Oracle 10g Clusterware (CRS) Overview 18 Aug 2005 John Sheaffer Platform Solution Specialist [email protected] Topics What is the Oracle Clusterware Clusterware components – – – Daemons VIP OCR & Voting Files Managing.
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Oracle 10g Clusterware (CRS) Overview
18 Aug 2005 John Sheaffer Platform Solution Specialist [email protected]
Topics
What is the Oracle Clusterware Clusterware components – – – Daemons VIP OCR & Voting Files Managing the Oracle Clusterware Q&A
Key Software Components
Server 1 Listener Oracle RAC ClusterWare OS Server 2 Listener Oracle RAC ClusterWare OS Server 3 Listener Oracle RAC ClusterWare OS
• • •
Server N Listener Oracle RAC ClusterWare OS Raw / CFS / NAS / ASM
What is the Oracle Clusterware?
Oracle’s cluster manager layer for 10g + – – – – – Provides Cluster Management Services Provides High Availability Services Incorporates clustering technology licensed from True64 True Clusters No additional cost – supplied with 10g Database Same implementation on all platforms – Eliminates the need for 3 rd integration, and support party clusterware cost,
Clusterware Components
crsd – Cluster Resource Services Daemon cssd – Cluster Synchronization Services Daemon evmd – Event Manager Daemon oprocd / hangcheck_timer – Node hang detector VIP – Virtual IP OCR – Oracle Cluster Repository Voting Disk – Establishes quorum
Clusterware Components
GSD – Global Services Daemon ONS – Oracle Notification Services Daemon
crsd – CRS Daemon
Monitors the resources cluster that are part of the – Resource can be: Listener VIP ASM Instance Database Instance AWM Service Starts/Stops/Checks/Fails-over resources Maintains config information in the OCR
cssd – CSS Daemon
Provides Group Services to the cluster – Tracks who is part of the cluster – Notifies CRS, RAC, and other cssds when nodes join/leave cluster Provides CRS locking services – – Locking w/in clusterware to coordinate actions across the cluster Entirely separate from Cache Fusion locking Basically, CSS is the “Node Monitor”
evmd – Event Manager Daemon
Provides an event-based messaging channel between crsd, cssd, and other processes Can be extended with custom event handler scripts which evmd executes upon receipt of an event – Example: Node down send e-mail alert Node down log a trouble ticket
VIP – Virtual IP
Each server has: – – Static IP VIP racnode1 (145.1.1.
101 ) racnode1-vip (145.1.1.
201 ) Clients always use the VIP VIP allows rapid detection of server failures
VIP Failover
mydb = x.x.x.201
x.x.x.202
(Static) x.x.x.101
(VIP) x.x.x.201
(VIP) x.x.x.202
(Static) x.x.x.102
VIP Failover
mydb = x.x.x.201
x.x.x.202
(Static) x.x.x.101
TCP Reset (VIP) x.x.x.202
(VIP) x.x.x.201
(Static) x.x.x.102
VIP Failover
mydb = x.x.x.201
x.x.x.202
(Static) x.x.x.101
(VIP) x.x.x.202
(VIP) x.x.x.201
(Static) x.x.x.102
OCR & Voting Disks
Oracle Cluster Repository (OCR) – Binary file containing a database (state directory) of CRS configuration & status information – – Maintained by the CRS Daemon Can be mirrored on 10g R2 Voting Disk – – Used by CSS to resolve split-brain scenarios Can be 1 or 3 files in 10g R2 These files must be outside of ASM Can be either raw partitions or regular files
Querying CRS status
[oracle]$ $CRS_HOME/bin/crs_stat NAME=ora.
linux1.vip
TYPE=application TARGET=ONLINE STATE= ONLINE on linux1 NAME=ora.
linux1.ASM1
.asm
TYPE=application TARGET=ONLINE STATE= ONLINE on linux1 NAME=ora.
linux2.vip
TYPE=application TARGET=ONLINE STATE= ONLINE on linux1 NAME=ora.
linux2.ASM2
.asm
TYPE=application TARGET=ONLINE STATE= OFFLINE on linux2 NAME=ora.ract.
mydb1.inst
TYPE=application TARGET=ONLINE STATE= ONLINE on linux1 NAME=ora.ract.
mydb2.inst
TYPE=application TARGET=ONLINE STATE= OFFLINE on linux2
...
Starting / Stopping CRS
/etc/init.d/init.crs start /etc/init.d/init.crs stop
/etc/init.d/init.crs disable /etc/init.d/init.crs enable
Starting / Stopping Resources
[oracle]$ srvctl stop database –d mydb
– Stops all RAC instances
[root]# srvctl stop nodeapps –n racnode1
– Stops Listener, VIP, GSD, ONS
[oracle]$ srvctl start asm –n racnode1
– Starts ASM on racnode1 and all required dependencies
[oracle]$ srvctl start instance –d mydb –i mydb1
– Starts one instance and all required dependencies