I need to write a folder observer that will run in JBoss. The idea is that as soon as a file will appear in a folder we should handle the file and move it somewhere.
I wrote a simple Java class that will use the Java 7 NIO and it observe the folder. Once a file exists appears in the folder I move it to another folder and process it. Currently what I have done is as soon as the file appears I move it and create a new thread to process it.
Since this suppose to run in JBoss I understand now that creating threads in JBoss is not the way to do that and I should use message queues.
Therefore I am about to change the class and call the queue and pass it an object of the file location and expect the JBoss to handle it.
My question is basically am I doing it right? is this the right way to do that in JBoss? Any process that I want to be done in a multi tasking way should be done with message queues?
Thanks in advance,
Sharon
You shouldn't create un-managed threads in a container. JBoss AS 7 / EAP 6 has the facility to let you define your own thread pools and permit the application container to manage these threads. If you want to use threads to do this, you should use a container managed thread pool. Otherwise, a message passing based implementation would work.
I am not fully sure why this application needs to run in a container/JBoss. Setting that aside, one option is to utilize the message oriented model using JMS queues/topics instead of dealing with files.
The other option is to create a JEE6 timer service that will execute your code to move files at a certain interval. So in this scenario JBoss will manage your threads using the ejb thread pool.
Related
We know that during Tomcat startup, it will deploy the .war files of its web applications. My question is after the deployment I need to run a command to modify a file inside WEB-INF/ of the web application which is generated after deployment, and I need to let Tomcat do this automatically for me, is this possible to achieve ? Something like post_run command after deployment.
I found that CustomEventHookListener can probably do this How to run script on Tomcat startup?, but this involves in making a new Java class, and I'm not allowed to do so. I have to figure out way to modify the existing Tomcat configs like server.xml or tomcat.conf in TOMCAT_HOME/conf to do so.
The main issue about not using a Event Hook Listener is that there's no reliable way to tell if the application is ready or not, as Catalina implements it's own lifecycle for each of their components (as seen in https://tomcat.apache.org/tomcat-8.5-doc/api/org/apache/catalina/Lifecycle.html).
Your best shot is to use tail or some external program infer the component's state, but AFAIK there's no way to implement listeners directly in the configuration files.
I am using JBoss Developer studio 10.1.0.GA.
I have a fuse integration project. In my JMX Navigator there are so many unused maven[id] formed. How can they be removed/deleted?
Please refer the image.
Wow, how did that happen? I guess you ran a Camel context locally several times? Did you stop the process in DevStudio console view? That should usually make those processes disappear. In your case there might be several running processes in the console view so stop and close one by one.
Alternatively you could terminate them manually either via the Task Manager (Windows) or by invoking "kill " (Linux).
I would really love to hear what you did to get into that state.
I am currently debugging a web application which uses a drools ruleset inside an EJB to process business rules. It's deployed inside a JBoss server. I've configured eclipse to run the server so I could use Debug on Server functionality of eclipse.
When I reach the class that fires the drools ruleset, the server loses focus and returns after all the rules are fired. Is there a way where I could trace what rules are being fired? Right now, what I do is put logs inside the *.drl files so I know where the application is inside the rules engine.
you can get the generated java source code of any rule when you add a file with name drools.packagebuilder.conf to your %USERHOME% directory.
The file must contain the following instruction:
drools.dump.dir = d:/myDroolsJavaSourceCode
The directory d:/myDroolsJavaSourceCode - Directory (or any other given name) must exist otherwise the Drools Packagebuild will stop execution.
Then you can add this directory to your Eclipse Environment as new project (probably you have to remove the flag 'Default Location' to choose the 'myDroolJavaSourceCode').
Then you can open the file in Eclipse and set break points in the editor.
May be you must attach the directory also during debugging execution twice.
Best regards!
Christof
As far as I know you can't debug drl file. What we did was to encapsulate the logic of when and then in a method, so that you can at least debug that.
Maddy
What I did is I downloaded the sources for drools-engine and compiled the drl files to their java sources. When you run the app, you'll have an option to attach sources when the break point reaches the engine. It's still hard to trace the rules that are fired (multiple rules from different drls can be fired) but it's better than just sysout logging.
Documentation says if you have a context file here:
$CATALINA_HOME/conf/Catalina/localhost/myapp.xml
it will NOT be replaced by a context file here:
mywebapp.war/META-INF/context.xml
It is written here: http://tomcat.apache.org/tomcat-6.0-doc/config/context.html
Only if a context file does not exist for the application in the $CATALINA_BASE/conf/[enginename]/[hostname]/, in an individual file at /META-INF/context.xml inside the application files.
But everytime I re-deploy the war it replaces this myapp.xml with the /META-INF/context.xml!
Why does it do it and how can I avoid it?
Thanx
Undeploy part of redeploy deletes app and the associated context.xml.
If you use maven tomcat plugin you can avoid deleting context.xml if you deploy your app with command like this:
mvn tomcat:deploy-only -Dmaven.tomcat.update=true
More info here: https://tomcat.apache.org/maven-plugin-2.0-beta-1/tomcat7-maven-plugin/deploy-only-mojo.html
You can use deploy-only with parameter mode to deploy the context.xml too.
The short answer:
Just make the TOMCATHOME/conf/Catalina/localhost dir read-only, and keep reading for more details:
For quick deployment mode (Eclipse dynamic web project, direct Tomcat
connection, etc.) on a local/non-shared Tomcat server you can just define your JDBC datasource (or any
other 'web resource') using the META-INF/context.xml file inside the
WAR file. Easy and fast in your local environment, but not suitable for staging, QA, or
production.
For build deployment mode (usually for staging, QA, or prod), JDBC
datasources and other 'web resources' details are defined by the
QA/production team, not the development team anymore. Therefore, they
must be specified in the Tomcat server, not inside the WAR file
anymore. In this case, specify them in the file
TOMCATHOME/conf/Catalina/localhost/CONTEXT.xml (change Catalina
by the engine, and localhost by the host, and CONTEXT by your context accordingly). However,
Tomcat will delete this file on each deployment. To prevent this
deletion, just make this dir read-only; in Linux you can type:
chmod a-w TOMCATHOME/conf/Catalina/localhost
Voila! Your welcome.
The long answer
For historical reasons Tomcat allows you to define web resources (JDBC datasources, and others) in four
different places (read four different files) in a very specific order of precedence, if you happen to define the same resource multiple times. The ones named in the
short answer above are the more suitable nowadays for each purpose, though you could still
use the others (nah... you probably don't want to). I'm not going to
discuss the other ones here unless someone asks for it.
On tomcat7, also woth autoDeploy=false the file will be deleted on undeploy. This is documented and not a bug (althought it avoids good automated deployments with server-side fixed configuration).
I found a workaround which solved the problem for me:
create a META-INF/context.xml file in your webapp that contains
on the Server create a second context "/config-context" in server.xml and put all your server-side configuration parameters there
on the application use context.getContext("/config-context").getInitParameter(...) to access the configuration there.
This allows a per-host configuration that is independent of the deployed war.
It should also be possible to add per-context configurations by adding contexts like "/config-context-MYPATH". In your app you can use the context path oth the app to calculate the context path of the config app.
According to the documentation (http://tomcat.apache.org/tomcat-8.0-doc/config/automatic-deployment.html#Deleted_files) upon redeploy tomcat detects the deletion (undeploy) of your application. So it will start a cleanup process deleting the directory and xml also. This is independent of auto deployment - so it will happen upon redeployment through manager and modification of war also. There are 3 exceptions:
global resources are never deleted
external resources are never deleted
if the WAR or DIR has been modified then the XML file is only deleted
if copyXML is true and deployXML is true
I don't know why, but copyXML="false" deployXML="false" won't help.
Secondly: Making the directory read only just makes tomcat throwing an exception and won't start.
You can try merging your $CATALINA_BASE/conf/Catalina/localhost/myapp-1.xml, $CATALINA_BASE/conf/Catalina/localhost/myapp-2.xml, etc files into $CATALINA_BASE/conf/context.xml (that works only if you make sure your application won't deploy its own context configuration, like myapp-1.xml)
If someone could tell what is that "external resources" that would generally solve the problem.
The general issue as described by the title is covered by Re-deploy from war without deleting context which is still an open issue at this time.
There is an acknowledged distinction between re-deploy which does not delete the context, and deploy after un-deploy where the un-deploy deletes the context. The documentation was out of date, and the manager GUI still does not support re-deploy.
Redeployment means two parts: undeployment and deployment.
Undeployment removes the conf/Catalina/yourhost/yourapp.xml because the
<Host name="localhost" appBase="webapps" unpackWARs="true"
autoDeploy="true"> <!-- means autoUndeploy too!!! -->
</Host>
Change the autoDeploy="false" and Tomcat has no order anymore to remove the conf/Catalina/yourhost/yourapp.xml.
There is an feature that allowes us to make those steps (undeploy/deploy) as one single step (redeploy) that do not remove the context.xml. This feature is available via the manager-text-interface, but the option is not available using the manager-html-interface. You might have to wait until the bug in tomcat is fixed. You can use the method described in this answer as an workaround.
I need a windows shell script which will redeploy my .ear file. I wrote one:
net stop "JBAS50SVC"
copy /y O:\TEMP\app.ear C:\jboss-4.2.3.GA\server\default\deploy\app.ear
net start "JBAS50SVC"
But the problem is that when I try to stop the JBoss service it does not fully unload itself (my suggestion), so when I start it there's no app deployed in JBoss.
You mentioned that JBoss becomes very slow when you use autoDeploy and keep the server running for a month or more. That's likely to be because your permanent generation memory is filling up over time. See this related question.
I think you'd be best served by using the autoDeploy feature as other suggest, and restarting the entire server periodically to clear out PermGen. There's several ways to track PermGen utilization; I add the following to JAVA_OPTS in run.conf:
-XX:+PrintGCTimeStamps -XX:+PrintHeapAtGC -XX:+PrintTenuringDistribution -Xloggc:$LOGDIR/gc.log
Typically to redeploy an application that is self-contained in an ear in jboss just requires replacing the ear. If there is more to the application (such as classes that have to go in the jboss lib directory) then it may require a restart.
In terms of how to restart it, it depends what you are using to start jboss as a service. Some service starters do not actually control the jvm after they start it, so restarting the service just starts a second instance. You can shutdown jboss with the shutdown script in the JBOSS_HOME/bin directory (shutdown.bat) and then deploy and restart the service. Be sure to pause when you do this, as the shutdown command will issue the shutdown request, the server may still be running.
You can just COPY/RENAME the EAR file to deploy directory. JBoss will automatically take care of re-deployment for you.
As mentioned earlier jboss automatically deploys everything you copy into the deploy directory by default.
If not, check if you are working on a vhost that doesnt autodeploy ear files.
<Host name="vhost2" autoDeploy="false" .... />
other than that, I feel like this is a totally different error due to the fact that jboss takes care of deployment for you. Please check the log files for startup errors of your application.
You might want to check the JBoss community wiki on this, there are undoubtedly easier and more reliable methods than a batch file.
Stopping the server should not undeploy the application - that wouldn't make much sense.