Analyzing Disk Space problems.

Products

• CA Application Performance Management Agent (APM / Wily / Introscope)
• INTROSCOPE

Issue/Introduction

 Introduction: 

  In production environments, applications can become unavailable due to failures to correct mount disk volumes or through disk capacity being completely used (leading to out of space errors).

  A perl script (DiskSpace.txt - attached below) was created to help detect significant changes in capacity on servers where critical components for the web infrastructure execute.

  This enables operations to quickly identify disk resource shortages that could lead to failures unless they are quickly addressed.

  This example shows all the mounts and the percentage of capacity.

 

 

 Instructions: 

Collected Metrics

The DiskSpace.pl script returns the name of the mount and the capacity used as a percentage.

 

The fully qualified metric name is SuperDomain|hostname|EPAgentProcess|EPAgent|Diskspace:Capacity/mountname

One entry will be returned for each disk that is mounted on the server.

 

Element	Description	Type
Capacity/mountname	The name of the mount point and the percentage of capacity used.	Integer

EPA Definition

The DiskSpace.pl script is delivered as a perl script, which requires no arguments.

 

The following is an example of the stateless EPA definition for the provided DiskSpace.pl script.

 

 

  introscope.epagent.plugins.stateless.names=DISKSTATS

  introscope.epagent.stateless.DISKSTATS.command=perl ./config/linux /DiskSpace.pl

  introscope.epagent.stateless.DISKSTATS.delayInSeconds=900

 

Design Assumptions

The perl script uses strings to match the standard output to known strings in the output of server-status and strings to locate the substring position of data used in the Introscope metric.

 

This means if the output of the DiskSpace.pl changes due to configuration differences that perl should tolerate these environmental differences.

 

If the perl script requires alteration, then a number of variables are available to provide the matching criteria. These are:

 

Variable	Description
$match	Matching string that must be found in the output
$type	The metric type which will be returned from the EPAgent
$name	This defines the name hierarchy  of the metric

Prerequisites

This script requires the following items to be available within the environment.

 

1.  - Perl
2.  - Wily Introscope EPAgent
3.  - Ability to issue the system command df -k.

 

Additional Information:  

•    After downloading the script from this article, please modify the script name from DiskSpace.txt to DiskSpace.pl as this is a Perl script.
•    This document was created to help you with your customization.  Any further help related to this Knowledge Document must be addressed by CA Professional Services.

Environment

Release:
Component: APMAGT