# Prerequisites To send messages from AxoSyslog to HDFS, complete the following steps. ## Steps: 1. If you want to use the Java-based modules of AxoSyslog (for example, the Elasticsearch, HDFS, or Kafka destinations), you must compile AxoSyslog with Java support. * Download and install the Java Runtime Environment (JRE), 1.7 (or newer). You can use OpenJDK or Oracle JDK, other implementations are not tested. * Install [gradle]() version 2.2.1 or newer. * Set `LD_LIBRARY_PATH` to include the `libjvm.so` file, for example:`LD_LIBRARY_PATH=/usr/lib/jvm/java-7-openjdk-amd64/jre/lib/amd64/server:$LD_LIBRARY_PATH` Note that many platforms have a simplified links for Java libraries. Use the simplified path if available. If you use a startup script to start AxoSyslog set `LD_LIBRARY_PATH` in the script as well. * If you are behind an HTTP proxy, create a `gradle.properties` under the `modules/java-modules/` directory. Set the proxy parameters in the file. For details, see [The Gradle User Guide](). 2. Download the Hadoop Distributed File System (HDFS) libraries (version 2.x) from . 3. Extract the HDFS libraries into a temporary directory, then collect the various `.jar` files into a single directory (for example, `/opt/hadoop/lib/`) where AxoSyslog can access them. You must specify this directory in the AxoSyslog configuration file. The files are located in the various `lib` directories under the `share/` directory of the Hadoop release package. (For example, in Hadoop 2.7, required files are `common/hadoop-common-2.7.0.jar`, `common/libs/*.jar`, `hdfs/hadoop-hdfs-2.7.0.jar`, `hdfs/lib/*`, but this may change between Hadoop releases, so it is easier to copy every `.jar` file into a single directory. Last modified August 28, 2024: [Formatting fixes (c26e237)]()