OCSSD (aka CSS daemon) - This process is spawned by the cssdagent process. It runs in both
vendor clusterware and non-vendor clusterware environments. OCSSD's primary job is internode health monitoring and RDBMS instance endpoint discovery. The health monitoring includes a network heartbeat and a disk heartbeat (to the voting files). OCSSD can also evict a node after escalation of a member kill from a client (such as a database LMON process). This is a multi-threaded process that runs at an elevated priority and runs as the Oracle user.
Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdagent --> ocssd --> ocssd.bin
CSSDAGENT - This process is spawned by OHASD and is responsible for spawning the OCSSD process, monitoring for node hangs (via oprocd functionality), and monitoring to the OCSSD process for hangs (via oclsomon functionality), and monitoring vendor clusterware (via vmon functionality). This is a multi-threaded process that runs at an elevated priority and runs as the root user.
Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdagent
CSSDMONITOR - This proccess also monitors for node hangs (via oprocd functionality), monitors the OCSSD process for hangs (via oclsomon functionality), and monitors vendor clusterware (via vmon functionality). This is a multi-threaded process that runs at an elevated priority and runs as the root user.
Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdmonitor
2.0 - DETERMINING WHICH PROCESS IS RESPONSIBLE FOR A REBOOT
Important files to review:
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Clusterware alert log in <GRID_HOME>/log/<nodename>
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The cssdagent log(s) in <GRID_HOME>/log/<nodename>/agent/ohasd/oracssdagent_root
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The cssdmonitor log(s) in <GRID_HOME>/log/<nodename>/agent/ohasd/oracssdmonitor_root
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The ocssd log(s) in <GRID_HOME>/log/<nodename>/cssd
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The lastgasp log(s) in /etc/oracle/lastgasp or /var/opt/oracle/lastgasp
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IPD/OS or OS Watcher data
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'opatch lsinventory -detail' output for the GRID home
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*Messages files: