​Server

How to configure options for the Kestra Server.

HTTP Basic Authentication

You can protect your Kestra installation with HTTP Basic Authentication.

kestra:
  server:
    basic-auth:
      enabled: true
      username: admin
      password: kestra

HTTP Basic Authentication is disabled by default - you can enable it in your Kestra configuration, as shown above. If you need more fine-grained control over user and access management, the Enterprise Edition provides additional authentication mechanisms, including features such as SSO and RBAC. For more details, see the Authentication page.

Delete configuration files

kestra.configurations.delete-files-on-start:

This setting allows to delete all configuration files after the server startup. It prevents the ability to read configuration files (that may contain your secrets) from a Bash task for example. The server will keep these values in memory, and they won't be accessible from tasks.

Server Liveness & Heartbeats

Kestra's servers use a heartbeat mechanism to periodically send their current state to the Kestra backend, indicating their liveness. That mechanism is crucial for the timely detection of server failures and for ensuring seamless continuity in workflow executions.

Here are the configuration parameters for all server types starting from Kestra 0.16.0.

Note that although it's recommended to deploy the same configuration for all Kestra servers, it's perfectly safe to set different values for those parameters depending on the server type.

kestra.server.liveness.enabled

Enable the liveness probe for the server. This property controls whether a server can be detected as DISCONNECTED or not. Must always be true for production environment.

kestra.server.liveness.interval

Frequency at which an Executor will check the liveness of connected servers.

kestra.server.liveness.timeout

The time an Executor will wait for a state update from a server before considering it as DISCONNECTED.

kestra.server.liveness.initialDelay

The initial delay after which an Executor will start monitoring the liveliness of a server joining the cluster.

kestra.server.liveness.heartbeatInterval

The interval at which a server will send a heartbeat indicating its current state. Must be strictly inferior to kestra.server.liveness.timeout.

Recommended configuration for production

Here is the default and recommended configuration for production ():

For JDBC deployment-mode (OSS):

kestra:
  server:
    liveness:
      enabled: true
      interval: 5s
      timeout: 45s
      initialDelay: 45s
      heartbeatInterval: 3s

For Kafka deployment-mode (Enterprise Edition):

kestra:
  server:
    liveness:
      timeout: 1m
      initialDelay: 1m

For Kestra versions prior to 0.16.0

Prior to Kestra 0.16.0, the liveness mechanism was only supported by Workers (JDBC deployment mode). A Worker was either UP or DEAD. Executors was responsible to detect unhealthy workers as follows:

• If the last received Heartbeat for a Worker is older than heartbeat-missed * frequency, then the Worker is marked as unhealthy.
• If the last received Heartbeat for a Worker is older than heartbeat-missed * frequency * 2, then the Worker is deleted from the server metadata.

kestra.heartbeat.frequency

The interval at which a Worker will send a heartbeat indicating its current state.

kestra.heartbeat.heartbeat-missed

The number of missed heartbeats before Executors will consider a Worker as DEAD.

Worker Task Restart Strategy

Starting with Kestra 0.16.0, you can configure the strategy to be used by Executors when a Worker is detected as unhealthy regarding uncompleted tasks (JDBC deployment mode).

kestra.server.workerTaskRestartStrategy

The strategy to be used for restarting uncompleted tasks in the event of a worker failure.

Supported strategies are:

• NEVER:

Tasks will never be restarted in the event of a worker failure (i.e., tasks are run at most once).

• IMMEDIATELY:

Tasks will be restarted immediately in the event of a worker failure, (i.e., as soon as a worker is detected as DISCONNECTED). This strategy can be used to reduce task recovery times at the risk of introducing duplicate executions (i.e., tasks are run at least once).

• AFTER_TERMINATION_GRACE_PERIOD:

Tasks will be restarted on worker failure after the kestra.server.terminationGracePeriod. This strategy should prefer to reduce the risk of task duplication (i.e., tasks are run exactly once in the best effort).

Termination Grace Period

When a Kestra Server receives a SIGTERM signal it will immediately try to stop gracefully.

Starting with Kestra 0.16.0, you can configure the termination grace period for each Kestra Server. The termination grace period defines the allowed period for a server to stop gracefully.

kestra.server.terminationGracePeriod

The expected time for the server to complete all its tasks before shutting down.