5.0 KiB
Using the Server
This chapter will familiarise you with how to use the ActiveMQ server.
We'll show where it is, how to start and stop it, and we'll describe the directory layout and what all the files are and what they do.
For the remainder of this chapter when we talk about the ActiveMQ server we mean the ActiveMQ standalone server, in its default configuration with a JMS Service enabled.
Starting and Stopping the standalone server
In the distribution you will find a directory called bin
.
cd
into that directory and you will find a Unix/Linux script called
activemq
and a Windows script called activemq.cmd
.
To start the ActiveMQ instance on Unix/Linux type ./activemq run
To start the ActiveMQ instance on Windows type activemq.cmd run
These scripts are very simple and basically just set-up the classpath and some JVM parameters and bootstrap the server using Airline.
To stop the ActiveMQ instance you will use the same activemq
script.
To run on Unix/Linux type ./activemq stop
To run on Windows type activemq.cmd stop
Please note that ActiveMQ requires a Java 6 or later runtime to run.
By default the config/non-clustered/bootstrap.xml
configuration is
used. The configuration can be changed e.g. by running
./activemq run -- xml:../config/clustered/bootstrap.xml
or another
config of your choosing.
Server JVM settings
The run scripts set some JVM settings for tuning the garbage collection policy and heap size. We recommend using a parallel garbage collection algorithm to smooth out latency and minimise large GC pauses.
By default ActiveMQ runs in a maximum of 1GiB of RAM. To increase the
memory settings change the -Xms
and -Xmx
memory settings as you
would for any Java program.
If you wish to add any more JVM arguments or tune the existing ones, the run scripts are the place to do it.
Pre-configured Options
The distribution contains several standard configuration sets for running:
-
Non clustered stand-alone.
-
Clustered stand-alone
-
Replicated stand-alone
-
Shared-store stand-alone
You can of course create your own configuration and specify any configuration when running the run script.
Library Path
If you're using the Asynchronous IO Journal on Linux,
you need to specify java.library.path
as a property on your Java
options. This is done automatically in the scripts.
If you don't specify java.library.path
at your Java options then the
JVM will use the environment variable LD_LIBRARY_PATH
.
System properties
ActiveMQ can take a system property on the command line for configuring logging.
For more information on configuring logging, please see the section on Logging.
Configuration files
The configuration file used to bootstrap the server (e.g.
bootstrap.xml
by default) references the specific broker configuration
files.
activemq-configuration.xml
. This is the main ActiveMQ configuration file. All the parameters in this file are described in ?. Please see ? for more information on this file.
It is also possible to use system property substitution in all the configuration files. by replacing a value with the name of a system property. Here is an example of this with a connector configuration:
<connector name="netty">tcp://${activemq.remoting.netty.host:localhost}:${activemq.remoting.netty.port:61616}</connector>
Here you can see we have replaced 2 values with system properties
activemq.remoting.netty.host
and activemq.remoting.netty.port
. These
values will be replaced by the value found in the system property if
there is one, if not they default back to localhost or 61616
respectively. It is also possible to not supply a default. i.e.
${activemq.remoting.netty.host}
, however the system property must be
supplied in that case.
Bootstrap File
The stand-alone server is basically a set of POJOs which are instantiated by Airline commands.
The bootstrap file is very simple. Let's take a look at an example:
<broker xmlns="http://activemq.org/schema">
<file:core configuration="${activemq.home}/config/stand-alone/non-clustered/activemq-configuration.xml"></core>
<basic-security/>
</broker>
- core - Instantiates a core server using the configuration file from the
configuration
attribute. This is the main broker POJO necessary to do all the real messaging work. In addition all JMS objects such as: Queues, Topics and ConnectionFactory instances are configured here.
The main configuration file.
The configuration for the ActiveMQ core server is contained in
activemq-configuration.xml
. This is what the FileConfiguration bean
uses to configure the messaging server.
There are many attributes which you can configure ActiveMQ. In most
cases the defaults will do fine, in fact every attribute can be
defaulted which means a file with a single empty configuration
element
is a valid configuration file. The different configuration will be
explained throughout the manual or you can refer to the configuration
reference here.