Automatic pipeline reload keeps Logstash responsive to configuration changes without waiting for a full service restart, which is useful when iterating on filters and outputs during troubleshooting. A working reload loop reduces ingestion pauses and makes small pipeline edits less disruptive.

When config.reload.automatic is enabled, Logstash periodically checks the pipeline configuration files referenced by path.config (often /etc/logstash/conf.d/*.conf in packaged installs) and rebuilds the affected pipeline when it detects a change. The polling cadence is controlled by config.reload.interval, expressed as a time value such as 3s.

Reloading tears down and recreates the pipeline, which can briefly interrupt inputs and outputs and may cause backpressure while the new pipeline initializes. Syntax errors or missing plugins prevent the updated pipeline from loading, so validating changes before applying them avoids noisy reload attempts. Changes to logstash.yml settings or installed plugin versions still require a full Logstash service restart.

Steps to enable Logstash pipeline reloads:

  1. Enable automatic reload in /etc/logstash/logstash.yml. 
    config.reload.automatic: true
config.reload.interval: 3s
  2. Test the pipeline configuration for syntax errors. 
    $ sudo /usr/share/logstash/bin/logstash --path.settings /etc/logstash --path.data /tmp/logstash-configtest --config.test_and_exit
Using bundled JDK: /usr/share/logstash/jdk
##### snipped #####
Configuration OK
[2026-01-07T04:57:07,733][INFO ][logstash.runner          ] Using config.test_and_exit mode. Config Validation Result: OK. Exiting Logstash

    Using a temporary path.data avoids locking the service data directory during the test.

    Related: How to test a Logstash pipeline configuration

  3. Restart the Logstash service to apply reload settings. 
    $ sudo systemctl restart logstash

    Related: How to manage the Logstash service with systemctl in Linux

  4. Verify reload settings in the monitoring API. 
    $ curl -s http://localhost:9600/_node?pretty
{
  "host" : "host",
  "version" : "8.19.9",
  "http_address" : "127.0.0.1:9600",
  "id" : "3723b694-8264-4225-a32b-a201e0fcb5dc",
  "name" : "host",
  "ephemeral_id" : "41fcc033-dbb7-46e4-9bc0-89979fc3ba5c",
  "snapshot" : false,
  "status" : "green",
  "pipeline" : {
    "workers" : 10,
    "batch_size" : 125,
    "batch_delay" : 50
  },
  "pipelines" : {
    "main" : {
      "ephemeral_id" : "1a56f9cd-4b2a-47e2-bc48-b8a87844b98f",
      "hash" : "72bcdf31c2a48ef99d2c15dfd15ca568a7691b4ab80b56cad8554692de41f757",
      "workers" : 10,
      "batch_size" : 125,
      "batch_delay" : 50,
      "config_reload_automatic" : true,
      "config_reload_interval" : 3000000000,
      "dead_letter_queue_enabled" : false
    }
  }
}

    If the request fails, check the http.host and http.port settings in /etc/logstash/logstash.yml.