Can I run two tomcat instances on the same machine?

Can I run two Tomcat servers with two different ports on the same machine? Will it create any problem? When I run a tomcat it will create the javaw.exe file in the task manager.

Apart from changing Connector port for protocol="HTTP/1.1" described in one of the answers below.

I think it requires to change Server port for 'Shutdown'

<Server port="8005" shutdown="SHUTDOWN">

and also AJP port no.

<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" />

If you want to run multiple tomcat instances in parallel.

Yes !. You can. You need to change your port to have another instance.

To do so follow the steps.

1.) Locate server.xml in {Tomcat installation folder}\ conf \

2.)Find following similar statement

<!-- Define a non-SSL HTTP/1.1 Connector on port 8180 -->
    <Connector port="8080" maxHttpHeaderSize="8192"
               maxThreads="150" minSpareThreads="25" maxSpareThreads="75"
               enableLookups="false" redirectPort="8443" acceptCount="100"
               connectionTimeout="20000" disableUploadTimeout="true" />

3.) About Tomcat’s server.xml file cites it’s runs on port 8080. Change the Connector port=”8080″ port to any other port number.

For example

<Connector port="8181" protocol="HTTP/1.1" 
               connectionTimeout="20000" 
               redirectPort="8443" />

4) Edit and save the server.xml file. Restart Tomcat. Done

Yes, that's absolutely fine. I've done it on numerous occasions. You'll need to check all the ports you're using for Tomcat though. I can't remember whether it still has a special "local control" port, but if so those will need to be different too.

In general we also set CATALINA_HOME property. so startup script first reads catalina_home and than from it figures out rest of the path. If this environment variable is set and if you try to run tomcat from any copy-paste tomcat installation location, you will get tomcat running which is pointed by CATALINA_HOME.

So while running two tomcat from same machine, remove the CATALINA_HOME property. That way it will set the CATALINA_HOME property based on directory from which you are running the startup script.

Adding a few pointers to detailed instructions on how to accomplish that:

1. Step by step Running Multiple Tomcat Instances on One Server.
2. An older version of the above.
3. Explanation of various environment variables & folders that play a role in such setup.

Here is my expperience/process of making two Tomcats (Tom1 and Tom2) running on Windows:

1. Setup Tomcat according to http://www.ntu.edu.sg/home/ehchua/programming/howto/Tomcat_HowTo.html

2. However, Tom1 starts up fine, but not Tom2.

3. So in addition to the above, in server.xml, make/change the following (on Tomcat 6.0.44, JDK 1.6.0_45):

   Line 22: Tom1 shutdown port = 9001
   Line 22: Tom2 shutdown port = 9002

   Line 53: Tom1 service name = "Catalina1"
   Line 53: Tom2 service name = "Catalina2"

   Line 69: Tom1 connector (http) = 9001
   Line 69: Tom2 connector (http) = 9002

   Line 71: Tom1 redirect port = 8443
   Line 71: Tom2 redirect port = 8444

   Line 90: Tom1 connector (ajp) = 8009
   Line 90: Tom1 redirect = 8443
   Line 90: Tom2 connector (ajp) = 8010
   Line 90: Tom2 redirect = 8444

   Line 102: Tom1 engine name = "Catalina1"
   Line 102: Tom2 engine name = "Catalina2"

4. Starting up each server

Voila!

I've faced a similar situation and the answer mentioned here, solves it in much crisp and simple fashion.

> Let's say that you have only one Tomcat folder located in C:\apache-tomcat-7.0.39, and that you wish to run two instances from it. > > Make sure that you have CATALINA_HOME system/user variable set, and > pointing to C:\apache-tomcat-7.0.39 > > Create a folder C:\instance1. Copy conf, webapps and temp folders from > C:\apache-tomcat-7.0.39 and paste them to C:\instance1. You can delete > contents from webapps and temp folders located under instance1, but > don't touch conf contents. Now copy>paste C:\instance1 and rename it > to instance2. That way, both instance1 and instance2 will have the > same content. Go to C:\instance2\conf, edit server.xml and change the > numbers of these ports (I marked those as XXXX): > > > > redirectPort="8443" /> > > > Deploy whatever you want into instance1\webapps and instance2\webapps > Create the following 4 batch files under C:
> > instance1_startup.bat > > @echo off >
> set CATALINA_BASE=C:\instance1 >
> cd "%CATALINA_HOME%\bin" >
> set TITLE=My Tomcat Instance 01 >
> call startup.bat %TITLE% > > instance1_shutdown.bat > > @echo off >
> set CATALINA_BASE=C:\instance1 >
> cd "%CATALINA_HOME%\bin" >
> call shutdown.bat > > instance2_startup.bat > > @echo off >
> set CATALINA_BASE=C:\instance2 >
> cd "%CATALINA_HOME%\bin" >
> set TITLE=My Tomcat Instance 02 >
> call startup.bat %TITLE% > > instance2_shutdown.bat > > @echo off >
> set CATALINA_BASE=C:\instance2 >
> cd "%CATALINA_HOME%\bin" >
> call shutdown.bat > > Run instance1_startup.bat and instance2_startup.bat, hopefully it > should work.

you can run unlimited instances of tomcat on your server/pc, ofcourse you need to define each one with different port.

As already discussed here, you can either omit the CATALINA_HOME environment variable and use the catalina.sh script to manage your container's life cycle or you could define another variable like CATALINA_HOME1 to point to the new tomcat's installation directory and modify it's catalina.sh script to use CATALINA_HOME1 instead of the original CATALINA_HOME reference.

In any case, you could avoid it all together by omitting any environment variable named CATALINA_HOME references and just link to the corresponding tomcat's catalina.sh script.

example:

cd /usr/sbin
ln -s /usr/local/java/apache-tomcat-6.0.37/bin/catalina.sh catalina1
ln -s /usr/share/java/apache-tomcat-6.0.37/bin/catalina.sh catalina2

Then start your tomcats like this (from anywhere):

catalina1 start
catalina2 start

Tom