This article describes running multiple server instances from one installation instance of Geronimo, where the server instances share as much of the base Geronimo artifacts and file system space as possible. These are the geronimo directories, all sub-directories of <geronimo_home> by default:
- bin
- lib
- schema
- var
- repository
- deploy (hot deployment)
<geronimo_home> is the directory where you installed Geronimo. bin, lib and schema are read-only, and thus may be shared between instances. The disk space taken up by a typical vanilla freshly installed Geronimo instance is equally split between var and repository at almost 50 MB each, with the rest being noise. Most of var is 40 MB of ActiveMQ journal files.This motivates the idea of a second repository, in particular, one for each server instance.
In addition to a simple read/write partition of capabilities, security may well come into play as we access permissions on a set of directories. Each server instance should be able to read or write only its var directory, for instance.
Multiple Server Instances
A server instance is easy to create in Geronimo:
- Set the
org.apache.geronimo.server.name
system property to the instance name before you start the server.- Use the syntax
-Dorg.apache.geronimo.server.name=foo
to name your instancefoo
. - There are two ways to do this:
- Add this to your
GERONIMO_OPTS
environment variable, or - Pass it on the java command-line invocation of the server.
- Add this to your
- The server's var directory will then be in
<geronimo_home>/foo
. org.apache.geronimo.server.name
may be any pathname relative to (descending from) <geronimo_home>. For example,servers/bar
would put the server's var directory in<geronimo_home>/servers/bar
.- The
org.apache.geronimo.server.dir
system property may also be used, and it overridesorg.apache.geronimo.server.name
. - Use
org.apache.geronimo.server.name
to specify an absolute path, which need not be relative to <geronimo_home>. For example,/ag20/servers/bar
would put the server's var directory at/ag20/servers/bar
. Otherwise, the two system properties behave the same.
- Use the syntax
mkdir foo
- Copy var to foo.
- Start the server.
Multiple Repositories
First, we consider the case single server instance case, and just add a second repository. Say we want to leave Geronimo in its repository, but add a second repository to deploy our applications. Adding a second repository is pretty easy.
- Create a plan (say repo2.xml) for your repository module.
repo2.xml
<module xmlns="http://geronimo.apache.org/xml/ns/deployment-1.2"> <environment> <moduleId> <groupId>org.example.configs</groupId> <artifactId>myrepo</artifactId> <version>2.0-SNAPSHOT</version> <type>car</type> </moduleId> <dependencies> <dependency> <groupId>org.apache.geronimo.configs</groupId> <artifactId>j2ee-system</artifactId> <version>2.0-SNAPSHOT</version> <type>car</type> </dependency> </dependencies> <hidden-classes/> <non-overridable-classes/> </environment> <\!--Repository--> <gbean name="Repo2" class="org.apache.geronimo.system.repository.Maven2Repository"> <attribute name="root">repo2/</attribute> <reference name="ServerInfo"> <name>ServerInfo</name> </reference> </gbean> <\!--Configuration Store service--> <gbean name="Local2" class="org.apache.geronimo.system.configuration.RepositoryConfigurationStore"> <reference name="Repository"> <name>Repo2</name> </reference> </gbean> </module>
- Create the repository's root directory.
mkdir <geronimo_home>/repo2
- The directory is specified by the root attribute of the Maven2Repository GBean,
repo2/
in the above example. It is a path relative to the base directory <geronimo_home>. - A resolveToServer attribute is being added to allow this path to be relative to baseServer, which is useful with multiple server instances.
- The directory is specified by the root attribute of the Maven2Repository GBean,
- Deploy the repository module by deploying
repo2.xml
.
Using the new repository
Using the new repository is a little tricky, and is only supported from the command line currently.The essence is to use the --targets
option of the deploy
command to target your module to deploy in your new repository. First, use the deployer list-targets command to see the repositories. The target names are long and cumbersome:
java deployer.jar list-targets
Available Targets:
org.example.configs/myrepo/2.0-SNAPSHOT/car?ServiceModule=org.example.configs/myrepo/2.0-SNAPSHOT/car,j2eeType=ConfigurationStore,name=Local2
org.apache.geronimo.configs/j2ee-system/2.0-SNAPSHOT/car?ServiceModule=org.apache.geronimo.configs/j2ee-system/2.0-SNAPSHOT/car,j2eeType=ConfigurationStore,name=Local
The use of environment variables is recommended for command-line use. For example, set REPO2= org.example.configs/myrepo/2.0-SNAPSHOT/car?ServiceModule=org.example.configs/myrepo/2.0-SNAPSHOT/car,j2eeType=ConfigurationStore,name=Local2
.
To deploy to the new repository, use: deploy --targets %REPO2% sample.war
deploy list-modules
also gives those long target names on each module. However, deploy list-modules %REPO2%
gives the accustomed short output.
The syntax to undeploy from a repo is: java deployer.jar undeploy "%REPO2%|geronimo/jsp-examples/1.1.1/war"
.
Note the | character separates the repository name from the module name. The " quotes are used around the entire parameter to escape this special character from command shell interpretation.
If no --targets
are given on the deploy command, the module is deployed to all repositories. This certainly seems undesirable. If you only want to put the module in one repository, be sure to use the --targets
option!
Multiple Server Instances, each with its own repository(ies)
In the case of multiple server instances, a separate path may be given for the Maven2Repository root attribute for each server. This might be done with config.xml
overrides for each server instance. A better solution is to add a resolveToServer
attribute to this GBean, so that the root
attribute may be set to repository
, and it will thus be unique for each server instance with no changes required for each instance. Each server instance would then have a repository located at <geronimo_home>/<instance_name>/repository
.
What's lacking is console support for multiple repositories, and support for hot deployment and plugins.
An interesting wrinkle here is in what repository is the new repository deployed? It's clear that the second repository (say repo2.xml
above) will be deployed in the first repository. Thus, making this first repository read-only will not work for dynamically adding repositories. Perhaps a second repository is added to contain these server-unique repositories. The second repository must be shared and read-write, so it does not fit nicely in the use case.