CLUSTERWARE PROCESSES in 11g RAC R2 Environment

CLUSTERWARE PROCESSES in 11g RAC R2 Environment
By user782636 on Dec 14, 2011

i).Cluster Ready Services (CRS)


$ ps -ef | grep crs | grep -v grep


root 25863 1 1 Oct27 ? 11:37:32 /opt/oracle/grid/product/11.2.0/bin/crsd.bin reboot


crsd.bin => The above process is responsible for start, stop, monitor and failover of resource. It maintains OCR and also restarts the resources when the failure occurs.


This is applicable for RAC systems. For Oracle Restart and ASM ohasd is used.


ii).Cluster Synchronization Service (CSS)


$ ps -ef | grep -v grep | grep css


root 19541 1 0 Oct27 ? 00:05:55 /opt/oracle/grid/product/11.2.0/bin/cssdmonitor

root 19558 1 0 Oct27 ? 00:05:45 /opt/oracle/grid/product/11.2.0/bin/cssdagent

oragrid 19576 1 6 Oct27 ? 2-19:13:56 /opt/oracle/grid/product/11.2.0/bin/ocssd.bin


cssdmonitor => Monitors node hangs(via oprocd functionality) and monitors OCCSD process hangs (via oclsomon functionality) and monitors vendor clusterware(via vmon functionality).This is the multi threaded process that runs with elavated priority.


Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdmonitor



cssdagent => Spawned by OHASD process.Previously(10g) oprocd, responsible for I/O fencing.Killing this process would cause node reboot.Stops,start
checks the status of occsd.bin daemon


Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdagent


occsd.bin => Manages cluster node membership runs as oragrid user.Failure of this process results in node restart.


Startup sequence: INIT --> init.ohasd --> ohasd --> ohasd.bin --> cssdagent --> ocssd --> ocssd.bin



iii) Event Management (EVM)


$ ps -ef | grep evm | grep -v grep


oragrid 24623 1 0 Oct27 ? 00:30:25 /opt/oracle/grid/product/11.2.0/bin/evmd.bin

oragrid 25934 24623 0 Oct27 ? 00:00:00 /opt/oracle/grid/product/11.2.0/bin/evmlogger.bin -o /opt/oracle/grid/product/11.2.0/evm/log/evmlogger.info -l /opt/oracle/grid/product/11.2.0/evm/log/evmlogger.log


evmd.bin => Distributes and communicates some cluster events to all of the cluster members so that they are aware of the cluster changes.


evmlogger.bin => Started by EVMD.bin reads the configuration files and determines what events to subscribe to from EVMD and it runs user defined actions for those events.



iv).Oracle Root Agent


$ ps -ef | grep -v grep | grep orarootagent


root 19395 1 0 Oct17 ? 12:06:57 /opt/oracle/grid/product/11.2.0/bin/orarootagent.bin

root 25853 1 1 Oct17 ? 16:30:45 /opt/oracle/grid/product/11.2.0/bin/orarootagent.bin


orarootagent.bin => A specialized oraagent process that helps crsd manages resources owned by root, such as the network, and the Grid virtual IP address.


The above 2 process are actually threads which looks like processes. This is a Linux specific


v).Cluster Time Synchronization Service (CTSS)


$ ps -ef | grep ctss | grep -v grep


root 24600 1 0 Oct27 ? 00:38:10 /opt/oracle/grid/product/11.2.0/bin/octssd.bin reboot


octssd.bin => Provides Time Management in a cluster for Oracle Clusterware



vi).Oracle Agent


$ ps -ef | grep -v grep | grep oraagent


oragrid 5337 1 0 Nov14 ? 00:35:47 /opt/oracle/grid/product/11.2.0/bin/oraagent.bin

oracle 8886 1 1 10:25 ? 00:00:05 /opt/oracle/grid/product/11.2.0/bin/oraagent.bin

oragrid 19481 1 0 Oct27 ? 01:45:19 /opt/oracle/grid/product/11.2.0/bin/oraagent.bin


oraagent.bin => Extends clusterware to support Oracle-specific requirements and complex resources.
This process runs server callout scripts when FAN events occur. This process was known as RACG in Oracle Clusterware 11g Release 1 (11.1).



ORACLE HIGH AVAILABILITY SERVICES STACK


i) Cluster Logger Service



$ ps -ef | grep -v grep | grep ologgerd


root 24856 1 0 Oct27 ? 01:43:48 /opt/oracle/grid/product/11.2.0/bin/ologgerd -m mg5hfmr02a -r -d /opt/oracle/grid/product/11.2.0/crf/db/mg5hfmr01a


ologgerd => Receives information from all the nodes in the cluster and persists in a CHM repository-based database. This service runs on only two nodes in a cluster













ii).System Monitor Service (osysmond)


$ ps -ef | grep -v grep | grep osysmond


root 19528 1 0 Oct27 ? 09:42:16 /opt/oracle/grid/product/11.2.0/bin/osysmond


osysmond => The monitoring and operating system metric collection service that sends the data to the cluster logger service. This service runs on every node in a cluster



iii). Grid Plug and Play (GPNPD):



$ ps -ef | grep gpn


oragrid 19502 1 0 Oct27 ? 00:21:13 /opt/oracle/grid/product/11.2.0/bin/gpnpd.bin


gpnpd.bin => Provides access to the Grid Plug and Play profile, and coordinates updates to the profile among the nodes of the cluster to ensure that all of the nodes have the most recent profile.


iv).Grid Interprocess Communication (GIPC):


$ ps -ef | grep -v grep | grep gipc


oragrid 19516 1 0 Oct27 ? 01:51:41 /opt/oracle/grid/product/11.2.0/bin/gipcd.bin


gipcd.bin => A support daemon that enables Redundant Interconnect Usage.


v). Multicast Domain Name Service (mDNS):



$ ps -ef | grep -v grep | grep dns


oragrid 19493 1 0 Oct27 ? 00:01:18 /opt/oracle/grid/product/11.2.0/bin/mdnsd.bin


mdnsd.bin => Used by Grid Plug and Play to locate profiles in the cluster, as well as by GNS to perform name resolution. The mDNS process is a background process on Linux and UNIX and on Windows.




vi).Oracle Grid Naming Service (GNS)



$ ps -ef | grep -v grep | grep gns



gnsd.bin => Handles requests sent by external DNS servers, performing name resolution for names defined by the cluster.