Parallel Deployment with Apache Tomcat 7

posted by mthomas on May 31, 2011 07:44 AM

Upgrading web applications can be very expensive if your storefront is the web. Weekend maintenance windows, or downtime in general can give an entire company heartburn. Survey data shows that web application downtime can cost some companies up to $72,000 per minute. Yet the cost of not constantly rolling out new features and bug fixes can equally penalize a company in the competitive online markets today.

Previously, to upgrade an application on Tomcat and avoid downtime, system administrators would have to set up multiple instances of Tomcat and do some very clever stuff with load balancers. This equals extra hardware costs as a permanent part of the company’s infrastructure.

Now with the advent of parallel deployment in Tomcat 7, you can have multiple versions of the same application installed at the same time on a single server. Users with active sessions can continue to use the old application and new users will be routed to the new version. This way, no user sessions will be interrupted, and the old application can gracefully phase out.

Setting Up Parallel Deployment

Parallel deployment is a function of the Context Container. The Context element represents a web application, which in turn specifies the context path to a particular Web Application Archive (WAR) file that is the application logic. Parallel deployment allows you to deploy multiple versions of a web application with the same context path concurrently. When choosing what version of the application for any given request, Tomcat will:

  1. Route new requests to the latest version, so new sessions go to the new application.
  2. If session information is in the request, check the session manager for a matching version, so existing sessions will go to the original application for the request.
  3. If session information is in the request, but the corresponding application is no longer present, it will route to the latest version.

Working Across Clusters

If you have clustered Tomcat, configured using the FarmWarDeployer, you can achieve parallel deployment within that cluster. The FarmWarDeployer is a component which lets you deploy a WAR file across an entire cluster. By placing the WAR file on the designated host, clustered Tomcat will automatically replicate that deployment across every server in the cluster.


Because of the sophistication and cost savings this feature brings to enterprise deployments of Tomcat, this feature, built by VMware’s SpringSource, was initially looked at being part of VMware vFabric's tc Server, but once we got building it, it couldn’t be done cleanly without putting some hooks into Tomcat that didn’t fit naturally into the architecture. After careful consideration of what was best for Apache Tomcat, VMware decided to still fill the need to build this feature out, but donate it to the Apache Tomcat project at large.

Mark Thomas is a Senior Software Engineer for the SpringSource Division of VMware, Inc. (NYSE: VMW). Mark has been using and developing Tomcat for over six years. He first got involved in the development of Tomcat when he needed better control over the SSL configuration than was available at the time. After fixing that first bug, he started working his way through the remaining Tomcat bugs and is still going. Along the way Mark has become a Tomcat committer and PMC member, volunteered to be the Tomcat 4 & 7 release manager, created the Tomcat security pages, become a member of the ASF and joined the Apache Security Committee. He also helps maintain the ASF's Bugzilla instances. Mark has a MEng in Electronic and Electrical Engineering from the University of Birmingham, United Kingdom.


Parallel Deployment with Apache Tomcat 7

Are you saying that it is not available in open source version (Apace Tomcat 7.x)?

After reading this whole

After reading this whole article, I have to say that this is probably one of the most amazing articles that I've read in my lifetime. This is just the perfect article that you've published here. Thanks a lot for this! how to save on your power bill

I am very impressed with the

I am very impressed with the work that the writer has done here. This is, without a doubt, one of the most helpful articles that I have read on this blog. Thanks a lot for writing this article. Spring Forward

I haven’t any word to

I haven’t any word to appreciate this post.....Really i am impressed from this post....the person who create this post it was a great human..thanks for shared this with us.
what is phenq

Thanks for your information,

Thanks for your information, it was really very helpfull..
pool company reviews

The website is looking bit

The website is looking bit flashy and it catches the visitors eyes. Design is pretty simple and a good user friendly interface.
inz residence ec floor plan

I admire this article for the

I admire this article for the well-researched content and excellent wording. I got so involved in this material that I couldn’t stop reading. I am impressed with your work and skill. Thank you so much.

I am unable to read articles

I am unable to read articles online very often, but I’m glad I did today. This is very well written and your points are well-expressed. Please, don’t ever stop writing.
Hitting Drills

I found your this post while

I found your this post while searching for information about blog-related research ... It's a good post .. keep posting and updating information.
West Virginia Mesothelioma Law Firm

I can see that you are an

I can see that you are an expert at your field! I am launching a website soon, and your information will be very useful for me.. Thanks for all your help and wishing you all the success in your business.
new futura price list

Your blog provided us with

Your blog provided us with valuable information to work with. Each & every tips of your post are awesome. Thanks a lot for sharing. Keep blogging..
Plumber in Woodstock, Ga

This is a great inspiring

This is a great inspiring article.I am pretty much pleased with your good work.You put really very helpful information. Keep it up. Keep blogging. Looking to reading your next post.
new futura 4 bedroom

Saving electricity is one of

Saving electricity is one of the best methods to lower your monthly energy bills. Your electricity bill is among the most costly payments that you make every month apart from credit card and home loan. how to save on electricity

thanks for j sharing with

thanks for j sharing with that awesome articles thanks u a lot
rasoio elettrico | regolabarba | ferro da stiro con caldaia | Friggitrice ad Aria | scopa a vapore | ripetitore wifi | ripetitore wifi amplificatore wifi piastra a vapore | miglior aspirapolvere | skateboard elettrico | passeggino leggero | miglior smartphone | tablet per bambini yjn__

Parallel Deployment with Apache Tomcat 7

As per the title of the article, parallel deployment is a feature of Apache Tomcat 7. This may be confirmed by examining the changelog and/or reading the documentation.

koratm226, you can find how

koratm226, you can find how to do it on:

Mark, you probably have to add this information on tomcat documentation, it would be easier and quicker to know how to do it.

Anyway, it's an awesome feature! Congrats!


I did it manually from tomcat 5.5;
Let's see if it works ....

Fernando Franzini - Java Blog

download software mxf

download software mxf converter, convert p2 mxf files from your camcorder. convert mxf files to avi mp4 mov avd

News Greek

It is very good, but look at the information at this address.

I think Apache Tomcat 7 is

I think Apache Tomcat 7 is one of the best web applications in this category. Reading this article I have got some important points regarding this application and also how to set up parallel deployment successfully. Thanks a lot! Projection Glass


como baixar pou infinito I have a similar interest this is my page read everything carefully and let me know what you think. clash of clans triche francais


Their work you will is amazingly readily shown ınside your blog articles; you may be an actual competent. I would prefer to supply an extra blog with the preferred varieties one shown yesterday morning. Require ones own people to look into online world.for a lot of stuff tailor-made article.

Tinder, a dating app for the

Tinder, a dating app for the iPhone, has become so wildly popular in the ... a sophomore at Cornell University who downloaded the app earlier download tinder app

I blog often and I genuinely

I blog often and I genuinely thank you for your content. This great article has truly peaked my interest. I will book mark your site and keep checking for new information about once a week. I opted in for your RSS feed too.
Mortgage Broker Calgary

iptv server

application is no longer present, it will route to the latest version.iptv server

oakley sunglasses

You have attempted to post the same content multiple times.

You have attempted to post the same identical content multiple times, causing your posts to be flagged as potential spam. If this has happened in error, please report this error along with your IP address ( to a TomcatExpert site administrator. We apologize for any inconvenience.

You're so cool! I don't

You're so cool! I don't believe I've truly read anything like this before. So wonderful to discover somebody with some genuine thoughts on this topic. Really.. thanks for starting this up. This site is one thing that is needed on the web, someone with a little originality!
Edmonton Mortgage Broker
Life Insurance Vancouver
Life Insurance Calgary


i am looking to purchase black - white pictures of bulgarian monasteries, framed to be shipped to texas, usa for present, please send me if possible names or sites. click

TOUCH Community Services

Promptly this url might irrefutably end up legendary in between every writing many people, because of diligent articles and reviews and ratings. TOUCH Community Services


The procedure a person does may be very conveniently mirrored in your own articles; that you're an absolute pro. I would really prefer so as to add one other webpage into the endorsed styles everyone provided a while back. Talk to an individual's readership to visit internet.

Personal Injury Lawyer Marietta Ga | Call 678-445-7423

Listed here you'll learn it is important, them offers the link in an helpful webpage:
truck accident attorney marietta ga


Absolutely fantastic posting! Lots of useful information and inspiration, both of which we all need!Relay appreciate your work. SEO Columbus


panic treatment would not mean that you will be required to drive around inside an old lorry with like beads hanging with the mirror personal injury attorneys roswell ga

OC Housing News

I can recommend primarily decent and even responsible tips, as a result view it:
Orange County Real Estate

Jual Laptop Notebook PC HP Lenovo Printer Tinta Toner Epson Mura

For many people this is important, so check out my profile:
jual PC Murah


i am looking to purchase black - white pictures of bulgarian monasteries, framed to be shipped to texas, usa for present, please send me if possible names or sites. leading latina

Watch Latest Pakistani Talk Shows and Dramas Online HD at ViiTV

I recommend only good and reliable information, so see it:
Dawn News


i am looking to purchase black - white pictures of bulgarian monasteries, framed to be shipped to texas, usa for present, please send me if possible names or sites. chewable kamagra


I have read a few of the articles on your website now, and I really like your style of blogging. I added it to my favorites blog site list and will be checking back soon. Please check out my site as well and let me know what you think.


application and new users will be routed to the new version. Buy cyprus cars


Fine place, a an exceptionally amazing webpage that there is at this point, stick to beneficial financial job, shall be to come back. メディプラスゲル


I recommend any content. It's always wonderful to work out you will explain in words from middle and additionally picture quality using this valuable content is quite simply recognized. much more information access websites. viral loop review


Your current tunes can be remarkable. You've got a number of quite accomplished musicians. My spouse and i would like anyone the top involving good results. メディプラスゲル 店舗


Checking any blog may make others just want to come up with a greater number of. I did a fabulous which i was first lovely content by means of. The software most likely conducted for the tier still it’s exceptional. cccam server


That is a good write-up When i viewed on account of write about the item. Really it is what exactly I need to to discover trust with foreseeable future you might go on intended for giving a really fantastic write-up. デトランスα 楽天

Wimpernverlängerung Berlin, Wimpernverdichtung, Sugaring Haarent

So lot to occur over your amazing blog. Your blog procures me a fantastic transaction of enjoyable.. Salubrious lot beside the scene.

Fabulous article. That blog

Fabulous article. That blog post impinges on a whole lot of immediate need conflicts of the contemporary culture. You cannot be uninvolved to help you a lot of these conflicts. It blog post grants ideas and even creative concepts. Highly insightful and even helpful. รับทํารั้วสแตนเลส


Camping is simplest way to experience a natural sight-seeing opportunities of Kenya. A lot of camps will be sited around private preservation areas, when walking plus night moves are established. In any safari, visitors are along with staff affiliates who help in various domains. best diet pills for women


i am looking to purchase black - white pictures of bulgarian monasteries, framed to be shipped to texas, usa for present, please send me if possible names or sites. Google Plus

Very Good Article

Best Email Service

Post new comment

This question is for testing whether you are a human visitor and to prevent automated spam submissions.