Extra library of actors for the Ergo Framework 3.0 (and above)

leader

Distributed leader election for coordinating work across a cluster - task schedulers, resource managers, singleton workers. Term-based election with a quorum taken over the peers the actor currently knows.

Discovery is your job: resolve peers however suits your deployment and hand the names to Join. The actor negotiates with them, and membership propagates through the protocol once one side knows the other.

Features:

• Term-based election with automatic failover
• A leader that steps down on its own once it can no longer reach a quorum
• MinClusterSize floor, so a fragment too small to be a cluster does not operate as one
• Consumer-driven membership: Join / Leave, never withdrawn by the library on silence alone
• Optional confirmation of leadership against an authority outside the cluster
• No external dependencies

There is one leader per cluster, but the number of clusters is not fixed, so from outside you can see two leaders at once. Not from a dropped connection - that keeps the peer in the view, so quorum does not shrink and only one side can elect - but from diverged views, which is what a cold start without seed nodes produces. Set MinClusterSize above half the expected node count and two disjoint groups can never both qualify.

Two things you must do, both of which fail quietly if skipped: register the wire types on the node before it carries traffic (leader.NetworkTypes(), leader.ErrorTypes()), and set MinClusterSize deliberately rather than inheriting the default. See Leader for details.

See documentation for details.

health

Kubernetes health probe actor that serves /health/live, /health/ready, and /health/startup endpoints. Actors register named signals with probe type and optional heartbeat timeout. When a signal goes down (missed heartbeat, process termination, or explicit notification), the corresponding probe endpoint returns 503.

Features:

• Kubernetes liveness, readiness, and startup probe endpoints
• Signal registration with bitmask probe selection and heartbeat timeout
• Automatic failure detection on heartbeat timeout or process termination
• Thread-safe HTTP responses via atomic operations
• External mux support for sharing a port with other HTTP handlers
• Package-level helper functions for convenient signal management

See documentation for details.

metrics

Prometheus metrics exporter actor that automatically collects and exposes Ergo node and network telemetry via HTTP endpoint. Provides observability for monitoring cluster health, resource usage, and inter-node communication patterns.

Features:

• Automatic collection of node metrics (uptime, processes, memory, CPU)
• Network metrics per remote node (messages, bytes transferred, connection uptime)
• HTTP endpoint exposing metrics in Prometheus format
• Extensible - embed metrics.Actor to add custom application metrics
• Configurable collection interval
• External mux support for sharing a port with other HTTP handlers
• Observer UI integration for real-time inspection

See documentation for details.