Declaring Resource Properties

As with resource type properties, you declare resource properties in the RTR file. By convention, resource property declarations follow the resource type declarations in the RTR file. The syntax for resource declarations is a set of attribute value pairs enclosed by braces ({}):

{
    attribute = value;
    attribute = value;
             .
             .
             .
    attribute = value;
}

For resource properties that are provided by Sun Cluster, which are called system-defined properties, you can change specific attributes in the RTR file. For example, Sun Cluster provides default values for method timeout properties for each callback method. In the RTR file, you can specify different default values.

If an RGM method callback times out, the method's process tree is killed by a SIGABRT signal (not a SIGTERM signal). As a result, all members of the process group generate a core dump file in the /var/cluster/core directory. This core dump file is generated to enable you to determine why your method exceeded its timeout.

Avoid writing data service methods that create a new process group. If your data service method must create a new process group, write a signal handler for the SIGTERM and SIGABRT signals. Also, ensure that your signal handler forwards the SIGTERM or SIGABRT signal to the child process group or groups before the signal handler terminates the process. Writing a signal handler for these signals increases the likelihood that all processes that are spawned by your method are correctly terminated.

You can also define new resource properties in the RTR file, which are called extension properties, by using a set of property attributes that are provided by Sun Cluster. Resource Property Attributes lists the attributes for changing and defining resource properties. Extension property declarations follow the system-defined property declarations in the RTR file.

The first set of system-defined resource properties specifies timeout values for the callback methods.

...

# Resource property declarations appear as a list of bracketed
# entries after the resource type declarations. The property 
# name declaration must be the first attribute after the open
# curly bracket of a resource property entry.
#
# Set minimum and default for method timeouts.
{
        PROPERTY = Start_timeout;
        MIN=60;
        DEFAULT=300;
}

{
        PROPERTY = Stop_timeout;
        MIN=60;
        DEFAULT=300;
}
{
        PROPERTY = Validate_timeout;
        MIN=60;
        DEFAULT=300;
}
{
        PROPERTY = Update_timeout;
        MIN=60;
        DEFAULT=300;
}
{
        PROPERTY = Monitor_Start_timeout;
        MIN=60;
        DEFAULT=300;
}
{
        PROPERTY = Monitor_Stop_timeout;
        MIN=60;
        DEFAULT=300;
{
        PROPERTY = Monitor_Check_timeout;
        MIN=60;
        DEFAULT=300;
}

The name of the property (PROPERTY = value) must be the first attribute for each resource-property declaration. You can configure resource properties within limits that are defined by the property attributes in the RTR file. For example, the default value for each method timeout in the sample is 300 seconds. The cluster administrator can change this value. However, the minimum allowable value, specified by the MIN attribute, is 60 seconds. Resource Property Attributes contains a list of resource property attributes.

The next set of resource properties defines properties that have specific uses in the data service.

{
        PROPERTY = Failover_mode;
        DEFAULT=SOFT;
        TUNABLE = ANYTIME;
}
{
        PROPERTY = Thorough_Probe_Interval;
        MIN=1;
        MAX=3600;
        DEFAULT=60;
        TUNABLE = ANYTIME;
}

# The number of retries to be done within a certain period before concluding
# that the application cannot be successfully started on this node.
{
        PROPERTY = Retry_count;
        MAX=10;
        DEFAULT=2;
        TUNABLE = ANYTIME; 
}

# Set Retry_interval as a multiple of 60 since it is converted from seconds
# to minutes, rounding up. For example, a value of 50 (seconds)
# is converted to 1 minute. Use this property to time the number of
# retries (Retry_count).
{
        PROPERTY = Retry_interval;
        MAX=3600;
        DEFAULT=300;
        TUNABLE = ANYTIME;
}

{
        PROPERTY = Network_resources_used;
        TUNABLE = WHEN_DISABLED;
        DEFAULT = "";
}
{
        PROPERTY = Scalable;
        DEFAULT = FALSE;
        TUNABLE = AT_CREATION;
}
{
        PROPERTY = Load_balancing_policy;
        DEFAULT = LB_WEIGHTED;
        TUNABLE = AT_CREATION;
}
{
        PROPERTY = Load_balancing_weights;
        DEFAULT = "";
        TUNABLE = ANYTIME;
}
{
        PROPERTY = Port_list;
        TUNABLE = ANYTIME;
        DEFAULT = ;
}

These resource-property declarations include the TUNABLE attribute. This attribute limits the occasions on which the cluster administrator can change the value of the property with which this attribute is associated. For example, the value AT_CREATION means that the cluster administrator can only specify the value when the resource is created and cannot change the value later.

For most of these properties, you can accept the default values as generated by Agent Builder unless you have a reason to change them. Information about these properties follows. For additional information, see Resource Properties or the r_properties(5) man page.

Failover_mode

Indicates whether the RGM should relocate the resource group or abort the node or zone in the case of a failure of a Start or Stop method.

Thorough_probe_interval, Retry_count, and Retry_interval

Used in the fault monitor. Tunable equals ANYTIME, so a cluster administrator can adjust them if the fault monitor is not functioning optimally.

Network_resources_used

A list of logical host name or shared address resources that are used by the data service. Agent Builder declares this property so that a cluster administrator can specify a list of resources, if there are any, when the cluster administrator configures the data service.

Scalable

Set to FALSE to indicate that this resource does not use the cluster networking (shared address) facility. If you set this property to FALSE, the resource type property Failover must be set to TRUE to indicate a failover service. See Transferring a Data Service to a Cluster and Implementing Callback Methods for additional information about how to use this property.

Load_balancing_policy and Load_balancing_weights

Automatically declares these properties. However, these properties have no use in a failover resource type.

Port_list

Identifies the list of ports on which the server is listening. Agent Builder declares this property so that a cluster administrator can specify a list of ports when the cluster administrator configures the data service.