Graceful shutdown for log_parser and ingestor_* jobs in Logstash 1.6

[mrdavidlaing]

There is some ongoing work for Logstash 1.6 concerning graceful shutdown - elastic/logstash#3451

When upgrading, we should also ensure that we send the TERM signal on shutdown (followed by KILL) to give Logstash the opportunity to shut down gracefully.

See the .deb package for an example - https://github.com/elastic/logstash/blob/master/pkg/logstash.sysv.debian#L119-L142

[mrdavidlaing]

@dpb587 - Currently we shutdown the log_parsers with a call to kill_and_wait; which I assume sends a KILL signal.

However, I note that we appear to have "graceful shutdown` messages in the logs.

{:timestamp=>"2015-07-16T23:50:25.752000+0000", :message=>"SIGTERM received. Shutting down the pipeline.", :level=>:warn}

Is kill_and_wait polite already? (Ie, does it send a TERM and only later a KILL)

[mrdavidlaing]

So.. the default kill is a TERM, so we're already doinging a graceful shutdown - see https://github.com/logsearch/logsearch-boshrelease/blob/develop/jobs/log_parser/templates/helpers/ctl_utils.sh#L73

Nothing to see here. Move along