Webinar - Building Custom Extensions With AppDynamics

AppDynamics Webinars:Building Custom ExtensionsTodd Radel, Senior Manager – Customer Advocacy

Agenda

• Introduction• Writing a script extension• Writing a Java extension• Using your custom metrics• Best practices

• Office hours

Copyright © 2015 AppDynamics. All rights reserved. 3

About Me

Todd RadelSENIOR MANAGERCUSTOMER ADVOCACY TEAM

• More than 20 years experience in the software industry• Java, .NET, Python, Perl• Author of the Python SDK for AppDynamics REST API• Author of six AppDynamics Extensions: F5, Tibco EMS,

Redis, Keynote, SQL, URL Monitor

[email protected]

+1 (484) 857-2335

tradel

todd.radel

linkedin.com/in/tradel

INTRODUCTION


What is an Extension?

• Plugs in to Machine Agent• Imports additional metrics to AppDynamics


Why Use Extensions?

“I already have Graphite/Nagios/my own custom tools…”

BUT:• Add more color to overall AppDynamics picture• Baseline and alert on custom metrics• Create custom dashboards• Work towards a “single pane of glass”


Example Extensions

• Apache Server Monitor• F5 Monitor• ActiveMQ Monitor

…or build your own!


Use Cases

• Run a SQL query every few minutes to count sales/signups/etc.

• Extract metrics from custom instrumentation• Eliminate redundant tools

SCRIPT EXTENSIONS


Anatomy of a Simple Script Extension

• Script file• monitor.xml – describes the extension


Example

• Write an extension to count the number of files in /var/tmp and alert if there are too many


Simple Extension Script


Script Output

name=Custom Metrics|File Count|count, value=29, aggregator=OBSERVATION, time-rollup=CURRENT, cluster-rollup=COLLECTIVE

• name – path and name of your metric• value – metric value• aggregator – how to handle multiple values in one interval• time-rollup – how to aggregate values over time• cluster-rollup – how to aggregate values over nodes


Metric Aggregation

Aggregation Time Rollup Cluster Rollup

How should the controller handle multiple values in a single minute?

How should values be aggregated over time?

How should values be aggregated across nodes in a tier?

AVERAGEAverage of all reported values in that minute

AVERAGEAverage of all one-minute values

INDIVIDUALAverage of metric values across each node in the tier

SUMSum of all reported values in the minute

SUMSum of all one-minute values

COLLECTIVESum of metric values across each node in the tier

OBSERVATIONLast reported value in the minute

CURRENTLast reported one-minute value


Simple monitor.xml for a Script

”periodic” or “continuous”

script filename


OS-Specific monitor.xml for a Script

JAVA EXTENSIONS


Anatomy of a Java Extension

• Class file or JAR file• Dependent libraries• Configuration file• monitor.xml


Structuring Your Java Code

• Can be a single class• Extend from

com.singularity.ee.agent.systemagent.api.AManagedMonitor• Override and implement execute() method• Call getMetricWriter().printMetric() to send data


Example

• Write an extension to import metrics from the Linux collectd(8) daemon


Sample Execute() Method


Configuring Your Extension

• Task arguments from monitor.xml are sent as first parameter to execute() method public TaskOutput execute(Map<String, String> args, TaskExecutionContext taskExecutionContext) throws TaskExecutionException {

• Configure via external file (e.g. config.yml), read the file during execute()


Monitor.xml for Java


Installation

HTTP LISTENER


When to use the HTTP Listener

• When you don’t have control over the code• When the data collector runs on another machine


Starting Machine Agent with HTTP Listener

java ‑Dmetric.http.listener=true ‑Dmetric.http.listener.port=8000 -jar machineagent.jar


Sending Metric Data


Sending Metrics as JSON

USING CUSTOM METRICS


Locating Your Custom Metrics

Tier name

Node name

Metric path


Create Custom Dashboards


Sample Custom Dashboard


Create Health Rules

BEST PRACTICES


Best Practices

• Make it configurable via monitor.xml or config.yml• Allow a custom metric path• Write portable code• Send output to the machine agent log• Follow our “mavenized” project structure• Post the code on GitHub and encourage pull requests


Increasing the Agent Metric Limit

• If you don’t see all metrics in the controller UI• Check machine agent logs for “metric limit reached”• Add command line options and restart machine agent

• Without custom extensions:java -jar machineagent.jar

• With extensions:java -Xmx256m -Dappdynamics.agent.maxMetrics=10000 -jar machineagent.jar


Publishing Your Extension

• Remove any usernames/passwords/hostnames from configuration files

• Add README.md and LICENSE files• Post the code on GitHub• Create new thread on AppDynamics Community to

announce and publish!


Contents of Your README.md

• Description• Requirements• Installation• Configuration• Metrics Produced• How to Contribute (optional)• History/Release Notes• Screenshots

Webinar - Building Custom Extensions With AppDynamics

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