- LMon (lock Monitor) is one of the mandatory background process in Oracle RAC instance.
- It is also called as Global Enqueue Service Monitor
- It manages the Global enqueues and resources.
- LMON manages the instance and process failures. Which includes the releasing the resources, locks during the abnormal termination of the instance or process.
- Cluster Group Services are also managed by LMON.
- LMON taking care the registration of database instance with the node monitoring part of the cluster(CSSD).
- LMON detects the instance transitions and performs reconfiguration of GES and GCS resources.