Sun Cluster Data Services Developer's Guide for Solaris OS

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, as well as the paths to each of the callback methods. Resource Type Properties 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. Resource Properties 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 that the cluster administrator registers the data service with the Sun Cluster software.

Use Agent Builder to generate the RTR file for your data service. Agent Builder declares the set of properties that are both useful and required for any data service. For example, particular properties, such as Resource_type, must be declared in the RTR file. Otherwise, registration of the data service fails. Other properties, although not required, are not available to a cluster administrator unless you declare them in the RTR file. Some properties are available whether you declare them or not because the RGM defines them and provides default values. To avoid this level of complexity, use Agent Builder to guarantee the generation of a correct RTR file. Later, you can edit the RTR file to change specific values if necessary.

The rest of this section shows a sample RTR file, which was created by Agent Builder.

Declaring Resource Type Properties

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

Note –

Only a cluster administrator can configure the resource type property Installed_nodes. You cannot declare Installed_nodes in the RTR file.

The syntax of resource type declarations is as follows:

property-name = value;

Note –

Property names for resource groups, resources, and resource types are not case sensitive. You can use any combination of uppercase and lowercase letters when you specify property names.

These are 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 fails.

The first set of resource type declarations provide basic information about the resource type.

Resource_type and Vendor_id

Provide a name for the resource type. You can specify the resource type name with the Resource_type property alone (smpl) or by using the Vendor_id property as a prefix with a period (.) separating it from the resource type (SUNW.smpl), as shown in the sample. If you use Vendor_id, make it the stock market symbol of the company that is defining the resource type. The resource type name must be unique in the cluster.

Note –

By convention, the resource type name (vendoridApplicationname) is used as the package name. Starting with the Solaris 9 OS, the combination of vendor ID and application name can exceed nine characters.

Agent Builder, on the other hand, in all cases explicitly generates the package name from the resource type name, so it enforces the nine-character limit.

RT_description

Briefly describes the resource type.

RT_version

Identifies the version of the sample data service.

API_version

Identifies the version of the API. For example, API_version = 2 indicates that the data service can be installed on any version of Sun Cluster starting with Sun Cluster 3.0. API_version = 7 indicates that the data service can be installed on any version of Sun Cluster starting with Sun Cluster 3.2. However, API_version = 7 also indicates that the data service cannot be installed on any version of Sun Cluster that was released before Sun Cluster 3.2. This property is described in more detail under the entry for API_version in Resource Type Properties.

Failover = TRUE

Indicates that the data service cannot run in a resource group that can be online on multiple nodes or zones at the same time. In other words, this declaration specifies a failover data service. This property is described in more detail under the entry for Failover in Resource Type Properties.

Start, Stop, and Validate

Provide the paths to the respective callback method programs that are called by the RGM. These paths are relative to the directory that is specified by RT_basedir.

The remaining resource type declarations provide configuration information.

Init_nodes = RG_PRIMARIES: Specifies that the RGM call the Init, Boot, Fini, and Validate methods only on nodes or zones that can master the data service. The nodes or zones that are specified by RG_PRIMARIES are a subset of all nodes or zones on which the data service is installed. Set the value to RT_INSTALLED_NODES to specify that the RGM call these methods on all nodes or zones on which the data service is installed.
RT_basedir: Points to /opt/SUNWsample/bin as the directory path to complete relative paths, such as callback method paths.
Start, Stop, and Validate: Provide the paths to the respective callback method programs that are called by the RGM. These paths are relative to the directory that is specified by RT_basedir.

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.

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.

Declaring Extension Properties

Extension properties appear at the end of the sample RTR file.

# 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 = 120;
        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 the following extension properties, which are useful for most data services.

Confdir_list: Specifies the path to the application configuration directory, which is useful information for many applications. The cluster administrator can provide the location of this directory when the cluster administrator configures the data service.
Monitor_retry_count, Monitor_retry_interval, and Probe_timeout: Controls the restarts of the fault monitor itself, not the server daemon.
Child_mon_level: Sets the level of monitoring to be carried out by the PMF. See the pmfadm(1M) man page for more information.

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