oracle 10g clusterware (crs) overview 18 aug 2005 john sheaffer platform solution specialist...
TRANSCRIPT
Oracle 10gClusterware (CRS)
Overview
18 Aug 2005
John Sheaffer
Platform Solution Specialist
Topics
What is the Oracle Clusterware Clusterware components
– Daemons– VIP– OCR & Voting Files
Managing the Oracle Clusterware Q&A
Server 1Server 1 Server 2Server 2 Server NServer N
• • •
ClusterWareClusterWare ClusterWareClusterWare ClusterWareClusterWare
Key Software Components
Server 3Server 3
ClusterWareClusterWare
OSOS OSOS OSOSOSOS
Raw / CFS / NAS / ASM
Oracle RACOracle RAC
Listener
Oracle RACOracle RAC
Listener
Oracle RACOracle RAC
Listener
Oracle RACOracle RAC
Listener
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 3rd party clusterware cost, integration, and support
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 that are part of the cluster
– 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 racnode1 (145.1.1.101)– VIP racnode1-vip (145.1.1.201)
Clients always use the VIP
VIP allows rapid detection of server failures
VIP Failover
(Static)x.x.x.101
(Static)x.x.x.102
(VIP)x.x.x.201
(VIP)x.x.x.202
mydb = x.x.x.201x.x.x.202
VIP Failover
(Static)x.x.x.101
(Static)x.x.x.102
(VIP)x.x.x.201
(VIP)x.x.x.202
TCP Reset
mydb = x.x.x.201x.x.x.202
VIP Failover
(Static)x.x.x.101
(Static)x.x.x.102
(VIP)x.x.x.201
(VIP)x.x.x.202
mydb = x.x.x.201x.x.x.202
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]$ $CRS_HOME/bin/crs_stat
NAME=ora.linux1.vipTYPE=applicationTARGET=ONLINESTATE=ONLINE on linux1
NAME=ora.linux1.ASM1.asmTYPE=applicationTARGET=ONLINESTATE=ONLINE on linux1
NAME=ora.linux2.vipTYPE=applicationTARGET=ONLINESTATE=ONLINE on linux1
NAME=ora.linux2.ASM2.asmTYPE=applicationTARGET=ONLINESTATE=OFFLINE on linux2
NAME=ora.ract.mydb1.instTYPE=applicationTARGET=ONLINESTATE=ONLINE on linux1
NAME=ora.ract.mydb2.instTYPE=applicationTARGET=ONLINESTATE=OFFLINE on linux2
...
Starting / Stopping CRS
/etc/init.d/init.crs start /etc/init.d/init.crs stop
/etc/init.d/init.crs disable /etc/init.d/init.crs enable
Starting / Stopping Resources
[oracle]$ 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
AQ&Q U E S T I O N SQ U E S T I O N S
A N S W E R SA N S W E R S
