Product Documentation

Define an application

This category consists of the new API which is the starting point of any application module script. It also contains the APIs that let you define the discovery level of the application, define the operations that can be performed on the application and so on.

Description: This API conveys the application type, for example MSSQL, Oracle, SAP, to the Resiliency Platform. This interface is the starting point of any application module script and is mandatory. This initiates the application along with the logger. The logging level is set to Info by default.

To change the log level, use the reset_log API.

See Logging.

Is mandatory: Yes

Input parameter: String : Application type.

Return value: Application object, else undefined.

Syntax:

new VRTS::AppSDK::AppEnablementSDK::Application("<Application Type>");

Example:

my $appObj = new VRTS::AppSDK::AppEnablementSDK::Application("TestApp");

Description: Use this interface to declare the types of discoveries that your application script supports. For the Resiliency Platform to discover the applications, you need to define the discovery types such as deep and probe. Use comma as a delimiter to define more than one discovery level.

Deep and probe discovery types are mandatory.

Is mandatory: Yes

Input parameter: String : Discovery level type, value must be "DEEP" and "PROBE".

Return value: 0 if successful, else any positive number.

Example:

my $appObj = new VRTS::AppSDK::AppEnablementSDK::Application("TestApp");
$appObj->set_discovery_types("DEEP", "PROBE"); 

Description: Use this interface to provide a list of operations that a particular application module script supports. For example, start an application and stop an application. Use comma as a delimiter to define more than one operation type. This interface is mandatory for the Resiliency Platform to execute the discovery script and perform operations on the applications.

Start and stop operations are mandatory.

Is mandatory: Yes

Input parameter: String: Operations types, value must be "START" and "STOP".

Return value: 0 if successful, else any positive number.

Example:

my $appObj = new VRTS::AppSDK::AppEnablementSDK::Application("TestApp");
$appObj->set_operation_types("START", "STOP"); 

Description: Use this interface to register the discovery operation callback function against the discovery operation type defined using the set_discovery_types API. The registered callback function is invoked only when the application module script is invoked with said discovery operation. This is a mandatory interface that conveys the Resiliency Platform the sub-routine which is capable of executing the operation and returning an appropriate return code and return message.

Ensure that the discovery script continues to discover the application in offline mode. Else, when the application is offline it is not discovered, and hence the instance is removed from the Resiliency Platform console. The resiliency group created using the instance becomes invalid.

The callback function is a sub-routine which is defined in the application module script and is capable of executing a said discovery operation successfully. The callback function returns 0 if the said operation is executed successfully else returns any positive number to indicate failure. Along with the return code you can also return a string containing either the success or the failure message. Providing a return code is mandatory otherwise the operation is considered as failed. Providing a return message is optional.

Is mandatory: Yes

Input parameter: String: Discovery operation - the discovery operation name which is previously set using the set_discovery_types API.

Input parameter: Callback function reference - the reference of the sub-routine which is defined in the application module script.

Return value: 0 if successful, else any positive number.

Example:

my $appObj = new VRTS::AppSDK::AppEnablementSDK::Application("TestApp");
if(defined $appObj)
{
	$appObj->set_discovery_types("DEEP, PROBE");
	$ret=$appObj->register_discovery_callback("PROBE",\&probe);
	$ret=$appObj->register_discovery_callback("DEEP",\&deep);
}

sub probe
{

	# Write the code here to discover all application instances

	my $inst_name = "app_inst";
	$appObj->log(LOGLEVEL_DEBUG,"Application instance name: [$inst_name]");
	
	# Write the code here to discover state of each application instance
	
	# Report the state of the discovered application instance 
	# on the Resiliency Platform.
	my $inst = $appObj->add_application_inst($inst_name);
	if (defined $inst)
	{
		# The state must be reported either 'online' or 'offline'
		$inst->set_property(APP_INST_STATE, "Online");
	}

	# return 0 for successful and 1 for failure
	return 0,"probe is successful";
}

Description: Use this interface to register the callback function against the operation type defined using the set_operation_types API. The registered callback function is invoked only when the application module script is invoked with said operation. This is a mandatory interface that conveys the Resiliency Platform the sub-routine which is capable of executing the operation and returning an appropriate return code and return message.

The callback function is a sub-routine which is defined in the application module script and is capable of executing a said operation successfully. The callback function returns 0 if the said operation is executed successfully else returns any positive number to indicate failure. Along with the return code you can also enter a string containing either the success or the failure message. Providing a return code is mandatory otherwise the operation is considered as failed. Providing a return message is optional.

The callback function when registered with AppEnablementSDK using any of the above APIs receives an hashref as a parameter. The hashref parameter contains INSTANCE_NAME as a key and application instance name as a value.

Is mandatory: Yes

Input parameter: String : Operation - The operation name which is previously defined using set_operation_types API.

Callback function reference - the reference of the sub-routine which is defined in the application module script.

Return value: 0 if successful, else any positive number.

Example:

my $appObj=new VRTS::AppSDK::AppEnablementSDK::Application("TestApp");
if(defined $appObj)
{
	$appObj->set_operation_types("START,STOP");
	$ret = $appObj->register_operation_callback("START",\&start);
	$ret = $appObj->register_operation_callback("STOP",\&stop);
}

sub start
{
	my ($arg) = @_;
	
	my $FuncName = ( caller 0 )[3];
	$appObj->log(LOGLEVEL_DEBUG,"Inside $FuncName");
	
	my $inst_name = $arg->{INSTANCE_NAME};
	$appObj->log(LOGLEVEL_DEBUG,"Application instance name: [$inst_name]");
	
	# Write the code here to start an application instance
	# and return appropriate status code and message.
	# Return 0 for successful and 1 for failure
	
	return 0, "Start is successful";
}