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Sun Cluster 3.0 U1 Data Services Developer's Guide

Setting Resource and Resource Type Properties

Sun Cluster provides a set of resource type properties and resource properties that you use to define the static configuration of a data service. Resource type properties specify the type of the resource, its version, the version of the API, and so on, as well as paths to each of the callback methods. Table A-1 lists all the resource type properties.

Resource properties, such as Failover_mode, Thorough_probe_interval, and method timeouts, also define the static configuration of the resource. Dynamic resource properties such as Resource_state and Status reflect the active state of a managed resource. Table A-2 describes the resource properties.

You declare the resource type and resource properties in the resource type registration (RTR) file, which is an essential component of a data service. The RTR file defines the initial configuration of the data service at the time the cluster administrator registers the data service with Sun Cluster.

It is recommended that you use Agent Builder to generate the RTR file for your data service because Agent Builder declares the set of properties that are both useful and required for any data service. For example certain properties (such as Resource_type) must be declared in the RTR file or registration of the data service fails. Other properties, though not required, will not be available to a system administrator unless you declare them in the RTR file, while some properties are available whether you declare them or not, because the RGM defines them and provides a default value. To avoid this level of complexity, you can simply use Agent Builder to guarantee generation of a proper RTR file. Later on you can edit the RTR file to change specific values if you need to do so.

The rest of this section leads you through a sample RTR file, created by Agent Builder.

Declaring Resource Type Properties

The cluster administrator cannot configure the resource type properties you declare in the RTR file. They become part of the permanent configuration of the resource type.

Note -

One resource type property, Installed_nodes, is configurable by a system administrator. In fact, it is only configurable by a system administrator and you cannot declare it in the RTR file.

The syntax for resource type declarations is:


property_name = value;
Note -

The RGM treats property names as case insensitive. The convention for properties in Sun-supplied RTR files, with the exception of method names, is uppercase for the first letter of the name and lowercase for the rest of the name. Method names--as well as property attributes--contain all uppercase letters.

Following are the resource type declarations in the RTR file for a sample (smpl) data service:

# Sun Cluster Data Services Builder template version 1.0
# Registration information and resources for smpl
#
#NOTE: Keywords are case insensitive, i.e., you can use
#any capitalization style you prefer.
#
Resource_type = "smpl";
Vendor_id = SUNW;
RT_description = "Sample Service on Sun Cluster";

RT_version ="1.0"; 
API_version = 2;	 
Failover = TRUE;

Init_nodes = RG_PRIMARIES;

RT_basedir=/opt/SUNWsmpl/bin;

START						=		smpl_svc_start;
STOP						=		smpl_svc_stop;

VALIDATE 						=		smpl_validate;
UPDATE 						=		smpl_update;

MONITOR_START 							= 	smpl_monitor_start;
MONITOR_STOP 							= 	smpl_monitor_stop;
MONITOR_CHECK 						= 		smpl_monitor_check;
Tip -

You must declare the Resource_type property as the first entry in the RTR file. Otherwise, registration of the resource type will fail.

The first set of resource type declarations provide basic information about the resource type, as follows:

The remaining resource type declarations provide configuration information, as follows:

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 curly brackets:


{
    Attribute = Value;
    Attribute = Value;
             .
             .
             .
    Attribute = Value;
}

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

You can also define new resource properties in the RTR file--so-called extension properties--using a set of property attributes provided by Sun Cluster. Table A-4 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. Resource properties are configurable by system administrators, within limits defined by the property attributes in the RTR file. For example, the default value for each method timeout in the sample is 300 seconds. An administrator can change this value; however, the minimum allowable value, specified by the MIN attribute, is 60 seconds. See Table A-4 for a complete 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 = AT_CREATION;
        DEFAULT = ;
}

These resource-property declarations add the TUNABLE attribute, which limits the occasions on which the system administrator can change their values. AT_CREATION means the administrator can only specify the value when the resource is created and cannot change it 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):

Declaring Extension Properties

At the end of the sample RTR file are extension properties, as shown in the following listing

# Extension Properties
#

# The cluster administrator must set the value of this property
to point to the 
# directory that contains the configuration files used by the application. 
# For this application, smpl, specify the path of the configuration
file on 
# PXFS (typically named.conf).
{
	PROPERTY = Confdir_list;
	EXTENSION;
	STRINGARRAY;
	TUNABLE = AT_CREATION;
	DESCRIPTION = "The Configuration Directory Path(s)";
}

# The following two properties control restart of the fault monitor.
{
        PROPERTY = Monitor_retry_count;
        EXTENSION;
        INT;
        DEFAULT = 4;
        TUNABLE = ANYTIME;
        DESCRIPTION = "Number of PMF restarts allowed for fault
monitor.";
}
{
        PROPERTY = Monitor_retry_interval;
        EXTENSION;
        INT;
        DEFAULT = 2;
        TUNABLE = ANYTIME;
        DESCRIPTION = "Time window (minutes) for fault monitor restarts.";
}
# Time out value in seconds for the probe.
{
        PROPERTY = Probe_timeout;
        EXTENSION;
        INT;
        DEFAULT = 30;
        TUNABLE = ANYTIME;
        DESCRIPTION = "Time out value for the probe (seconds)";
}

# Child process monitoring level for PMF (-C option of pmfadm).
# Default of -1 means to not use the -C option of pmfadm.
# A value of 0 or greater indicates the desired level of child-process.
# monitoring.
{
        PROPERTY = Child_mon_level;
        EXTENSION;
        INT;
        DEFAULT = -1;
        TUNABLE = ANYTIME;
        DESCRIPTION = "Child monitoring level for PMF";
}
# User added code -- BEGIN VVVVVVVVVVVV
# User added code -- END   ^^^^^^^^^^^^

Agent Builder creates some extension properties that are useful for most data services, as follows.

You can create additional extension properties in the area delimited by the User added code comments.