Creating Tomcat6 Windows Services
Tomcat March 12th, 2009
Running the default Windows Tomcat installer a Tomcat server named Tomcat6 will be created on the Windows machine.
In the case the tomcat zipped installation file has been used, or if during the installation wizard the option for creating a Windows service hasn’t been checked, or finally, if it is required to have multiple Tomcat services running on the server, the Tomcat features to create new services should be used.
Obviously it’s required to have Java installed, in this case, it’s used the JDK.
The following batch script will install a tomcat service named YourTomcat related to a CATALINA_BASE located in c:\YourDir\YourTomcat.
set JAVA_HOME="c:\Program Files\Java\jdk1.6.0_12\" set TOMCAT_HOME="c:\Program Files\Apache Software Foundation\Tomcat 6.0" set CATALINA_BASE="c:\YourDir\YourTomcat" call service.bat install YourTomcat
JAVA_HOME and TOMCAT_HOME are obviously the places where Tomcat and Java are installed.
What’s the CATALINA_BASE? In few words, from the same Tomcat installation (located in this example in c:\Program Files\Apache Software Foundation\Tomcat 6.0, the TOMCAT_HOME) it’s possible to run more than one server instances. Each Tomcat instance has its own deployed web applications, its own logs, its own configuration and so on.
The CATALINA_BASE needs to have those directories structure:
conf/ logs/ temp/ webapps/ work/
In conf/ it’s possible to copy the content of the conf/ directory of the Tomcat installation, and obviously these files have to be customized, depending on what is required for that specific Tomcat service, i.e. the HTTP, AJP and SHUTDOWN ports, and so on.
In logs/ each tomcat will write its custom Catalina logs or the web application specific logs (i.e. handled by Log4J).
In temp/ Tomcat will obviously place temporary files.
In webapps/ the web applications .war will be placed (and exploded).
in work/ the compiled .jsp will be placed.
Solving Tomcat OutOfMemoryError: Heap space and PermGen space
Tomcat March 12th, 2009
It’s quite common to run In memory problems when running some big Java EE application on a Tomcat server.
Some of the most commmon errors are like the following ones.
This is about a full Heap space:
SEVERE: Servlet.service() for servlet jsp threw exception java.lang.OutOfMemoryError: Java heap space
This other is about the PermGen space that’s a memory area, where compiled classes (and JSPs) are kept, and this error might happen often if the running web application have many .java and .jsp.
MemoryError: PermGen space java.lang.OutOfMemoryError: PermGen space
To increase the memory available to Tomcat, about heap and permgen the correct options are the following ones.
This sets the max heap available to Tomcat at 1Gb of memory:
--JvmMx 1024
This sets the max permgen available to Tomcat at 256Mb of memory:
-XX:MaxPermSize=256m
To change the Tomcat memory settings (when Tomcat is installed on Windows as system service), it’s required to use the command-line tool tomcat6. The next command changes the memory settings for the Tomcat service named Tomcat6
tomcat6 //US//Tomcat6 --JvmMx 1024 ++JvmOptions="-XX:MaxPermSize=256m"
The label //US//Tomcat6 has the meaning of Updating Server parameters for the service named Tomcat6.
Obviously this command should be executed from the directory C:\Program Files\Apache Software Foundation\Tomcat 6.0\bin or from wherever is the bin directory of your Tomcat installation. Or to make things simple, that directoy should be added to your PATH environment variable.
It’s even possible to update memory settings from a GUI frontend, or to view what happened after running the command line tool. Running the following command:
tomcat6w //ES//Tomcat6
a window will open showing all the parameters about the windows service Tomcat6.
It’s possible to see in this image that, after running the previous command, for setting higher memory limits, in the sections Maximum memory pool and at the end of the Java Options the new memory limits are set.
Tomcat Memory Settings on Windows
Setup Tomcat6 on Eclipse
Eclipse, Tomcat January 18th, 2009
Download Eclipse IDE for Java EE Developers from http://www.eclipse.org/downloads/ and tomcat6 from http://tomcat.apache.org/download-60.cgi
Extract both of them where you prefer. I extracted Eclipse in /opt/eclipse and Tomcat in /opt/tomcat6), then run Eclipse.
When you’ll run eclipse it asks you about creating a new workspace (that will be used to store all of your projects), so create a workspace, usually somewhere in your user home directory.
When Eclipse is up and running, choose preferences from the window menu. Choose from the bar on the left: Server, Runtime Environments.
Preferences
Click the button Add, choose Apache Tomcat 6.
New Server Runtime Environment
In the next page, browse on your disk and choose the directory where you previously extracted Tomcat. In my case it’s /opt/tomcat6. Finally click Finish.
New Server Runtime Environment - Server Path
Well, until now we have just told to our workspace where Tomcat “installation” is located on our disk.
But, if we wish to run Java Web Applications within Eclipse, we should setup a Server and eventually assign to it a specific configuration.
Go in the Servers view, right click and choose New, then Server.
Select “Tomcat v6.0 Server” as server type (or probably it will be automatically pre-selected), then, in the Server Runtime environment select box you’ll have to choose “Apache Tomcat v6.0″ (that’s probably the only available option.
New Tomcat Server in Eclipse
Click on Next, Eclipse will prompt you to eventually add (or remove) web projects from this Server, in this case, if your workspace is empty you’ll have not any project to add. So, click Finish.
Add remove Eclipse projects from Tomcat
In the Servers panel, you will see the Tomcat you just added, and in the Project Explorer view, a new Server configuration will magical appear.
So you can edit the configuration file server.xml as you prefer, change AJP or HTTP connector ports and so on, start/stop/debug the server and obviously add and remove projects from it.
Editing Tomcat configuration in Eclipse
It is also possible to add other server “instances”, just right click again in the “Servers” view, and follow the procedure described before.
In this way, you will just a single “Tomcat” binaries location (that you defined in the first step of this tutorial), but you’ll have the chance to add many instances of that server, each of them with its specific configuration (imagine the /conf directory of Tomcat) and its specific web application (imagine the /webapps directory).
Multiple Tomcat Instances in Eclipse
For the more expert ones, it is similar to have more instances on the same tomcat binaries defined on different CATALINA_BASE paths.
I hope this tutorial has been useful, please post any question or comment.