Problem: Elasticsearch won't restart
After trying to start Elasticsearch, using
sudo service elasticsearch start, it confirmed that it had started elasticsearch, but when I ran
sudo service elasticsearch statusall I got in response was:
* elasticsearch is not running
Nothing more than that, which was goddammed annoying because I was busy trying to do real work (Reddit).
I found evidence of the cause in /var/log/elasticsearch/elasticsearch.log:
So it was a plugin. But what plugin?
I ran these commands to try and reinstall the licenses:
cd /usr/share/elasticsearch/bin sudo ./plugin remove license sudo ./plugin install license
After running that, I got a better error message:
ERROR: Plugin [watcher] is incompatible with Elasticsearch [2.4.6]. Was designed for version [2.4.4]
So it was the watcher plugin causing problems. Fixing it was easy enough though:
sudo ./plugin install watcher sudo ./plugin install license
That's all it took. I restarted elasticsearch and I was on my way.