Kept trolling thru logs, and found this in `/var/log/elasticsearch/logstash.log`:

`java.lang.OutOfMemoryError: Java heap space`

Read up on the topic of heap space at: https://www.elastic.co/guide/en/elasticsearch/reference/5.4/heap-size.html
and then modified `/etc/elasticsearch/jvm.options` to increase the heap size thusly (I'm running on a 32GB RAM system):

    -Xms12g
    -Xmx12g

Restarted the elasticsearch service, and after a bit, Kibana started working again :slight_smile:

Let the journey of learning continue...

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