I am using a profiling tool, which gets loaded as and when I startup Tomcat with the application war file placed in the webapps directory. So once I run startup, my classes get instrumented and everything works fine.
But for this, I am taking the war file generated as part of maven install ( which downloads tomcat and deploys the war file in it) , and placing it in another tomcat which I have downloaded manually. Then I need to do some editing in the catalin.bat file, to set the JAVA_OPTS property to the javaagent so that it gets started on startup.
What I would like to do is, setup the tool and integrate it with maven such that on a clean and install, the classes gets instrumented and the profiling tool starts running. I believe we can do some configuration changes in pom.xml to achieve this? Any help in this regard would be greatly appreciated! Thanks
This is only part of what you need, but you should configure your tomcat in a different way - maybe this eases your task sufficiently that you'll be able to solve the rest yourself:
You don't need to update catalina.bat - instead create a file named setenv.bat in the same directory: It's not included in tomcat, but if it's there, it will be taken into account during startup/shutdown of tomcat.
Speaking about startup/shutdown: The JAVA_OPTS that you set in this file will be used for startup as well as shutdown (there's a java process started when tomcat shall shut down, running for a brief time). If you have massive memory requirements, allocate JMX ports etc, these will apply for both processes, thus may be conflicting. You rather want to set CATALINA_OPTS - this is just used for starting tomcat, not for shutting it down.
So, the typical content for setenv.bat is
SET CATALINA_OPTS="-DyourSettings -DwhateverYouLike"
And, by the way, the same works for setenv.sh on other platforms
Related
I have an application running in a tomcat container in Windows environment.
When I have to update the application, the tomcat windows service is stopped, new ROOT.war file is copied in the webapps folder and tomcat service is restarted.
Sometimes it happens that the ROOT.war extraction fails and the extracted ROOT folder has only few subfolder and few files. Obviously the following application startup fails.
To solve this problem I have to stop tomcat, delete ROOT folder and run in again to let tomcat re-extract the ROOT.war again from the beginning.
I cannot understand why sometimes it happens and sometimes no. However, it makes impossibile to me to create an automatic update. It is too risky.
Do you have any idea why it can happen?
Resources are not released. So, when you try to update the existing war file, tomcat is not able to delete the older files before deployment/redeployment.
To resolve this issue, ensure that:
The application is not open/running on web browser.
You're not stuck in debug mode when you click on update.
All processes/requests are completed before redeployment.
All files/streams are closed within the code.
When all else fails, you may want to stop the application. Then update. There are ways to stop applications on tomcat using command line, batch files, etc. You can then automate the process.
If you want a more reliable way to do this, you may use jrebel or a free version of the same. There are other ways to update code. Basically, standalone tomcat is not worth anything more than a development server.
Remark: if you are updating the application while Tomcat is running you need to either:
use Tomcat Manager to deploy it,
call tryAddServiced (before Tomcat 9.0 addServiced/isServiced) before any modification to the webapps directory and removeServiced afterwards. This can be done through JMX on the bean Catalina:type=Deployer,host=<your_host_name>,
replace the WAR file (almost) atomically: e.g. deleting the old one and moving (renaming) the new one from another location on the same filesystem should work.
which prevents Tomcat from immediately deploying the application until the copy operation is finished.
To prevent the OS from locking the files in the webapps/ROOT folder you have two options:
Use antiResourceLocking="true" as already suggested by Svetlin, which basically forces Tomcat to copy webapps/ROOT to a uniquely named temporary directory before deployment (the copy will be locked, webapps/ROOT will not),
Use parallel deployment by naming your WAR files: ROOT##001.war, ROOT##002.war, etc. This is basically an explicit version of the antiResourceLocking feature with the additional advantage of letting clients transition fluently between the old and new app version.
I have a task to automaticly extend heap memory for our tomcat application. I know it isn't possible by JDK features, and I'm looking for any dirty(or not) hack to make that kinda feature. The main reason of that demand is minimal configuration of tomcat before start demo version of our application. In other word no user of our application will have any access to configuration of JVM/tomcat.
Application required ~1024M of heap memory, default value for tomcat8 is 256M, which isn't appropriate for our goals.
At this moment I have two possible solutions:
An a .sh/.bat script which will configure tomcat. pros - it will do the work, cons - it's another point of configuration demo stand(copying of a script)
An wrapper for our application, which goes in the same war file and configure tomcat if required. pros - it will do the work, and no new configuration point(Just install tomcat and copy the war file),
Is there another way to do that in more... common and simple way?
EDIT The main goal is to make installation of our application in following steps:
Install tomcat
Copy war file
Start tomcat
no any additional configuration, just copy war and start tomcat
That is commonly solved by wrapping the installation and configuration of tomcat in an installation script. Pros: the end user just download the installer and runs it; cons: the installation script must be tailored for the final environment (one for Windows, one for Linux) and can be hard to write. A sometimes simpler way is to provide a zip containing a readme.txt file and a install.bat (or install.sh)
An alternate way if the configuration is really complex is to directly configure a VM (VMDK is a de facto standard), and let the users install the virtualizer they prefere.
In the past 10 years or so, I had the opportunity to deploy web applications into a tomcat countless times. I also wrote several scripts trying to do that automatically, but never
managed to completely automate it.
Here is the issue. I am trying to deploy a new war, with the same name as an existing war in the webapps of my tomcat.
Option 1: The naive approach - just copy the war and wait for it to update the exploded directory. This sometimes work. Many times - the exploded directory is not updated in a reasonable time.
Option 2: The through approach - stop the tomcat, delete all the wars and temporary files. copy the war and start the tomcat. This usually involves stopping the tomcat, waiting for a while - and then checking to see if the process is still alive and killing it.
Option 3: The manual approach - This might be surprising, but I found it to work many of the times - copy the war, wait for the exploded directory to be updated, and once it does -
restart the tomcat. if it doesn't - you can try to delete the temporary work files, and that sometimes help.
I also tried many options - with different order and subset of the actions - restart, stop, delete war, delete exploded, delete localhost context, delete localhost work directory, copy war, sleep, compare dates, ask the tomcat politely to reload, etc. Nothing seemed to just work.
It might be something that I am doing wrong, but I've heard the same experience from numerous people, so I'm here to get some advice - what say you? What is the best way to deploy a new war to a tomcat?
Thanks!
you can easily automate this in a shell script with curl
on tomcat 6:
curl --upload-file deployme.war "http://tomcat:s3cret#localhost:8088/manager/deploy?path=/deployme&update=true"
on tomcat 7
curl -T "deployme.war" "http://tomcat:s3cret#localhost:8080/manager/text/deploy?path=/deployme&update=true"
or via almost any porgramming language. I posted a java based solution here
I tend to go for Option 2. If there is a project I am working on in the ide especially with a debugger attached, I find things eventually start getting messed up. Might be chasing a red herring for an hour before I discover clearing everything away makes the problem go away. Then it is nice to have a script on the side that I can occasionally launch to clear everything up:
shutdown force with a 60s timeout
clear out the log, temp, work directories
clear out the webapp folder
copy in the new war file from the build location
explode the new war file
if necessary, run an awk script to customize machine specific values in the properties files (hence the previous explode)
startup with the CATALINA_PID environment variable set (to enable the shutdown force)
Normally things shutdown nicely. If not, then there is usually a background thread that was started up but missing a shutdown hook (say a memecached client) and needs to be hunted down. Normally, just dropping in the new war seems to work to. But if in a dev environment, a script for doing the full blown restart is nice.
Cargo - http://cargo.codehaus.org/ - can be used to remotely deploy WAR files to a number of web containers, Tomcat included.
See http://cargo.codehaus.org/Quick+start for examples in Java. Ant and Maven support is also available.
I upload the WAR to my home directory, cd to /usr/local/tomcat, then run the following commands:
bin/shutdown.sh
rm webapps/ROOT.war
rm -rf webapps/ROOT
cp ~/ROOT.war webapps
bin/startup.sh
Easy enough to automate, but I've been too lazy (or not lazy enough) to do that thus far.
I just use the Tomcat management tool to stop the process, remove it, and install the new WAR. Easy peasy.
See the section on "Deploying using the Client Deployer Package"
It's basically a ready made ant script to perform common tomcat deployment operations.
http://tomcat.apache.org/tomcat-7.0-doc/deployer-howto.html#Deploying_on_a_running_Tomcat_server
I use Eclipse Indigo (EE) to build applications in Java framework Vaadin,
using Tomcat 7.0 server. After changes in code I wont see result in a browser,
so I need to click option "Clean Tomcat Work Directory.." and wait until
Tomcat stop and start a server.
Otherwise, when I refresh app page, I don't see any changes.
Even when I restart server (and when eclipse automatically restart it when I save changes), without cleaning tomcat directory.
Option "Automatically publish when resources change" is enabled.
Is any faster way to do that? or can I automate that process?
Additionally to the answer of Kowser, it is possible do hot code changes when running tomcat in debug mode.
Otherwise you could investigate in JRebel
In your "Modules" tab of your Tomcat, you hace to clic on 'Edit' and uncheck the 'Auto reloading enables' option.
With that, several changes won't need a restart (as long as you start your server in debug mode).
If you setup your project to use ant for building and deploying, you can simply add Ant builder to your project Builders to run your ant build and deploy targets every time after you have saved a file. Then provided that tomcat is configured to support auto-deploy, this should achieve what you want, with two caveats:
If your project takes more than a few seconds to build, building after every save is not practical.
You may run out of memory for the tomcat instance if the same app is deployed to it repeatedly for a number of times. This can happen if tomcat is somehow unable to recover all the memory from undeployed resources.
It might be possible. But your setup is a bit different from what I use. I am just using tomcat+eclipse to do Servlet development using Velocity and Torque.
The following works for me where changes are visible in the browser as soon as I save in eclipse.
I assume that you have a project directory such as
apache-tomcat-7.0.11/webapps/$YOU_PROJECT/WEB-INF/classes/
Create a symbolic link with ln -s from your eclipse project directory and to the classes directory in WEB-INF.
Then configure eclipse to write all .class files to this directory. (Done by right clicking on the project in Eclipse and choosing Properties and then Java build path.
In your $tomcat/conf/context.xml config file first tag should be:
<Context allowLinking="true" reloadable="true">
Also add the following as a child to if it is not already there.
<WatchedResource>WEB-INF/web.xml</WatchedResource>
That is what I have done, but I am not sure it works with your EE tools.
ps: This solution assumes that you are using linux/unix. I don't know if it works with windows. The major problem is that eclipse can't write class files outside the project directory (Which is why that symlink is required).
btw: Tomcat may(Depending on class loader, used .jar files and other complicated details) leak a lot of memory when automatic reload is enabled so you may want to increase the allowed memory(Mostly permgen) to prevent out of memmory exceptions from tomcat.
I know this has been asked and answered very long ago. But use this info if it is helpful to anyone of you. I use Eclipse Kepler and configured Tomcat 7 server inside eclipse. I don't have to do any other configuration but to just uncheck Update context paths check box. That is all. Leave other setting as default.
In this way, changes to the resources files (xhtml pages, css files etc.) as well as the java source code files show up in the browser. Only for class files the web application would be redeployed (no server restart auto as well as manual required).
Location of Update context paths: Double click on the tomcat server under Server tab. Under Publishing tab you would find this Update context paths check box.
Absolutely no other change needs to be done for the auto publishing. This works both in normal and debug mode of tomcat.
Screen shot from my eclipse below:
No, there is no other way.
You will notice immediate changes only while updating a JSP/HTML/etc.... Classes will not be loaded/refreshed automatically. It will be contradictory to change a loaded/instantiated class when server is live, isn't it? At least it should not be possible.
It's better to perform Unit Test while developing something. It can help you to reduce the amount of annoying server restarts.
I have a Spring app that has a lot of dependencies (18 megabytes of JAR files..) - Now, when I am testing on the remote Tomcat 6.0 server, I'd like to not have to upload that 19 megabytes of dependencies, and just upload the classes. Pretty simple, right?
I can't get the damn thing to work.
I'm using Eclipse 3.4, and if in Java Build Path->Order and Export I remove the export of all of the dependencies, I get a nice small WAR.
So here's what I tried:
I uploaded all of the libs to the server, and stuck them in common/lib in Tomcat. The directory didn't exist, so I created it and modified catalina.properties:
shared.loader=${catalina.home}/common/lib/*.jar
I've tried a bunch of other configs, but none worked. Restart the server, deployed war fails to start. Specifically:
SEVERE: Error configuring application listener of class org.springframework.web.context.ContextLoaderList$java.lang.ClassNotFoundException:org.springframework.web.context.ContextLoaderListener at org.apache.catalina.loader.WebappClassLoader.loadClass(WebappClassLoader.java:1
It's dying trying to load the Log4J listener, which it can't find in its classpath. The spring lib that listener is in is in common/lib.
Also - when I deploy the full 18 megabyte war, it works just fine. Everything inits and the app starts. Of course it works fine locally as well.
Oh - and I've replaced the hardcoded logging JARs with the ones out of the extras folder to allow Log4j to work.
Any help here? I have no idea why this isn't working.
"I have a Spring app that has a lot of dependencies (18 megabytes of JAR files..) - Now, when I am testing on the remote Tomcat 6.0 server, I'd like to not have to upload that 19 megabytes of dependencies, and just upload the classes. Pretty simple, right?"
I don't understand this - 19MB is not a lot. You'd be much better off just packaging a WAR and be done with it.
I recommend that you do your testing locally on your own identical Tomcat instance, get it all working, and then deploy the WAR to the remote Tomcat instance.
UPDATE: One issue I have with putting those JARs in Tomcat's /lib directory is that now every app that you deploy to that instance sees those JARs - change them for one, all are affected. If you put the JARs in each individual WEB-INF/lib, you can modify each application without affecting others. The cost is duplicate JARs and disk space, which is cheap.
Another problem if you have to migrate from devl->test->prod, now every environment has to have the identical JARs deployed in order for your app to work. Miss one and you're broken. Your app depends on having those dependencies available. If they aren't on the server you're out of luck. Keep control in your own hands and package the JARs in the WAR file.
You need to be careful externalizing the dependencies like that in a web server environment. Depending on the server there can be unexpected class-loading issues even when it seems to start up fine.
I agree with duffymo... 19MB is not really all that big... is there some reasoning behind wanting to do this? I wouldn't recommend it.
find the webapp folder
upload the files direct into the folder
for example
/path-to-tomcat/webapp/myapp/
keep the /path-to-tomcat/webapp/myapp/WEB-INF/lib folder and upload the changes to ur /path-to-tomcat/webapp/myapp/classes folder
then use tomcat manager to restart the app
I second the suggestion of sending updates directly to ${CATALINA_HOME}/webapps/<your-app> on the target server. WARs are for production deployment, but if you have a slow connection and a large WAR that's no fun.
You'll want your web app to restart after the update, of course. Tomcat in development mode will monitor a few files for changes; by default WEB-INF/web.xml is one of them, so update that along with whatever else you're updating and you should get an app restart soon. In a pinch, you can use the Manager web app to kick the app awake.
For more control and convenience, you'd eventually do well to use the Tomcat ant tasks (found near the Tomcat distribution, not included with ant!) to restart the server, and perhaps to deploy your changes as well. Takes some fiddling but this is well worth it as you'll want to re-use it for each project you do.
Is WEB-INF/lib empty?
Where is log4j.jar?
Where is spring.jar?
This looks like classloader visibility problem.
Listen to duffymo and cjstehno.
Adding jars to tomcat's is a sure recipe for disaster.
Keep your jars in your webapps directory.
It is strange that Tomcat can't find the jar files. Anyway, place all jars in the common folder (${catalina.home}/lib). (This is even worse than using the shared.folder, but it should work for you).
Of course, like others said, you shouldn't do that in your production system. I believe that is OK for a development system though - especially if you need to do extensive testing with the production system anyway.
Another note: you should only do this if you have full control of the server and you are the only one installing applications.
Why would you change the default ${shared.loader} property of tomcat?