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Monitoring APIs with OMEGAMON for JVM

By Will Meyerink posted Tue August 11, 2020 04:42 AM

  

Introduction

An organization’s APIs are the public face of the enterprise or public agency, and users of the APIs expect consistent results and response times. In this article we provide an overview of how OMEGAMON for JVM can be used to monitor the status of a z/OS Connect EE API workload.

OMEGAMON for JVM

OMEGAMON for JVM on z/OS is a member of the OMEGAMON family of products designed specifically to collect and analyze performance metrics for z/OS-based JVMs. It provides metrics on a range of JVM data points including garbage collection, Java heap usage, native memory usage, threading, locks and CPU usage (including zIIP offload).

Using these metrics, OMEGAMON can warn operations staff and application owners if a JVM is performing sub optimally, which may be having an impact on throughput, response time, or service availability. It can quickly raise alerts to Java-related performance issues that allow corrective action to be taken on the root cause before problems affect business processes.

OMEGAMON for JVM V5.4.0 introduced specific support for monitoring z/OS Connect services. Recent changes in OMEGAMON for JVM V5.4.0 SPE1 have provided extended request monitoring capabilities, including a monitoring view of:

  • APIs deployed to a z/OS Connect EE server
  • Services deployed to a z/OS Connect EE server
  • Systems of Record (SoR) connected to from a z/OS Connect EE server, for example, a CICS system
  • SoR resources accessed by a z/OS Connect EE server, for example, an IMS transaction

To enable OMEGAMON for JVM monitoring of APIs and services, you need to take the following actions:

  • Define the OMEGAMON JVM product extension to z/OS Connect.
  • Configuring the z/OS Connect EE server for OMEGAMON JVM resource monitoring, including:
    1. Update the JVM options.
    2. Configure the OMEGAMON z/OS Connect interceptor.
    3. Define an MVS logstream.

For more information on setting up monitoring see Configuring z/OS Connect for extended request monitoring.

Note: Extended request monitoring requires z/OS Connect EE V3.0.18.

Monitoring APIs

The ‘top level’ OMEGAMON for JVM views allow operations staff to see a quick health status of z/OS Connect EE. For example, Figure 1 shows a top level view of the APIs deployed to a z/OS Connect EE server.


Figure 1 API view

Figure 1 shows the catalog and phonebook APIs. It shows request counts for the different HTTP methods used to invoke each API, for example, the catalog API is invoked using the GET and POST methods. It also shows that there are no errors. You can specify the duration or time range for which you want to see monitoring data.

You can configure OMEGAMON for JVM to alert operations staff to certain situations, for example, for error HTTP response codes, timeouts and long response times. Look out for a follow on article with more information on how to identify the root cause of API response time issues.

Monitoring services

The services ‘top level’ view shows the services deployed to a z/OS Connect EE server. Figure 2 shows the request counts, error counts and response times for the 5 services deployed to the server.

Figure 2 Services view

OMEGAMON for JVM helps you to break down total response time (Resp Time) into the time spent in the z/OS Connect server (zOSConnect Time) and the time spent waiting for a response from the SoR. The time spent waiting for the SoR to respond is Resp Time minus zOSConnect Time.

Monitoring requests to the Systems of Record

The SoR ID ‘top level’ view shows the backend systems that the z/OS Connect EE server is connecting to in order to access resources (programs and data). Figure 3 shows that the z/OS Connect EE server is connecting to an IMS system and a CICS system.


Figure 3 SoR view

  • For the CICS service provider, the SoR ID is the fully qualified CICS applid.
  • For the IMS service provider, the SoR is the IMS datasource name.

Monitoring connections

The Reference ‘top level’ view provides a different view of the backend systems indexed by the connection defined in the server.xml configuration file. Figure 4 shows that the z/OS Connect EE server is processing API requests that use 2 different connection references.


Figure 4 Connections view

Monitoring SoR resources

The SoR resources ‘top level’ view shows the backend resources that are used by the z/OS Connect EE server. Figure 5 shows the request counts, error counts and response times for the 4 resources that are accessed by the server.


Figure 5 SoR resources view

  • For the CICS service provider, the SoR resource consists of the CICS trans ID and program name.
  • For the IMS service provider, the SoR resource is the IMS trans ID.

Summary

This article gives an example of how OMEGAMON for JVM can be used to monitor z/OS Connect EE server APIs. In a follow on article Using OMEGAMON for JVM to diagnose z/OS Connect EE API failures we show how to identify the target service, SoR and resource when there is a problem with a specific API.

More information

More information on monitoring z/OS Connect EE APIs with OMEGAMON for JVM can be found in the OMEGAMON for JVM documentation.

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