JBoss

/Tag: JBoss

ATG License IP Checks on JBoss

Some ATG product licenses are bound to a specific list of IP addresses. However, it may validate that in a somewhat counter-intuitive manner, at least under Linux.

If, for example, you are running ATG within JBoss on a server with multiple IP addresses (or multiple NICs), you might expect that if you bind JBoss to a specific IP address, that will be the IP that is used in the license check, since clearly that is the real IP the server is listening on.

Not so. It appears that instead of checking the IP address(es) of the J2EE container, it looks at the machine’s hostname. So if your hostname is configured to a name that is mapped to a different IP in your /etc/hosts file, your license will fail to validate.

The fix is relatively simple, just change the hostname of the server to match the name mapped to the licensed IP address in your /etc/hosts file, and start up JBoss again.

However, since this essentially alters the “identity” of your server it can have other repercussions on your server. So be warned. It may make more sense to get the licenses issued with IPs matching your hostname, not the actual IP you intend to run JBoss/ATG on.

I think this is a bit of a bug, in my opinion.

JBoss jsessionid Query Parameter Removal

Instead of just using the Apache mod_rewrite rules from my post on “Hiding jsessionid parameters from Google“, which uses redirects, wouldn’t it be better to simply not output the jsessionid parameter into the URLs?

First, what are those jsessionid params, and why are they there?

For a web application to have state, i.e. remember things from one page request to the next (such as that you’re logged in, who you are, what is in your shopping cart, etc…), most web applications have something called a session. The session starts when you hit the website at first, sticks with you while you are on the site, and expires after you have either logged out or have been idle (i.e. not clicked on anything) for a set period of time (perhaps 30 minutes).

In general the actual session data is held on the server, things like your shopping cart, your user profile, all of that. However, in order to associate requests from your web browser with the correct session, your browser needs to pass something for the web application to recognize which session is yours. This is traditionally done in two ways:

firstly and primarily using a session-life browser cookie (or two) which hold a session identifier and optionally some additional security token(s). The browser receives this cookie from the web application, and then sends the cookie back to the web application with each page request. The web application looks at the cookie, and figures out which session is yours, and handles your page request appropriately.

secondly, and usually only as a fall-back for browsers which do not support cookies or whose cookie support has been turned off, is to rewrite every link in the web application which points to another page in the same web application with a special session id added to the URI of the link. This is usually done as a path parameter (following a ‘;’), but sometimes is also done as a query parameter (following a ‘?’).

Since on the first request to a web application, the browser is not sending a session cookie, the web application has no way of knowing if the browser actually supports cookies or not. So for the first page, the web application will usually send back the session cookie AND rewrite all of the links on the page with the jsessionid just in case the cookie is not returned.

So what’s the problem?

Search engine spiders, like Google’s GoogleBot, usually do not support cookies. This means that they see the site with the jsessionid parameter in every link and every requested URL. So this leads to three related problems. First, the links that show up in a Google search include an ugly ‘jsessionid=xxxxxx’ which looks ugly. Second, Google doesn’t recognize that the jsessionid parameter doesn’t change the page content, and as such each time the GoogleBot hits the site, and gets a different jsessionid, it indexes all of the pages again. This leads to getting multiple result listings for the same page in search results. For instance you might see the same page listed 7 times in a row. Third, by having multiple instances of the same page with the same content, the Google PageRank of the actual page is severely diluted and perhaps even penalized due to the multiple presentations.

Because of these problems, we do not want the GoogleBot to see the jsessionid URI parameters.

In my earlier post, linked to above, I used Apache mod_rewrite to look for requests from GoogleBot, and send a redirect back to GoogleBot, redirecting it to the same URI it had initially requested, just stripped of the jsessionid parameter.

This time I’m going to use a Servlet Filter to prevent the jsessionid parameter from being inserted into the URL links on the page for GoogleBot requests. This is more elegant since there are no redirects.

First, I want to link to the web page which provided the starting point for the solution I used: JSESSIONID considered harmful

I took that approach and modified the filter code to only do this for GoogleBot requests, which will allow users who don’t support or allow cookies to still use the site.

I have one Java class: DisableUrlSessionFilter.java

[java] package com.digitalsanctuary.util;

import java.io.IOException;

import javax.servlet.Filter;
import javax.servlet.FilterChain;
import javax.servlet.FilterConfig;
import javax.servlet.ServletException;
import javax.servlet.ServletRequest;
import javax.servlet.ServletResponse;
import javax.servlet.http.HttpServletRequest;
import javax.servlet.http.HttpServletResponse;
import javax.servlet.http.HttpServletResponseWrapper;

/**
* Servlet filter which disables URL-encoded session identifiers.
*
*
* Copyright (c) 2006, Craig Condit. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
*
* * Redistributions of source code must retain the above copyright notice,
* this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright notice,
* this list of conditions and the following disclaimer in the documentation
* and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
* IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
* ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR CONTRIBUTORS BE
* LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
* POSSIBILITY OF SUCH DAMAGE.
*
* Modified by Devon Hillard ([email protected]) to only filter for GoogleBot,
* not for users without cookies enabled.
*
*/
@SuppressWarnings(“deprecation”)
public class DisableUrlSessionFilter implements Filter {

/**
* The string to look for in the User-Agent header to identify the GoogleBot.
*/
private static final String GOOGLEBOT_AGENT_STRING = “googlebot”;

/**
* The request header with the User-Agent information in it.
*/
private static final String USER_AGENT_HEADER_NAME = “User-Agent”;

/**
* Filters requests to disable URL-based session identifiers.
*
* @param pRequest
* the request
* @param pResponse
* the response
* @param pChain
* the chain
*
* @throws IOException
* Signals that an I/O exception has occurred.
* @throws ServletException
* the servlet exception
*/
public void doFilter(final ServletRequest pRequest, final ServletResponse pResponse, final FilterChain pChain)
throws IOException, ServletException {
// skip non-http requests
if (!(pRequest instanceof HttpServletRequest)) {
pChain.doFilter(pRequest, pResponse);
return;
}

HttpServletRequest httpRequest = (HttpServletRequest) pRequest;
HttpServletResponse httpResponse = (HttpServletResponse) pResponse;

boolean isGoogleBot = false;

if (httpRequest != null) {
String userAgent = httpRequest.getHeader(USER_AGENT_HEADER_NAME);
if (StringUtils.isNotBlank(userAgent)) {
if (userAgent.toLowerCase().indexOf(GOOGLEBOT_AGENT_STRING) > -1) {
isGoogleBot = true;
}
}
}

if (isGoogleBot) {
// wrap response to remove URL encoding
HttpServletResponseWrapper wrappedResponse = new HttpServletResponseWrapper(httpResponse) {
@Override
public String encodeRedirectUrl(final String url) {
return url;
}

@Override
public String encodeRedirectURL(final String url) {
return url;
}

@Override
public String encodeUrl(final String url) {
return url;
}

@Override
public String encodeURL(final String url) {
return url;
}
};

// process next request in chain
pChain.doFilter(pRequest, wrappedResponse);
} else {
pChain.doFilter(pRequest, pResponse);
}
}

/**
* Unused.
*
* @param pConfig
* the config
*
* @throws ServletException
* the servlet exception
*/
public void init(final FilterConfig pConfig) throws ServletException {
}

/**
* Unused.
*/
public void destroy() {
}
}[/java]

and the servlet filter configuration in my web.xml file:

[xml]
DisableUrlSessionFilter

com.digitalsantuary.util.DisableUrlSessionFilter

….


DisableUrlSessionFilter
/*
[/xml]

So far, it seems to be working beautifully. It only impacts the GoogleBot, and it successfully strips the jsessionid parameter from the links on the site.

Enjoy!

Hiding jsessionid parameter from Google

If you’re running a website on JBoss you may discover that Google has indexed your pages with a jsessionid query parameter in the links.

The Google crawl bot does not support cookies, therefore JBoss uses the jsessionid query parameter in order to maintain a session state without cookies. These query parameters can impact your Google rank and indexing efficiency as the same page can be indexed multiple times with different session ids, and dilute your ranking. Also, it leads to ugly links.

If you want to still be able to support non-cookie using users, but would like Google to see cleaner links, you can use Apache’s mod_rewrite to modify the links for the Google bot only, leaving the normal functionality available to the rest of your users.

Assuming you have mod_rewrite enabled in your Apache instance, use this configuration in your apache config:

[code]
# This should strip out jsessionids from google
RewriteCond %{HTTP_USER_AGENT} (googlebot) [NC]
ReWriteRule ^(.*);jsessionid=[A-Za-z0-9]+(.*)$ $1$2 [L,R=301]
[/code]
This rule says for request where the user agent contains “googlebot” (with case insensitive matching), rewrite the URL without the jsessionid. It seems to work nicely.

10MinuteMail upgraded again

Moved up to Seam 2.0 CR3, and JBoss 4.2.2. I also optimized some code, got rid of some useless error logging, etc…

Hopefully it will perform a little better:) So far it seems to process incoming e-mail much faster, which was a bottleneck under load.

Enjoy!

Top Ten Tools

I was surfing around today, and saw this article about the top ten tools you use.

As far as getting work done on the computer (I’m taking the computer for granted and not counting it as a tool, although for it all to come together it’s worth noting I use an Apple MacBookPro with 4GB of RAM) my top applications are:

  1. Eclipse: my favorite Java IDE with a good set of plugins (JBoss Tools, MyEclipseIDE, WTP, Mylyn, and others)
  2. iGTD:  a great GTD task manager for the Mac.  I use it for work, personal projects, home errands, etc…  I used to use KinklessGTD in OmniOutliner, but now I swear by iGTD.  The upcoming Omni Focus will have to bring something amazing to the table to get to me to pay to switch.
  3. SSH/SCP/Terminal: I manage and deploy to many servers.  Being able to SSH into them and move files securely is critical.  I’m handy with the command line, bash scripting, and all that, so I end up doing things that way often.
  4. Emacs: I can handle vi, but when I’m on a remote server making changes or looking through files trying to figure something out, Emacs is my favorite tool for the job.
  5. Safari: I spend a lot of time on the web researching, reading, and looking at the applications I’m building.  I also use Camino, but Safari 3 is my favorite browser and is always open.
  6. Adium: I love staying in touch with my friends, family, and co-workers.  Adium lets me keep in touch on AIM, Yahoo, MSN, GTalk, and more in a very nice application.
  7. iTunes: Music helps me get into the zone and keeps me happy.  Plus I like to watch the occasional TV show:)
  8. Pages: as an architect I often have to generate documentation around projects.  I also write letters (yes the non-e-mail kind).  Pages is a great word processor and making professional looking easy to read documents is a snap.
  9. JBoss: JBoss is a fantastic application server.  It’s free, open source, fast, and powerful.
  10. Postgres: Postgres is a database with all the great attributes I listed for JBoss.  I used to use MySQL but at the time I switched it was lacking many critical features (sub-selects, foreign keys, etc..).  After using postgres for a while, I haven’t looked back.

Those are the applications that I have running on my laptop basically 24/7 and I use each of them every single day.

What are yours?  I’m not trying to get into an emacs versus vi flamewar, but I’d like to hear about what applications get you through your day a little easier.