activemq-artemis/docs/user-manual/en/libaio.md

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Libaio Native Libraries

Apache ActiveMQ distributes a native library, used as a bridge between Apache ActiveMQ and Linux libaio.

libaio is a library, developed as part of the Linux kernel project. With libaio we submit writes to the operating system where they are processed asynchronously. Some time later the OS will call our code back when they have been processed.

We use this in our high performance journal if configured to do so, please see Persistence.

These are the native libraries distributed by Apache ActiveMQ:

  • libActiveMQAIO32.so - x86 32 bits

  • libActiveMQAIO64.so - x86 64 bits

When using libaio, Apache ActiveMQ will always try loading these files as long as they are on the library path.

Compiling the native libraries

In the case that you are using Linux on a platform other than x86_32 or x86_64 (for example Itanium 64 bits or IBM Power) you may need to compile the native library, since we do not distribute binaries for those platforms with the release.

Install requirements

Note

At the moment the native layer is only available on Linux. If you are in a platform other than Linux the native compilation will not work

These are the required linux packages to be installed for the compilation to work:

  • gcc - C Compiler

  • gcc-c++ or g++ - Extension to gcc with support for C++

  • libtool - Tool for link editing native libraries

  • libaio - library to disk asynchronous IO kernel functions

  • libaio-dev - Compilation support for libaio

  • A full JDK installed with the environment variable JAVA_HOME set to its location

To perform this installation on RHEL or Fedora, you can simply type this at a command line:

sudo yum install libtool gcc-c++ gcc libaio libaio-devel make

Or on Debian systems:

sudo apt-get install libtool gcc-g++ gcc libaio libaio-dev make

Note

You could find a slight variation of the package names depending on the version and Linux distribution. (for example gcc-c++ on Fedora versus g++ on Debian systems)

Invoking the compilation

In the source distribution or git clone, in the activemq-native directory, execute the shell script compile-native.sh. This script will invoke the proper maven profile to perform the native build.

someUser@someBox:/checkout-dir/activemq-native$ ./compile-native.sh
[INFO] Scanning for projects...
[INFO]
[INFO] ------------------------------------------------------------------------
[INFO] Building ActiveMQ6 Native POM 6.0.0
[INFO] ------------------------------------------------------------------------
[INFO]
[INFO] --- nar-maven-plugin:3.0.0:nar-validate (default-nar-validate) @ activemq-native ---
[INFO] Using AOL: amd64-Linux-gpp
[INFO]
[INFO] --- maven-enforcer-plugin:1.4:enforce (enforce-java) @ activemq-native ---
...

The produced library will be at ./target/nar/activemq-native-RELEASE-amd64-Linux-gpp-jni/lib/amd64-Linux-gpp/jni/ libactivemq-native-RELEASE.so. Simply move that file over bin with the proper rename library path.

If you want to perform changes on the Apache ActiveMQ libaio code, you could just call make directly at the native-src directory.