2017-03-02T02:01:03.458+02:00 INFO [SystemJobManager] SystemJob <336ccc80-fedb-11e6-88d8-0050568617f3> [org.graylog2.indexer.indices.jobs.SetIndexReadOnlyAndCalculateRangeJob] finished in 23913ms.
2017-03-02T03:00:40.395+02:00 ERROR [SystemJobManager] Unhandled error while running SystemJob <45d022a0-fedb-11e6-88d8-0050568617f3> [org.graylog2.indexer.indices.jobs.OptimizeIndexJob] org.elasticsearch.ElasticsearchTimeoutException: Timeout waiting for task.
Wherein lies the problem? Should I increase the number of Elasticsearch servers, set up some Elasticsearch parameter, some Graylog parameter or something else?
This is usually a problem with slow I/O or huge indices. Either way, providing faster storage (e. g. using SSDs) can tremendously speed up the process.
If you know what you’re doing, you can also increase the time out for the optimization process or disable index optimization altogether.