Elasticsearch.md

Elasticsearch tips

Installation on Debian

Documentation: Install Elasticsearch with Debian Package

wget -qO - https://artifacts.elastic.co/GPG-KEY-elasticsearch | sudo apt-key add -
sudo apt-get install apt-transport-https
echo "deb https://artifacts.elastic.co/packages/5.x/apt stable main" \
    | sudo tee -a /etc/apt/sources.list.d/elastic-5.x.list
sudo apt-get update
sudo apt-get install elasticsearch

Troubleshooting: Java 8 required

When starting:

$ /usr/share/elasticsearch/bin/elasticsearch --help
Exception in thread "main" java.lang.UnsupportedClassVersionError: org/elasticsearch/bootstrap/Elasticsearch :
Unsupported major.minor version 52.0
    at java.lang.ClassLoader.defineClass1(Native Method)
    at java.lang.ClassLoader.defineClass(ClassLoader.java:803)
    ...
    at java.lang.ClassLoader.loadClass(ClassLoader.java:358)
    at sun.launcher.LauncherHelper.checkAndLoadMain(LauncherHelper.java:482)

This is because the default java version on Debian Jessie is Java 7. Elasticsearch need Java 8:

    $ sudo apt-get install openjdk-7-jre
    $ sudo update-alternatives --set java /usr/lib/jvm/java-8-openjdk-amd64/jre/bin/java
    $ java -version
    openjdk version "1.8.0_111"

Running manually

Elasticsearch can be started using systemd (or classic sysv init scripts), but I like to do things manually :)

$ mkdir -p es/conf
$ sudo cat /etc/elasticsearch/log4j2.properties > es/conf/log4j2.properties
$ /usr/share/elasticsearch/bin/elasticsearch  --verbose -p es/pid \
    -Edefault.path.logs=es/logs  -Edefault.path.data=es/data  -Edefault.path.conf=es/conf
$ curl 0:9200
{
  "cluster_name" : "elasticsearch",
  "version" : {
    "number" : "5.0.1",
    ...
  },
  ...
  "tagline" : "You Know, for Search"
}

For some intro to Elasticsearch continue with Guide: Findihg your feet ;)