Since i’ve had some issues with graylog (messages not being processed) i’ve tried to upgrade graylog using the steps describes in the documentation (http://docs.graylog.org/en/2.5/pages/configuration/graylog_ctl.html#upgrade-graylog).
After the reboot step the webinterface took a long time to ‘reboot’ (about 10 minutes). When it was rebooting neither the search was responding and the system/index gave an immediate error
Fetching global index stats failed: cannot GET http://10.63.1.217:9000/api/system/indices/index_sets/stats (500).
After digging in the log of the server component i saw repeated error message:
Could not connect to 10.63.1.217:9200 which is the elasticsearch component.
Using netstat -l i dont see any process listening on 9200 or 9300 (the default ports used by elasticsearch).
Trying to start elasticsearch in
/opt/graylog/elasticsearch gives me the following error:
Could not find any executable java binary. Please install java in your PATH or set JAVA_HOME.
The colleague who originally installed graylog and maintained it was unable to transfer knowledge/documenation before he left.