OpenShift Cookbook

Book Image

OpenShift Cookbook

By : Shekhar Gulati

Book Image

OpenShift Cookbook

By: Shekhar Gulati

Overview of this book

OpenShift Cookbook

OpenShift Cookbook

Credits

About the Author

About the Author

About the Reviewers

About the Reviewers

www.PacktPub.com

www.PacktPub.com

Preface

Free Chapter

Getting Started with OpenShift

Getting Started with OpenShift

A brief introduction into OpenShift

Creating an OpenShift Online account

Creating OpenShift domains using the web console

Creating a WordPress application using the web console

Uploading SSH keys using the web console

Working with the SSH key passphrases

Cloning the application to the local machine

Deploying your first change

Checking the application's gear quota and limits

Installing the OpenShift rhc command-line client

Setting up an OpenShift account using rhc

Enabling the autocomplete feature in an rhc command-line client

Viewing the account details using rhc

Specifying a different OpenShift server hostname

Managing Domains

Managing Domains

Creating a domain using rhc

Renaming a domain using rhc

Viewing domain details using rhc

Adding viewer members to a domain using rhc

Adding an editor member to a domain using rhc

Adding an admin member to a domain using rhc

Viewing all the members in a domain using rhc

Removing members from a domain using rhc

Restricting gear sizes for a domain using rhc

Leaving a domain using rhc

Deleting a domain using rhc

Creating and Managing Applications

Creating and Managing Applications

Creating an OpenShift application using the rhc command-line client

Specifying your own template Git repository URL

Starting/stopping/restarting an application

Adding and managing add-on cartridges

Adding a cron cartridge to an application

Using downloadable cartridges with OpenShift applications

Viewing application details

Cloning the application Git repository using rhc

SSH into the application gear using rhc

Running a command in the application's SSH session using rhc

Setting application-specific environment variables

Taking and restoring application backups

Tracking and rolling back application deployments

Configuring the default Git branch for deployment

Doing manual deployments

Configuring and doing binary deployments

Using your own custom domain name

Cleaning up the application

Deleting the application

Using MySQL with OpenShift Applications

Using MySQL with OpenShift Applications

Adding a MySQL cartridge to your application

Adding a phpMyAdmin cartridge to your application

Accessing a MySQL database from your local machine

Connecting to a MySQL cartridge from your local machine using MySQL Workbench

Updating the MySQL max connections setting

Updating the MySQL configuration settings

Performing scheduled MySQL database backups

Using an Amazon RDS MySQL DB instance with OpenShift

Using PostgreSQL with OpenShift Applications

Using PostgreSQL with OpenShift Applications

Adding the PostgreSQL cartridge to your application

Accessing the PostgreSQL cartridge from your local machine

Connecting to the PostgreSQL cartridge using pgAdmin from your local machine

Updating the PostgreSQL max_connections setting

Using the .psqlrc configuration file to configure the OpenShift application psql shell

Performing scheduled PostgreSQL database backups

Using EnterpriseDB PostgreSQL Cloud Database with OpenShift

Installing PostgreSQL extensions

Using MongoDB and Third-party Database Cartridges with OpenShift Applications

Using MongoDB and Third-party Database Cartridges with OpenShift Applications

Adding a MongoDB cartridge to your application

Adding a RockMongo cartridge to your application

Accessing a MongoDB cartridge from your local machine

Connecting to a MongoDB cartridge using Robomongo from your local machine

Enabling the MongoDB cartridge REST interface

Performing scheduled MongoDB database backups

Using MongoLab MongoDB-as-a-Service with OpenShift

Adding a MariaDB cartridge to your application

Adding a Redis cartridge to your application

OpenShift for Java Developers

OpenShift for Java Developers

Creating and deploying Java EE 6 applications using the JBoss EAP and PostgreSQL 9.2 cartridges

Configuring application security by defining the database login module in standalone.xml

Installing modules with JBoss cartridges

Managing JBoss cartridges using the management web interface and CLI

Creating and deploying Spring applications using the Tomcat 7 cartridge

Taking thread dumps of Java cartridges

Choosing between Java 6 and Java 7

Enabling hot deployment for Java applications

Skipping the Maven build

Forcing a clean Maven build

Overriding the default Maven build command

Installing the JAR file not present in the Maven central repository

Developing OpenShift Java applications using Eclipse

Using Eclipse System Explorer to SSH into the application gear

Debugging Java applications in the Cloud

OpenShift for Python Developers

OpenShift for Python Developers

Creating your first Python application

Managing Python application dependencies

Creating and deploying Flask web applications using Python and PostgreSQL cartridges

Enabling hot deployment for Python applications

Forcing a clean Python virtual environment

Accessing an application's Python virtual environment

Using Gevent with Python applications

Installing a custom Python package

Using the .htaccess file to configure Apache

OpenShift for Node.js Developers

OpenShift for Node.js Developers

Creating your first Node.js application

Configuring Node supervisor options

Managing Node.js application dependencies

Using the use_npm marker

Enabling hot deployment for Node.js applications

Creating and deploying Express web applications using Node.js and MongoDB cartridges

Working with Web Sockets

Using CoffeeScript with OpenShift Node.js applications

Continuous Integration for OpenShift Applications

Continuous Integration for OpenShift Applications

Adding Jenkins CI to your application

Increasing the slave idle timeout

Installing Jenkins plugins

Using Jenkins to build projects hosted on GitHub

Creating a Jenkins workflow for your OpenShift applications

Upgrading Jenkins to the latest version

Logging and Scaling Your OpenShift Applications

Logging and Scaling Your OpenShift Applications

Viewing application logs

Working with JBoss application logs

Enabling JBoss access logs

Working with Tomcat application logs

Working with Python application logs

Creating scalable applications

Configuring a different health check URL for HAProxy

Configuring HAProxy to use a different balance algorithm

Creating scalable apps from nonscalable apps

Enabling manual scaling with marker files

Running OpenShift on a Virtual Machine

Running OpenShift on a Virtual Machine

Index

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Taking thread dumps of Java cartridges

In this recipe, you will learn how to take thread dumps of your Java cartridge applications. A thread dump lists all the Java threads that are currently active in a Java Virtual Machine (JVM). It can help you understand the state of every thread in the JVM at a particular point in time. It gives you a snapshot of exactly what's executing at a moment in time. Thread dumps are very useful to debug a deadlock condition or to understand resource usage.

Note

This command will work with all the four supported Java cartridges (Apache Tomcat 6, Apache Tomcat 7, JBoss AS7, and JBoss EAP).

Getting ready

This recipe will request for a thread dump of the application created in the Creating and deploying Java EE 6 applications using the JBoss EAP and PostgreSQL 9.2 cartridges recipe. So, please refer to the aforementioned recipe before continuing with this recipe.

How to do it…

Perform the following steps to take a thread dump of your Java application:

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