Reduce Infrastructure costs with Oracle Clusterware

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1 Reduce Infrastructure costs with Oracle Clusterware How to Reduce License Cost without losing High Availability Presented By: Bill Pritchett, Senior Consultant

2 Discussion Topics Advantages of having a single instance database as a clustered resource Process to implement a database as a clustered resource Key Considerations and Attributes when implementing a database as a clustered resource Shared storage options for non oracle files that need to be shared between nodes Documentation Resources Questions 2

3 Advantages of having a single instance database as a clustered resource Reduce Budget Impact Enable automatic Failover of a Database Instance Ability to provide automatic failover for all applications on a database server 3

4 Reduce Budget Impact License one server per cluster for Database use Clusterware and ASM are free with Database License Expenses for Database Licensing are cut in half Reduce future support costs 4

5 Enable automatic Failover of Database Instance Reduce downtime due to unplanned outages Reduce downtime related to Server maintenance Reduce downtime for Database patching Enable automatic failover for NIC Card related issues Enable automatic failover when network issues occur 5

6 Provide automatic failover for all applications on a database server Remove need for manual application migration Reduce downtime related to Server maintenance Enable Cluster management of non Oracle Applications 6

7 Process to implement a database to a clustered resource Install Software and Create Database Create an Action Script Create a resource attribute file Remove Database from cluster Add database back to cluster as a clustered resource 7

8 Install Software and Create Database Install Clusterware on all servers Request 3 Ips per server and 3 Ips for the SCAN Listener Verify all Ips except the private Ips resolve using nslookup (This includes reverse lookup) Create Voting Disk ASM diskgroup Verify passwordless SSH capability for Clusterware Owner Create rest of ASM Diskgroups 8

9 Install Software and Create Database (Continued) Install the Database software using the RAC install option Select install Database Software only Select Oracle Real Application Clusters database installation Select all cluster nodes Verify passwordless SSH capability for Database software Owner Create Single instance database using DBCA Make Sure to Select Oracle Single Instance Database 9

10 Create an Action Script Action Scripts are required for managing an application as a clustered resource. Action Scripts must be owned by Oracle and executable by Root Should be created in a directory owned by Oracle under the GRID_HOME/crs directory The Action Script is usually a perl or shell script. It consists of the following: Oracle Home and Oracle Sid variables Case statement containing the following entry points: Start, Stop, Clean, Check and abort(optional) IF statement test case to determine success or failure of entry point 10

11 Create an Action Script Start Entry Point The START entry point acts to bring a resource online. The agent framework calls this entry point whenever it receives the start command from Oracle Clusterware. Example Start entry Point 'start') $ORACLE_HOME/bin/sqlplus /nolog <<EOF conn / as sysdba startup exit EOF RET=0 ;; 11

12 Create an Action Script Stop Entry Point The STOP entry points acts to gracefully bring down a resource. The agent framework calls this entry point whenever it receives the stop command from Oracle Clusterware. Example Stop entry Point 'stop') $ORACLE_HOME/bin/sqlplus /nolog <<EOF conn / as sysdba shutdown immediate exit EOF RET=0 ;; 12

13 Create an Action Script Clean Entry Point The CLEAN entry point acts whenever there is a need to clean up a resource. It is a non-graceful operation that is invoked when users must forcefully terminate a resource. This command cleans up the resourcespecific environment so that the resource can be restarted. Example Clean entry Point 'clean') $ORACLE_HOME/bin/sqlplus /nolog <<EOF conn / as sysdba shutdown abort exit EOF RET=0 ;; 13

14 Create an Action Script Check Entry Point The CHECK (monitor) entry point acts to monitor the health of a resource. The agent framework periodically calls this entry point. If it notices any state change during this action, then the agent framework notifies Oracle Clusterware about the change in the state of the specific resource Example Check entry Point 'check') ok=`ps -ef grep smon grep $ORACLE_SID grep -v grep wc -l` if [ $ok = 0 ]; then RET=1 else RET=0 fi ;; 14

15 Create an Action Script Abort Entry Point If any of the other entry points hang, the agent framework calls the ABORT entry point to abort the ongoing action. If the agent developer does not supply an abort function, then the agent framework exits the agent program.example Check entry Point Optional Entry Point abort') killcmd=`ps -ef grep pmon grep $ORACLE_SID grep -v grep awk {print $2} ` kill -9 $killcmd if [ $? = 0 ]; then RET=0 else RET=1 fi ;; 15

16 Create a resource attribute file The Attributes of a database differ from the Attributes of a clustered resource. This creates the need to modify the resource attributes Create a resource file by running the following command $GRID_HOME/bin/crsctl stat res <db resource name> -p > mydb_resource.txt Modify resource attributes to resemble a clustered resource TYPE ACTION_SCRIPT AUTO_START START_DEPENDENCIES STOP_DEPENDENCIES 16

17 Remove Database from cluster (As Database Owner) Shutdown the database srvctl stop database d <database name> Remove the database from the cluster srvctl remove database d <database name> 17

Add database back to cluster as a clustered resource (As Database Owner) To Add the Database as a clustered Resource use the following command $GRID_HOME/bin/crsctl add

18 Add database back to cluster as a clustered resource (As Database Owner) To Add the Database as a clustered Resource use the following command $GRID_HOME/bin/crsctl add resource <database name>.db type cluster_resource file <full path to resource file> Then start the resource $GRID_HOME/bin/crsctl start resource ora.mytest.db -n <hostname> 18

19 Key Considerations and attributes when implementing a database as a Clustered Resource Considerations Command restrictions License restrictions TNS Information Diagnostic and Admin directories Attributes AUTO_START START_DEPENDENCIES STOP_DEPENDENCIES How to modify attributes 19

20 Key Considerations Command line startup options are limited Inability to start the database in restrict mode or mount state using srvctl commands Database may only run on secondary node 10 days out of a calendar year A day is considered used whether it runs on secondary node10 minutes or 23 hours Talk to your License representative for more information Copy the TNSNAMES.ora file from Node 1 to Node 2 Modify the local listener TNS entry on Node 2 to point to Node 2 Build Diagnostics and Admin directory structures on Node 2 Diagnostics directory should be on shared storage if possible 20

21 Key Attribute AUTO_START Determines how the resource is started after a system reboot. The following settings are valid always: Restarts the resource when the server restarts regardless of the state of the resource when the server stopped. restore: Restores the resource to the same state that it was in when the server stopped. Oracle Clusterware attempts to restart the resource if the value of TARGET was ONLINE before the server stopped. never: Oracle Clusterware never restarts the resource regardless of the state of the resource when the server stopped. An AUTO_START setting of never can be overridden if the START_DEPENDENCIES attribute contains any pullup dependencies. If you only license one server of the cluster then you should set AUTO_START to never so that you can make sure the database starts up on node one 21

22 Key Attribute START_DEPENDENCIES Enforces resource dependencies so that the resource only starts once all the dependencies are met. The following types of dependencies are valid hard([intermediate:][global:]{resource_name type:resource_type}):specify a hard start dependency for a resource when you want the resource to start only when a particular resource or resource of a particular type starts. weak([concurrent:][global:][uniform:]{resource_name type:resource_type}): Specify a weak start dependency for a resource when you want that resource to start despite whether named resources are running, or not. An attempt to start this resource also attempts to start any resources on which this resource depends if they are not running. attraction([intermediate:]{resource_name type:resource_type}):use the attraction start dependency when you want this resource to run on the same server with a particular named resource or any resource of a particular type. pullup[:always]([intermediate:][global:]{resource_name type:resource_type}):when you specify the pullup start dependency for a resource, then this resource starts as a result of named resources starting. 22

23 Key Attribute START_DEPENDENCIES (Continued) Oracle recommends that resources with hard start dependencies also have pullup start dependencies. If you specify the pullup dependency on a resource type for a resource, then, when any resource of that particular type starts, Oracle Clusterware can start this resource. This causes the AUTO_START setting of NEVER to be overridden From my example file START_DEPENDENCIES=hard(ora.DATA.dg,ora.ARCH.dg) weak(type:ora.listener.type,uniform:ora.ons) 23

24 Key Attribute STOP_DEPENDENCIES Enforce resource dependencies for shutting down the resource. The only type of dependency available is hard hard([intermediate:][global:][shutdown:]{resource_name type:resource_type}): Specify a hard stop dependency for a resource that you want to stop when named resources or resources of a particular resource type stop. If you want the database to failover to the passive node when there are issues with the Public Network then you have to specify the network as a dependency From my example file STOP_DEPENDENCIES=hard(intermediate:ora.asm,shutdown:ora.DAT A.dg,shutdown:ora.ARCH.dg,ora.net1.network) 24

25 How to modify attributes To modify the attributes of a resource you use the following command $GRID_HOME/bin/crsctl modify res <resource name> -attr <Attribute Name>= value Multiple attributes may be listed in the double quotes by using commas between the Attributes 25

26 Shared storage options for non oracle files that need to be shared between nodes To help manage files needed on both servers the Storage options listed below are available. Examples of files needed on both servers are Backup scripts Database Diag information Monitoring scripts ACFS (ASM Clustered Filesystem) utilizes ASM to manage the mountpoints NFS (Network File System) If NFS is chosen please verify the resource stop_dependencies setting includes the public network. Otherwise the database will hang if your server loses the Public Network 26

27 Documentation Resources Cluster Admin Guide 11gR2 Clusterware Administration and Deployment Guide SOP Single Single Instance Database on Grid Infrastructure 27

28 Questions 28

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