This blog describes how to send automated notifications (after the June-10-2018 update) in case the JMS resources are critical or exhausted using an integration flow.

Automated Notification for Critical or Exhausted JMS Resources

As mentioned in the blog ‘JMS Resources and Size Limits’ limited resources are available on the JMS broker. To get notified as soon as the resources get critical is required to take early actions to avoid runtime issues. This blog describes how to enable the alerting using a simple integration flow.

How to use the Alert Notification Service for Alerting with the OData APIs is described in the blog Automated Notifications via SAP Alert Notification Service for Critical or Exhausted JMS Resources.

Scenario Description

To enable the notification we use the OData APIs for JMS queue monitoring in an integration flow.. These APIs can be consumed via https://<APIUrl>/api/v1 where <tmn> is the address of the tenant management node(Neo) or the address of the API service instance (CF). Here we will use the API for the JMS broker monitoring via https://<APIUrl>/api/v1/JmsBrokers(‘Broker1’) .

Overall scenario looks like this:

The flow is triggered by a timer, fetches the JMS Resource data via OData adapter, evaluates the JMS resource status in a script and send a notification mail if the resources are critical or exhausted.

Let’s create the flow.

Create Integration Flow with Timer Start Event and OData Receiver

Create an integration flow with Start Timer Event. Using Request-Reply step call OData APIs to fetch details of the JMS broker via OData receiver channel. Below find the configuration of OData Receiver channel:

Note, that you need to use Operation Read(Get), enter JmsBrokers(‘Broker1’) as Resource Path and $expand=QueueStates as Query Options.

Read JMS Resources into Properties in Content Modifier

In a Content Modifier step you now read all the JMS resources via XPath into properties:

Create the following properties:

QueueCapacityOK: XPath to /JmsBrokers/JmsBroker/CapacityOk

QueueCapacityError: XPath to /JmsBrokers/JmsBroker/CapacityError

QueueCapacityWarning: XPath to /JmsBrokers/JmsBroker/CapacityWarning

MaxQueues: XPath to /JmsBrokers/JmsBroker/MaxQueueNumber

Queues: XPath to /JmsBrokers/JmsBroker/QueueNumber

Transactions: XPath to /JmsBrokers/JmsBroker/IsTransactedSessionsHigh

Providers: XPath to /JmsBrokers/JmsBroker/IsProducersHigh

Consumers: XPath to /JmsBrokers/JmsBroker/IsConsumersHigh

Capacity: XPath to /JmsBrokers/JmsBroker/Capacity

MaxCapacity: XPath to /JmsBrokers/JmsBroker/MaxCapacity

Evaluate Overall JMS Resource Status via Groovy Script

In a Groovy Script we now calculate the overall JMS resource status. Use the following script code:

import com.sap.gateway.ip.core.customdev.util.Message;
import java.util.HashMap;

def Message processData(Message message) {
    // Get Properties
       map = message.getProperties();
       MaxCapacity = new BigDecimal(map.get("MaxCapacity"));
       Capacity = new BigDecimal(map.get("Capacity"));
       BigDecimal PercentCapacity = Capacity * 100 / MaxCapacity;
       BigDecimal CriticalLimit = MaxCapacity / 100 * 80;
       BigDecimal ExhaustedLimit = MaxCapacity / 100 * 95;       
       MaxQueueNumber = new BigDecimal(map.get("MaxQueues"));
       QueueNumber = new BigDecimal(map.get("Queues"));
       BigDecimal CriticalLimitQueues = MaxQueueNumber - 1;
       
       if (Capacity >= ExhaustedLimit) {
          CapacityStatus = "Exhausted";
       }
       else if (Capacity >= CriticalLimit) {
          CapacityStatus = "Critical";
       }
       else {
          CapacityStatus = "OK";
       }   
       
       if (QueueNumber >= CriticalLimitQueues) {
          QueueStatus = "Critical";
       }
       else {
          QueueStatus = "OK";
       }  
 
       int QueueCapacityWarning = new Integer(map.get("QueueCapacityWarning"));
       int QueueCapacityError = new Integer(map.get("QueueCapacityError"));
       if (QueueCapacityError >= 1) {
          QueueCapacityStatus = "Exhausted";
       }
       else if (QueueCapacityWarning >= 1) {
          QueueCapacityStatus = "Critical";
       }
       else {
          QueueCapacityStatus = "OK";
       }
   
       int Consumers = new Integer(map.get("Consumers"));
       if (Consumers == 1) {
         ConsumerStatus = "Critical";
       }
       else {
         ConsumerStatus = "OK";
       }
       
       int Providers = new Integer(map.get("Providers"));
       if (Providers == 1) {
         ProviderStatus = "Critical";
       }
       else {
         ProviderStatus = "OK";
       }
       
       int Transactions = new Integer(map.get("Transactions"));
       if (Transactions == 1) {
         TransactionStatus = "Critical";
       }
       else {
         TransactionStatus = "OK";
       }   
      
      message.setProperty("PercentCapacity", PercentCapacity);
      message.setProperty("CapacityStatus", CapacityStatus);
      message.setProperty("QueueCapacityStatus", QueueCapacityStatus);
      message.setProperty("QueueStatus", QueueStatus);
      message.setProperty("ConsumerStatus", ConsumerStatus);
      message.setProperty("ProviderStatus", ProviderStatus);
      message.setProperty("TransactionStatus", TransactionStatus);

       if ((CapacityStatus == "Exhausted") || (QueueCapacityStatus == "Exhausted"))  {
         message.setProperty("JMSStatus", "Exhausted");
       }  
       else if ((CapacityStatus == "Critical") || (QueueCapacityStatus == "Critical") || (QueueStatus == "Critical") || (ConsumerStatus == "Critical") || (ProviderStatus == "Critical") || (TransactionStatus == "Critical")) {
         message.setProperty("JMSStatus", "Critical");
        } 
       else {
         message.setProperty("JMSStatus", "OK");
       }
       return message;

}

Check Queue Capacity Status in Router

If you want to get additional information about dedicated message queues in case the queue capacity is critical or exhausted in a Router step check the Queue capacity Status and route to a script doing the detailed analysis for the dedicated queues that are critical or exhausted.

Define Non-XML Expression ${property.QueueCapacityStatus} = ‘OK’ for the branch going to the second Router. Default branch is the branch to the Filter step which is executed if the status is not ‘OK’. In the Filter you define an XPath to the //QueueStates to get the details for all the message queues available in the tenant. Note that you have to select Nodelist as Value Type.

In a Script step evaluate the message queues and return all critical and exhausted message queues as properties QueuesCriticalNames and QueuesExhaustedNames,

import com.sap.gateway.ip.core.customdev.util.Message;
import java.util.HashMap;
import groovy.xml.*;
import java.util.*;
import java.text.SimpleDateFormat;

def Message processData(Message message) {
def body = message.getBody(String.class);

    def SourceMessage                = new XmlParser().parseText(body);
    def QueuesExhausted = "";
    def QueuesCritical = "";

     SourceMessage.QueueState.each {
         value = it.text();
         state = it.State.text()
         name = it.Name.text()
         if ("1".equals(state)) {
             QueuesCritical = QueuesCritical +' '+ name
         }
     }
     
    SourceMessage.QueueState.each {
         value = it.text();
         state = it.State.text()
         name = it.Name.text()
         if ("2".equals(state)) {
             QueuesExhausted = QueuesExhausted +' '+ name
         }
     }

    message.setProperty("QueuesCriticalNames", QueuesCritical);
    message.setProperty("QueuesExhaustedNames", QueuesExhausted);
    return message;
}

Check JMS Status in Router

In the second Router step check the JMS Status and route to the mail receiver in case the JMS resources are critical or exhausted:

Define Non-XML Expression ${property.JMSStatus} = ‘OK’ for the branch going to the End event. Default branch is the branch to the Mail receiver which is executed if the status is not ‘OK’.

Configure Mail Receiver

Now we configure the Mail receiver channel sending out the notification. Configure the mail server and authentication you want to use. In the Mail Attributes define the mail receiver and sender mail address and the Mail Subject and Mail Body:

Subject: JMS Ressources ${property.JMSStatus}

Mail Body:

The JMS Resources on the Cloud Integration tenant are ${property.JMSStatus}.
Overall Queue Capacity Status: ${property.CapacityStatus} (${property.PercentCapacity} Percent)
Capacity Status for Queues: Error: ${property.QueueCapacityError} Queues; Warning: ${property.QueueCapacityWarning} Queues; OK: ${property.QueueCapacityOK} Queues
Queues with Warnings:${property.QueuesCriticalNames}
Queues with Errors: ${property.QueuesExhaustedNames}
Queue Status: ${property.QueueStatus} (${property.Queues} / ${property.MaxQueues} )
Transactions Status: ${property.TransactionStatus}
Consumer Connections Status: ${property.ConsumerStatus}
Provider Connections Status: ${property.ProviderStatus}

Deploy and Run the Integration Flow

Configure the Timer start event to run the flow every day or any other interval that suits your requirements. Deploy the integration flow.

Now you will get a Email as soon as the JMS resources get critical.