Shutting Down Logstash
editShutting Down Logstash
editTo shut down Logstash, use one of the following commands:
-
On systemd, use:
systemctl stop logstash
-
On upstart, use:
initctl stop logstash
-
On sysv, use:
/etc/init.d/logstash stop
-
If you have the PID, use:
kill -TERM {logstash_pid}
What Happens During a Controlled Shutdown?
editWhen you attempt to shut down a running Logstash instance, Logstash performs several steps before it can safely shut down. It must:
- Stop all input, filter and output plugins
- Process all in-flight events
- Terminate the Logstash process
The following conditions affect the shutdown process:
- An input plugin receiving data at a slow pace.
-
A slow filter, like a Ruby filter executing
sleep(10000)
or an Elasticsearch filter that is executing a very heavy query. - A disconnected output plugin that is waiting to reconnect to flush in-flight events.
These situations make the duration and success of the shutdown process unpredictable.
Logstash has a stall detection mechanism that analyzes the behavior of the pipeline and plugins during shutdown. This mechanism produces periodic information about the count of inflight events in internal queues and a list of busy worker threads.
To enable Logstash to forcibly terminate in the case of a stalled shutdown, use the --pipeline.unsafe_shutdown
flag when
you start Logstash.
Unsafe shutdowns, force-kills of the Logstash process, or crashes of the Logstash process for any other reason may result in data loss (unless you’ve enabled Logstash to use persistent queues). Shut down Logstash safely whenever possible.
Stall Detection Example
editIn this example, slow filter execution prevents the pipeline from performing a clean shutdown. Because Logstash is
started with the --pipeline.unsafe_shutdown
flag, the shutdown results in the loss of 20 events.
bin/logstash -e 'input { generator { } } filter { ruby { code => "sleep 10000" } } output { stdout { codec => dots } }' -w 1 --pipeline.unsafe_shutdown Pipeline main started ^CSIGINT received. Shutting down the agent. {:level=>:warn} stopping pipeline {:id=>"main", :level=>:warn} Received shutdown signal, but pipeline is still waiting for in-flight events to be processed. Sending another ^C will force quit Logstash, but this may cause data loss. {:level=>:warn} {"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", "current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn} The shutdown process appears to be stalled due to busy or blocked plugins. Check the logs for more information. {:level=>:error} {"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", "current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn} {"inflight_count"=>125, "stalling_thread_info"=>{["LogStash::Filters::Ruby", {"code"=>"sleep 10000"}]=>[{"thread_id"=>19, "name"=>"[main]>worker0", "current_call"=>"(ruby filter code):1:in `sleep'"}]}} {:level=>:warn} Forcefully quitting logstash.. {:level=>:fatal}
When --pipeline.unsafe_shutdown
isn’t enabled, Logstash continues to run and produce these reports periodically.