overview of Storage Foundation for Oracle RAC
- About Storage Foundation for Oracle RAC
- Component products and processes of SF Oracle RAC
- About Virtual Business Services
- Administering SF Oracle RAC and its components
- Administering SF Oracle RAC
- Starting or stopping SF Oracle RAC on each node
- Administering VCS
- Administering I/O fencing
- About the vxfentsthdw utility
- Testing the coordinator disk group using the -c option of vxfentsthdw
- About the vxfenadm utility
- About the vxfenclearpre utility
- About the vxfenswap utility
- Administering the CP server
- Administering CFS
- Administering CVM
- Changing the CVM master manually
- Administering Flexible Storage Sharing
- Backing up and restoring disk group configuration data
- Administering SF Oracle RAC global clusters
- Administering SF Oracle RAC
- Overview of Storage Foundation for Oracle RAC
- Section II. Performance and troubleshooting
- Troubleshooting SF Oracle RAC
- About troubleshooting SF Oracle RAC
- Troubleshooting I/O fencing
- Fencing startup reports preexisting split-brain
- Troubleshooting CP server
- Troubleshooting server-based fencing on the SF Oracle RAC cluster nodes
- Issues during online migration of coordination points
- Troubleshooting Cluster Volume Manager in SF Oracle RAC clusters
- Troubleshooting CFS
- Troubleshooting interconnects
- Troubleshooting Oracle
- Troubleshooting ODM in SF Oracle RAC clusters
- Prevention and recovery strategies
- Tunable parameters
- Troubleshooting SF Oracle RAC
- Section III. Reference
How intelligent resource monitoring works
When an IMF-aware agent starts up, the agent initializes with the IMF notification module. After the resource moves to a steady state, the agent registers the details that are required to monitor the resource with the IMF notification module. For example, the process agent registers the PIDs of the processes with the IMF notification module. The agent's imf_getnotification function waits for any resource state changes. When the IMF notification module notifies the imf_getnotification function about a resource state change, the agent framework runs the monitor agent function to ascertain the state of that resource. The agent notifies the state change to VCS which takes appropriate action.
A resource moves into a steady state when any two consecutive monitor agent functions report the state as ONLINE or as OFFLINE. The following are a few examples of how steady state is reached.
When a resource is brought online, a monitor agent function is scheduled after the online agent function is complete. Assume that this monitor agent function reports the state as ONLINE. The next monitor agent function runs after a time interval specified by the MonitorInterval attribute. If this monitor agent function too reports the state as ONLINE, a steady state is achieved because two consecutive monitor agent functions reported the resource state as ONLINE. After the second monitor agent function reports the state as ONLINE, the registration command for IMF is scheduled. The resource is registered with the IMF notification module and the resource comes under IMF control.The default value of MonitorInterval is 60 seconds.
A similar sequence of events applies for taking a resource offline.
Assume that IMF is disabled for an agent type and you enable IMF for the agent type when the resource is ONLINE. The next monitor agent function occurs after a time interval specified by MonitorInterval. If this monitor agent function again reports the state as ONLINE, a steady state is achieved because two consecutive monitor agent functions reported the resource state as ONLINE.
A similar sequence of events applies if the resource is OFFLINE initially and the next monitor agent function also reports the state as OFFLINE after you enable IMF for the agent type.