Finalizing Cluster Configuration

The steps below improve the reliability and manageability of your Seq cluster.

Set the Target Replica Count

In Settings > General, set the cluster "Target replica count" setting to the number of Seq nodes in the cluster:

This serves two purposes:

A system notification will be sent if the data age across the target number of replicas exceeds the target duration (60 seconds by default).
Rolling cluster upgrades use this value (via the /health/cluster endpoint, and seq cluster health CLI command) to determine that the cluster is healthy before and after upgrading each node.

Configure System Notifications

In Settings > Apps, install and configure a plug-in Seq app that will be the target for Seq's internal system notifications.

In Settings > General, at the bottom of the screen, choose that app instance in the "Target app instance" setting:

Create a Recovery Key

Administration tasks such as recovering from broken authentication settings (e.g. expired OIDC client secrets) are usually possible without downtime if a Recovery Key is used. Create one now and store it somewhere safe.

Other Recommendations and Best Practices

Some further suggestions are made here to improve your experience with clustered Seq:

Actively monitor Seq node resources, including memory and CPU utilization, I/O bandwidth consumption, and free vs. used storage. Storage monitoring is very highly-recommended, as storage exhaustion is a source of unplanned downtime.
Implement external node (/health) and cluster (/health/cluster) health checks with an uptime monitor. Investigate any anomalies by correlating timeouts or failures with diagnostics in the cluster diagnostic instance.
Ensure node and database clocks are synchronized with a reliable time source.
Configure backups (Windows, Docker) to a network storage location accessible by all nodes.
The default minimum free disk space reserved by Seq is 4 GB. If you're running a large cluster, setting this in Settings > General to a much higher value (50-100 GB) will improve node robustness.

Finish Configuring your Seq Instance

Clustered Seq is just like regular Seq: it's time now to set up authentication using the provider of your choice, add users, provision API keys for apps, and set up plug-in apps for alerts.