posted by fhanik on May 1, 2012 07:13 AM

With the Apache Tomcat 7.0.27 release, the Apache Tomcat team introduced a WebSocket implementation. In a previous post, we took a look at what the WebSocket implementation means, including what benefits and limitations they present. Today, we will discuss specifically how WebSocket is implemented in Apache Tomcat 7.

Since WebSocket is a protocol sent over TCP after an initial HTTP handshake, you could effectively implement WebSocket using Tomcat’s Comet implementation. There is a back port to Tomcat 6 suggested that does exactly that with very minor changes.

The Apache Tomcat team however decided to go with a more substantial implementation with changes to the core of Tomcat’s network and protocol implementation. The reason for this was memory and scalability based. If Tomcat can recycle the HttpServletRequest/Response objects after the initial handshake, each WebSocket connection will take up less memory in the Java heap. It also opens up the Tomcat container for other future protocols that utilize the HTTP Upgrade feature.

The WebSocket implementation from an API standpoint is fairly straightforward. You really can only do two things:

1. Send messages
2. Receive messages

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posted by fhanik on April 23, 2012 10:22 PM

With the 7.0.27 release the Apache Tomcat team introduced a WebSocket implementation. WebSocket has received a lot of hype, and has been much anticipated by Tomcat users. Let’s take a quick look at what web sockets are, what benefits and limitations they have and how they are implemented in Apache Tomcat 7.

What is a WebSocket?

WebSocket is considered the next step in evolution of web communication. Over time, communication has evolved in steps to reduce the time and data throughput for the application to update a user’s browser. The evolution has looked a little like this:

• Entire page reloads
• Component reloads using AJAX Processing
• Comet communication
  • Long poll– similar to AJAX, but not holding a thread on the server
  • Bi directional- two way communication over the same TCP

Each of these steps had their benefits and challenges. Apache Tomcat 6 implements bi-directional communication over HTTP using its Comet Processor. This implementation allowed for asynchronous event driven request processing as well as bi-directional communication. This implementation had a few limitations.

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posted by Stacey Schneider on April 5, 2012 01:59 PM

The Apache Tomcat team announces the immediate availability of Apache Tomcat 7.0.27

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This release is includes significant new features as well as a number of bug fixes compared to version 7.0.26. The notable changes include:

• Support for the WebSocket protocol (RFC6455). Both streaming and message based APIs are provided and the implementation currently fully passes the Autobahn test suite. Also included are several examples.
• A number of fixes to the HTTP NIO connector, particularly when using Comet.
• Improve the memory leak prevention and detection code so that it works well with JVMs from IBM.

Please refer to the change log for the complete list of changes:
http://tomcat.apache.org/tomcat-7.0-doc/changelog.html

Note that this version has 4 zip binaries: a generic one and three bundled with Tomcat native binaries for Windows operating systems running on different CPU architectures.

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posted by jfullam on March 20, 2012 04:32 PM

Working software is the primary measure of progress for software development teams. This is one of the principles of the Agile Manifesto and has led agile software teams to focus on implementing the most important features of a system early and efficiently. These teams usually provide frequent deployments of the software in order to receive feature validation from the business and to show project progress. The benefits are quick and frequent feedback for the developers and congruous applications for the business.

The practice of automated continuous deployment ensures that the latest checked in code is deployed, running, and accessible to various roles within an organization. Project managers can have a place to check on project progress, testers have a view into the latest builds, developers can see the their modules working with the modules from other team members, and stakeholders can see how their requirements have been translated into working software. As some of the most popular application servers to deploy agile applications on, Apache Tomcat and tc Sserver easily integrate with continuous integration servers to allow agile teams to realize continuous deployment while utilizing a lean application server (another practice of agile teams).

You can start practicing continuous deployment very quickly using Apache Tomcat or VMware vFabric tc Server, Jenkins, and your source control system of choice. For this article, since another tenet of agile development is to instrument the application early for better manageability, in addition to outlining how to set up continuous deployment with Tomcat, we will include alternative instructions for tc Server which has built-in monitoring from VMware vFabric Hyperic.

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posted by Stacey Schneider on February 22, 2012 10:48 AM

The Apache Tomcat team announces the immediate availability of Apache Tomcat 7.0.26

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This release is primarily a bug fix release and includes numerous bug fixes compared to version 7.0.25. The notable bug fixes include:

• Improved @HandlesTypes processing which no longer loads all classes on web application start.
• Ensure that POST bodies are available for reply after FORM authentication when using the AJP connectors
• Corrected a regression that broke annotation scanning for many use cases including web applications packaged as WARs and many embedded scenarios.

Please refer to the change log for the complete list of changes:
http://tomcat.apache.org/tomcat-7.0-doc/changelog.html

Note that this version has 4 zip binaries: a generic one and three bundled with Tomcat native binaries for Windows operating systems running on different CPU architectures.

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posted by dmikusa on January 23, 2012 03:14 PM

One of the new features with Tomcat 7 is a replacement to the commons-dbcp connection pool. While the commons-dbcp connection pool works fine for small or low traffic applications, it is known to have problems in highly concurrent environments (think multi-core/multi-cpu).

Fortunately, this is where the JDBC Connection Pool excels. It is a completely new connection pool which has been written from the ground up, with a focus on highly concurrent environments and performance.

Given its focus on high concurrency and performance, many users are finding that the JDBC Connection Pool can be great for use in a production environment. This article will discuss the features and options which make using the JDBC Connection Pool a great choice.

The Basics

Getting started with the JDBC Connection Pool is very simple. It was purposefully designed as a drop-in replacement for commons-dbcp and as such, if you've ever used commons-dbcp you'll be immediately familiar with the configuration for the JDBC Connection Pool.

This means the most existing commons-dbcp users can switch to the JDBC Connection Pool by simply adding the following property to their configuration factory=”org.apache.tomcat.jdbc.pool.DataSourceFactory”.

What about the other commons-dbcp configuration options? You don't need to change them at all. Virtually all of the commons-dbcp configuration options are supported by the JDBC Connection Pool. Including but not limited to: testWhileIdle, testOnBorrow, testOnReturn, maxActive, minIdle, maxWait, initialSize, removeAbandoned, removeAbandonedTimeout and logAbandoned.

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posted by Stacey Schneider on January 23, 2012 10:47 AM

The Apache Tomcat team announces the immediate availability of Apache Tomcat 7.0.25

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This release includes numerous bug fixes and several new features compared to version 7.0.23. The notable new features include:

• Align the Servlet 3.0 implementation with the changes defined in the first maintenance release (also known as Rev. A.). See the JCP documentation for a detailed list of changes.
• Add support for connectors to automatically select a free port to bind to. This is useful when embedding and for testing.
• Update to Commons Pool 1.5.7, Commons Daemon 1.0.8 and Eclipse JDT compiler 3.7.1.

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posted by Stacey Schneider on January 4, 2012 07:31 AM

2011 has been a great year for the Tomcat Expert community. After almost 2 years of operating, the Tomcat Expert has hit its stride, unloading an array of new information, as well as keeping you up to date with the newest releases for Apache Tomcat 6 and Apache Tomcat 7. With the addition of two new Tomcat Expert Contributors, (Channing Benson and Daniel Mikusa), the Tomcat Expert community continues to build on its reputation for being the leading source for fresh perspectives and new information on how to best leverage Apache Tomcat in the enterprise.

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posted by chanthing on December 21, 2011 05:48 AM

1. Introduction

My last article for Tomcat Expert described various aspects of the Valve construct of Apache Tomcat: some basics about how to implement and configure a valve and an example of where things could go wrong if you were unaware of the operational details. For those of you who don’t remember (or didn’t read the article in the first place), the key takeaway was that because Tomcat valves are maintained as a chain, the order in which the valves are added to the configuration (typically in conf/server.xml) is significant, and the code that implements the filter must conclude with a call to invoke the next filter in the chain.

This time we’re going to lighten things up a bit with a general survey of what valves are available and how one might put them to use. Given the imminent arrival of the winter holiday season, one might think of it as the Apache Tomcat Valve Gift Catalog. Peruse it and find just the right gift for your favorite Tomcat administrator.

For each valve, I’ll describe its functionality, the most important configuration parameters, and point out any configuration subtleties that might not be apparent from the stock documentation. that can be found at http://tomcat.apache.org/tomcat-7.0-doc/config/valve.html. If there are any less well-known attributes or “secret” parameters associated with the valve, I’ll describe them.

2. Request Logging

2.1 Access Log Valve

The AccessLogValve can be configured at the context, host, or engine level and will log requests made to that container to a file. Attributes of AccessLogValve control the directory, the filename, and the format of the data to be written, including the ability to write information about headers (incoming and outgoing), cookies, and session or request attributes.

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posted by Stacey Schneider on December 6, 2011 12:09 PM

The Apache Tomcat team announces the immediate availability of Apache Tomcat 6.0.35 stable.

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Apache Tomcat 6.0.35 is primarily a security and bug fix release. All users of older versions of the Tomcat 6.0 family should upgrade to 6.0.35.

Note that is version has 4 zip binaries: a generic one and three bundled with Tomcat native binaries for different CPU architectures.

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