B Oracle Clusterware Resource Reference

Resource Attributes

This section lists and describes attributes used when you register applications as resources in Oracle Clusterware. Use these attributes with the crsctl add resource command, as follows:

$ crsctl add resource resource_name -type resource_type
{[-attr "attribute_name='attribute_value', attribute_name='attribute_value'
, ..."] | [-file file_name]}

List attribute-value pairs in a comma-delimited list after the -attr flag and enclose the value of each attribute in single quotation marks (''). Some resource attributes you cannot configure and are read only.

Alternatively, you can create a text file that contains the attribute-value pairs. For example:

PLACEMENT=favored
HOSTING_MEMBERS=node1 node2 node3
RESTART_ATTEMPTS@CARDINALITYID(1)=0
RESTART_ATTEMPTS@CARDINALITYID(2)=0
FAILURE_THRESHOLD@CARDINALITYID(1)=2
FAILURE_THRESHOLD@CARDINALITYID(2)=4
FAILURE_INTERVAL@CARDINALITYID(1)=300
FAILURE_INTERVAL@CARDINALITYID(2)=500
CHECK_INTERVAL=2
CARDINALITY=2

This section includes the following topics:

• Configurable Resource Attributes

• Read-Only Resource Attributes

Configurable Resource Attributes

This section describes the following resource attributes that you can configure when registering an application as a resource in Oracle Clusterware:

• ACL

• ACTION_SCRIPT

• ACTIVE_PLACEMENT

• AGENT_FILENAME

• AUTO_START

• CARDINALITY

• CHECK_INTERVAL

• DEGREE

• DESCRIPTION

• ENABLED

• FAILURE_INTERVAL

• FAILURE_THRESHOLD

• HOSTING_MEMBERS

• LOAD

• NAME

• OFFLINE_CHECK_INTERVAL

• PLACEMENT

• RESTART_ATTEMPTS

• SCRIPT_TIMEOUT

• SERVER_POOLS

• START_DEPENDENCIES

• START_TIMEOUT

• STOP_DEPENDENCIES

• STOP_TIMEOUT

• TYPE

• UPTIME_THRESHOLD

ACL

Defines the owner of a resource and the access privileges granted to various operating system users and groups. The resource owner defines the operating system user of the owner and its privileges. You configure this optional attribute when you create a resource. If you do not configure this attribute, then the value is based on the identity of the process creating a resource. You can change the value of the attribute if such a change is allowed based on the existing privileges of the resource.

In the string:

• owner: The operating system user that owns a resource and the user under which the action script or application-specific agent run, followed by the privileges of the owner.

• pgrp: The operating system group that is the primary group of the owner of a resource, followed by the privileges of members of the primary group.

• other: Followed by privileges of others.

• r: This access option is the read option and gives the ability to only see a resource, its state, and configuration

• w: This access option gives the ability to modify a resource's attributes and to delete the resource

• x: This access option gives the ability to start, stop, and relocate a resource

By default, the identity of the client that creates a resource is the owner. Also by default, root, and the user specified in owner have full privileges. You can grant required operating system users and operating system groups their privileges by adding the following lines to the ACL attribute:

user:user_name:rwx
group:group_name:rwx

Usage Example

ACL=owner:user_1:rwx,pgrp:osdba:rwx,other::r-

ACTION_SCRIPT

An absolute file name that includes the path and file name of an action script. The agent specified in the AGENT_FILENAME attribute calls the script specified in the ACTION_SCRIPT attribute.

Usage Example

ACTION_SCRIPT=fully_qualified_path_to_action_script

ACTIVE_PLACEMENT

When set to 1, Oracle Clusterware uses this attribute to reevaluate the placement of a resource during addition or restart of a cluster server. For resources where PLACEMENT=favored, Oracle Clusterware may relocate running resources if the resources run on a non-favored server when a favored one joins the cluster.

Usage Example

ACTIVE_PLACEMENT=1

AGENT_FILENAME

A fully qualified file name of an agent program that a resource type uses to manage its resources. Every resource type must have an agent program to manage its resources. Resource types use agent programs by either specifying a value for this attribute or inheriting it from their base resource type. There are two script agents included with Oracle Clusterware 11g release 2 (11.2): application and scriptagent. Oracle Clusterware uses the application script agent for resources of the deprecated application resource type. The default value for this attribute is scriptagent.

Usage Example

AGENT_FILENAME=%Grid_home%/bin/application

AUTO_START

Indicates whether Oracle Clusterware automatically starts a resource after a cluster server restart. Valid AUTO_START values are:

• 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.

CARDINALITY

The number of servers on which a resource can run, simultaneously. This is the upper limit for resource cardinality.

Usage Example

CARDINALITY=1

CHECK_INTERVAL

The time interval, in seconds, between repeated executions of the check action. Shorter intervals enable more frequent checks but also increase resource consumption if you use the script agent. Use an application-specific agent to reduce resource consumption.

Usage Example

CHECK_INTERVAL=60

DEGREE

The number of instances of a cluster resource that can run on a single server.

Usage Example

DEGREE=1

DESCRIPTION

Enter a description of the resource you are adding.

Usage Example

DESCRIPTION=Apache Web server

ENABLED

Oracle Clusterware uses this attribute to manage the state of the resource. Oracle Clusterware does not attempt to manage a disabled (ENABLED=0) resource either directly or because of a dependency to another resource. A disabled resource cannot be started but it can be stopped.

Oracle Clusterware does not actively monitor disabled resources, meaning that Oracle Clusterware does not check their state. However, when Oracle Clusterware starts, it does query the state of disabled resources.

Usage Example

ENABLED=1

FAILURE_INTERVAL

The interval, in seconds, during which Oracle Clusterware applies the FAILURE_THRESHOLD attribute. If the value is zero (0), then tracking of failures is disabled.

Usage Example

FAILURE_INTERVAL=30

FAILURE_THRESHOLD

The number of failures detected within a specified FAILURE_INTERVAL for a resource before Oracle Clusterware marks the resource as unavailable and no longer monitors it. If a resource fails the specified number of times, then Oracle Clusterware stops the resource. If the value is zero (0), then tracking of failures is disabled. The maximum value is 20.

Usage Example

FAILURE_THRESHOLD=3

HOSTING_MEMBERS

A space-separated, ordered list of cluster server names that can host a resource. This attribute is required only when using administrator management, and when the value of the PLACEMENT attribute is set to favored or restricted. When registering applications as Oracle Clusterware resources, use the SERVER_POOLS attribute, instead.

To obtain a list of candidate node names, run the olsnodes command to display a list of your server names.

Usage Example

HOSTING_MEMBERS=server1 server2 server3

LOAD

Oracle Clusterware interprets the value of this attribute along with that of the PLACEMENT attribute. When the value of PLACEMENT is balanced, the value of LOAD determines where best to place a resource. A nonnegative, numeric value that quantitatively represents how much server capacity an instance of a resource consumes relative to other resources. Oracle Clusterware attempts to place resources on servers with the least total load of running resources.

Usage Example

LOAD=1

NAME

A case-sensitive, alphanumeric string that names the resource. Oracle recommends a naming convention is to that starts with an alphanumeric prefix, such as sky1, and complete the name with an identifier to describe it. A resource name can contain any platform-supported characters except the exclamation point (!) and the tilde (~). A resource name cannot begin with a period (.) nor with the string ora.

Usage Example

NAME=myApache

OFFLINE_CHECK_INTERVAL

Controls offline monitoring of a resource. The value represents the interval (in seconds) that Oracle Clusterware monitors a resource when its state is OFFLINE. Monitoring is disabled if the value is 0.

Usage Example

OFFLINE_CHECK_INTERVAL=30

PLACEMENT

Specifies how Oracle Clusterware selects a cluster server on which to start a resource. Valid values are balanced, favored, or restricted.

If you set the PLACEMENT attribute to favored or restricted, then you must also assign values to the SERVER_POOLS and HOSTING_MEMBERS attributes. If you set the value of the PLACEMENT attribute to balanced, then the HOSTING_MEMBERS attribute is not required.

Usage Example

PLACEMENT=favored

RESTART_ATTEMPTS

The number of times that Oracle Clusterware attempts to restart a resource on the resource's current server before attempting to relocate it. A value of 1 indicates that Oracle Clusterware only attempts to restart the resource once on a server. A second failure causes Oracle Clusterware to attempt to relocate the resource. A value of 0 indicates that there is no attempt to restart but Oracle Clusterware always tries to fail the resource over to another server.

Usage Example

RESTART_ATTEMPTS=2

SCRIPT_TIMEOUT

The maximum time (in seconds) for an action to run. Oracle Clusterware returns an error message if the action script does not complete within the time specified. The timeout applies to all actions (start, stop, check, and clean).

Usage Example

SCRIPT_TIMEOUT=45

SERVER_POOLS

This attribute creates an affinity between a resource and one or more server pools regarding placement, and is dependent on the value of the PLACEMENT attribute.

If a resource can run on any server in a cluster, then use the default value, *. Only cluster administrators can specify * as the value for this attribute. Otherwise, you must specify in the SERVER_POOLS attribute a space-separated list of the server pools to which a particular resource can belong.

• Use the PLACEMENT attribute with the SERVER_POOLS attribute, as follows: If you set the value of the PLACEMENT attribute to either restricted or favored, then you must also provide a value for the SERVER_POOLS attribute when using policy management for the resource.

• If the value for PLACEMENT is set to balanced, then no value for the SERVER_POOLS attribute is required.

Usage Example

SERVER_POOLS=pool1 pool2 pool3

START_DEPENDENCIES

Specifies a set of relationships that Oracle Clusterware considers when starting a resource. You can specify a space-separated list of dependencies on several resources and resource types on which a particular resource can depend.

Syntax

START_DEPENDENCIES=dependency(resource_set) [dependency(resource_set)] [...]

In the preceding syntax example the variables are defined, as follows:

• dependency: Possible values are hard, weak, attraction, pullup, and dispersion. You can specify each dependency only once, except for pullup, which you can specify multiple times.

• resource_set: A comma-delimited list of resource entities—either individual resources or resource types—enclosed in parentheses (), in the form of res1[, res2[, ...]], upon which the resource you are configuring depends.

  Each resource entity is defined, as follows:

  [modifier1:[modifier2:]] {resource_name | type:resource_type}
  

  In the preceding syntax example, resource_name is the name of a specific resource and type:resource_type is the name of a specific resource type. The resource type must be preceded by type:.

  Optionally, you can specify modifiers to further configure resource entity dependencies. You can modify each dependency by prefixing the following modifiers to the resource entity:

  • 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.

    Use intermediate to specify that Oracle Clusterware can start this resource if a resource on which it depends is in either the ONLINE or INTERMEDIATE state. If not specified, then resources must be in the ONLINE state for Oracle Clusterware to start this resource.

    Use global to specify that resources are not required to reside on the same server as a condition to Oracle Clusterware starting this resource. If not specified, then resources must reside on the same server for Oracle Clusterware to start this resource.

    If you specify the hard dependency on a resource type for a resource, then the resource can start if any resource of that particular type is running.

    Note:

    Oracle recommends that resources with hard start dependencies also have pullup start dependencies.

  • 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.

    Use concurrent to specify that Oracle Clusterware can start a dependent resource while a resource on which it depends is in the process of starting. If not specified, then resources must complete startup before Oracle Clusterware can start the dependent resource.

    Use global to specify that resources are not required to reside on the same server as a condition to Oracle Clusterware starting the dependent resource.

    Use uniform to start all instances of the resource everywhere the resource can run. If you do not specify a modifier (the default), then the resource starts on the same server as the resource on which it depends.

    If you specify the weak start dependency on a resource type for a resource, then the resource can start if any resource of that particular type is 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.

    Use intermediate to specify that this resource is attracted to resource entities on which it depends that are in the INTERMEDIATE state. If not specified, then resources must be in the ONLINE state to attract the dependent resource.

    If you specify the attraction dependency on a resource type for a resource, then any resource of that particular type attracts the dependent resource.

  • 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.

    Use the always modifier for pullup so that Oracle Clusterware starts this resource despite the value of its TARGET attribute, whether that value is ONLINE or OFFLINE. Otherwise, if you do not specify the always modifier, then Oracle Clusterware starts this resource only if the value of the TARGET attribute is ONLINE for the resources on which it depends.

    Use intermediate to specify that Oracle Clusterware can start this resource if a resource on which it depends is in either the ONLINE or INTERMEDIATE state. If not specified, then resources must be in the ONLINE state for Oracle Clusterware to start this resource.

    Use global to specify that resources on which this resource depends are not required to reside on the same server as a condition to Oracle Clusterware starting this resource. If not specified, then resources on which this resource depends must reside on the same server for Oracle Clusterware to start this resource.

    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.

    Note:

    Oracle recommends that resources with hard start dependencies also have pullup start dependencies.

  • dispersion[:active]([intermediate:]{resource_name | type:resource_type}): Specify the dispersion start dependency for a resource that you want to run on a server that is different from the named resources or resources of a particular type. Resources may still end up running on the same server, depending on availability of servers.

    Use the active modifier to configure the dispersion dependency so that Oracle Clusterware attempts to relocate the dependent resource to another server if it is co-located with another resource and another server comes online. Oracle Clusterware does not relocate resources to newly available servers unless you specify the active modifier.

    Use intermediate to specify that Oracle Clusterware can relocate the dependent resource if a resource is in either the ONLINE or INTERMEDIATE state. If not specified, then resources must be in the ONLINE state for dispersion of the dependent resource to occur.

START_TIMEOUT

The maximum time (in seconds) in which a start action can run. Oracle Clusterware returns an error message if the action does not complete within the time specified. If you do not specify a value for this attribute or you specify 0 seconds, then Oracle Clusterware uses the value of the SCRIPT_TIMEOUT attribute.

Usage Example

START_TIMEOUT=30

STOP_DEPENDENCIES

Specifies a set of relationships that Oracle Clusterware considers when stopping a resource.

Syntax

STOP_DEPENDENCIES=dependency(resource_set) [dependency(resource_set)] ...

In the preceding syntax example the variables are defined, as follows:

• dependency: The only possible value is hard.

• resource_set: A comma-delimited list, in the form of res1[, res2 [,...]], of resource entities—either individual resources or resource types—upon which the resource you are configuring depends.

  Each resource entity is defined, as follows:

  [modifier1:[modifier2:][modifier3:]] resource_name | type:resource_type
  

  In the preceding syntax example, resource_name is the name of a specific resource and type:resource_type is the name of a specific resource type. The resource type must be preceded by type:.

  Optionally, you can specify modifiers to further configure resource entity dependencies. You can modify each dependency by prefixing the following modifiers to the resource entity:

  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.

  Use intermediate to specify that the dependent resource can remain in an ONLINE state if a resource is in either the ONLINE or INTERMEDIATE state. If not specified, then Oracle Clusterware stops the dependent resource unless resources are in the ONLINE state.

  Use global to specify that the dependent resource remains in an ONLINE state if a resource is in an ONLINE state on any node in the cluster. If not specified, then when resources residing on the same server go offline, Oracle Clusterware stops the dependent resource.

  Use shutdown to apply this dependency when the Oracle Clusterware stack is shut down. This is a convenient way to affect the order of stopping resources when stopping the stack, without having any affect on planned or unplanned events on the individual resources. This dependency, when used with the shutdown modifier, does not go into effect if somebody stops the resource directly, but only when the stack is shut down.

STOP_TIMEOUT

The maximum time (in seconds) in which a stop or clean action can run. Oracle Clusterware returns an error message if the action does not complete within the time specified. If you do not specify this attribute or if you specify 0 seconds, then Oracle Clusterware uses the value of the SCRIPT_TIMEOUT attribute.

Usage Example

STOP_TIMEOUT=30

TYPE

The type of resource indicated when you create a resource. This attribute is required when creating a resource.

Usage Example

crsctl add resource resource_name -type resource_type

UPTIME_THRESHOLD

The value for UPTIME_THRESHOLD represents the length of time that a resource must be up before Oracle Clusterware considers the resource to be stable. By setting a value for the UPTIME_THRESHOLD attribute, you can indicate the stability of a resource.

Enter values for this attribute as a number followed by a letter that represents seconds (s), minutes (m), hours (h), days (d), or weeks (w). For example, a value of 7h represents an uptime threshold of seven hours.

After the time period you specify for UPTIME_THRESHOLD elapses, Oracle Clusterware resets the value for CURRENT_RCOUNT to 0. Oracle Clusterware can alert you when the value for CURRENT_RCOUNT reaches the value that you set for RESTART_ATTEMPTS.

Read-Only Resource Attributes

You can view these attributes when you run the crsctl status resource command on a particular resource. Oracle Clusterware sets these attributes when you register resources.

• ACTION_FAILURE_EVENT_TEMPLATE

• LAST_SERVER

• PROFILE_CHANGE_EVENT_TEMPLATE

• CURRENT_RCOUNT

• STATE_CHANGE_EVENT_TEMPLATE

• STATE_DETAILS

• TARGET

ACTION_FAILURE_EVENT_TEMPLATE

This is an internally-managed attribute that you can view only when you run the crsctl status resource command on an ora resource. You cannot edit this attribute.

CURRENT_RCOUNT

The Oracle Clusterware daemon counts the number of attempts to restart a resource, starting from zero up to the value specified in the RESTART_ATTEMPTS attribute.

LAST_SERVER

For cluster_resource-type resources, this is an internally managed, read-only attribute that contains the name of the server on which the last start action for the resource succeeded.

For local_resource-type resources, this is the name of the server to which the resource instance is pinned.

PROFILE_CHANGE_EVENT_TEMPLATE

This is an internally-managed attribute that you can view only when you run the crsctl status resource command on an ora resource. You cannot edit this attribute.

STATE_CHANGE_EVENT_TEMPLATE

This is an internally-managed attribute that you can view only when you run the crsctl status resource command on an ora resource. You cannot edit this attribute.

STATE_DETAILS

An internally managed, read-only attribute that contains details about the state of a resource.

The four resource states—ONLINE, OFFLINE, UNKNOWN, and INTERMEDIATE—may map to different resource-specific values, such as mounted, unmounted, and open. Resource agent developers can use the STATE_DETAILS attribute to provide a more detailed description of this mapping, resource to the resource state.

Providing details is optional. If details are not provided, then Oracle Clusterware uses only the four possible resource states. Additionally, if the agent cannot provide these details (as may also happen to the value of the resource state), then Oracle Clusterware sets the value of this attribute to provide minimal details about why the resource is in its current state.

TARGET

An internal, read-only attribute that describes the desired state of a resource. Using the crsctl start resource_name or crsctl stop resource_name commands, however, can affect the value of this attribute.

Third-Party Applications Using the Script Agent

This section includes examples of third-party applications using script agents.

Example B-1 shows an action script that fails over the Apache Web server.

#!/bin/sh

HTTPDCONFLOCATION=/etc/httpd/conf/httpd.conf
WEBPAGECHECK=http://<MyVIP>:80/icons/apache_pb.gif

case $1 in
'start')
    /usr/sbin/apachectl -k start -f $HTTPDCONFLOCATION
   RET=$?
    ;;
'stop')
    /usr/sbin/apachectl -k stop
   RET=$?
    ;;
'clean')
    /usr/sbin/apachectl -k stop
   RET=$?
    ;;
'check')
    /usr/bin/wget -q --delete-after $WEBPAGECHECK
   RET=$?
    ;;
*)
   RET=0
    ;;
esac
# 0: success; 1 : error
if [ $RET -eq 0 ]; then
exit 0
else
exit 1
fi

Example B-2 shows the xclock script, which is a simple action script using xclock available as a default binary on all Linux and UNIX platforms.

#!/bin/bash
# start/stop/check script for xclock example
# To test this change BIN_DIR to the directory where xclock is based
# and set the DISPLAY variable to a server within your network.

BIN_DIR=/usr/X11R6/bin
LOG_DIR=/tmp
BIN_NAME=xclock
DISPLAY=yourhost.domain.com:0.0
export DISPLAY

if [ ! -d $BIN_DIR ]
then
        echo "start failed"
        exit 2
fi

PID1=`ps -ef | grep $BIN_NAME | grep -v grep | grep -v xclock_app | awk '{ print $2 }'`
case $1 in
'start')
        if [ "$PID1" != "" ]
        then
           status_p1="running"
        else
           if [ -x $BIN_DIR/$BIN_NAME ]
           then
             umask 002
             ${BIN_DIR}/${BIN_NAME} & 2>${LOG_DIR}/${BIN_NAME}.log
             status_p1="started"
           else
             echo `basename $0`": $BIN_NAME: Executable not found"
           fi
        fi

         echo "$BIN_NAME: $status_p1"
        ;;

'stop')
        if [ "${PID1}" != "" ]
        then
           kill -9 ${PID1} && echo "$BIN_NAME daemon killed"
        else
           echo "$BIN_NAME: no running Process!"
        fi
        ;;
'check')
        if [ "$PID1" != "" ]
        then
           echo "running"
           exit 0
        else
           echo "not running"
           exit 1 
        fi
        ;;*)
        echo "Usage: "`basename $0`" {start|stop|check}"
        ;;
esac

Example B-3 shows an example of a shell script for an agent to monitor a file. When the agent is started, it creates the file (which is specified through an attribute) and when it is stopped, it deletes the file. The CHECK action consists of merely checking if the file exists or not. The variables with the _CRS_ prefix are attribute values that are provided to the script in its environment.

#!/bin/sh
TOUCH=/bin/touch
RM=/bin/rm
PATH_NAME=/tmp/$_CRS_NAME

#
# These messages go into the CRSD agent log file.
echo " *******   `date` ********** "
echo "Action script '$_CRS_ACTION_SCRIPT' for resource[$_CRS_NAME] called for action $1"
#

case "$1" in
  'start')
     echo "START entry point has been called.."
     echo "Creating the file: $PATH_NAME"
     $TOUCH $PATH_NAME
     exit 0
     ;;

  'stop')
     echo "STOP entry point has been called.." 
     echo "Deleting the file: $PATH_NAME"
     $RM $PATH_NAME
     exit 0
     ;;

  'check')
    echo "CHECK entry point has been called.."
    if [ -e $PATH_NAME ]; then
        echo "Check -- SUCCESS"
        exit 0
    else
        echo "Check -- FAILED"
        exit 1
    fi
    ;;

  'clean')
     echo "CLEAN entry point has been called.."
     echo "Deleting the file: $PATH_NAME"
     $RM -f $PATH_NAME
     exit 0
     ;;

esac