Skip to content

Listeners & Endpoints

The Listeners view shows all message endpoints across your monitored services — both inbound listeners (where messages are received) and outbound senders (where messages are published).

Endpoint Grid

Each endpoint appears as a row with:

ColumnDescription
URIThe endpoint address (e.g., rabbitmq://my-queue, sqlserver://inbox)
ServiceWhich monitored service owns this endpoint
TypeListener / Sender / Durable
StatusAccepting / Stopped / TooBusy / Latched
TransportRabbitMQ / InMemory / SqlServer / Kafka / etc.
Circuit BreakerNone / Active / Paused
Back PressureNone / Triggered

Status Values

StatusMeaning
AcceptingEndpoint is running and processing messages normally
StoppedEndpoint has been paused by an operator
TooBusyBack pressure is throttling this endpoint
LatchedCircuit breaker has tripped — endpoint is paused due to repeated failures

Endpoint Detail

Click an endpoint to open the detail panel:

Configuration

  • Address — full endpoint URI
  • Mode — how messages are received (Sequential, Parallel, Durable)
  • Buffering limitsMaximumMessagesToReceive, MaximumMessageWaitInQueue, BatchSize
  • Circuit breaker settings — failure rate threshold, sampling period, pause duration, reset success threshold

Circuit Breaker

When a circuit breaker is configured, the detail panel shows:

  • Status — Closed (normal) / Open (tripped) / Half-Open (testing)
  • Current failure rate — percentage of recent messages that failed
  • Failures in window — count of failures within the sampling period
  • Tripped at — timestamp when the breaker opened
  • Estimated reset — when the breaker will attempt to close

A tripped circuit breaker pauses the listener to give the downstream system time to recover. Wolverine will periodically test recovery by allowing a small number of messages through (Half-Open state).

Back Pressure

When back pressure is active:

  • Status — Active / None
  • Queue depth — current number of buffered messages
  • Limit — the configured MaximumMessagesToReceive threshold
  • Triggered at — when back pressure was activated

Endpoint Controls

Pause / Restart

Pause Listener — immediately stop processing messages on this endpoint. Messages remain in the queue and will be processed when the listener is restarted.

Restart Listener — resume processing on a paused endpoint.

Pause All / Restart All — apply the operation to all endpoints in the service. Useful for planned maintenance.

Edit Buffering Limits

Opens a form to adjust:

  • Max messages to receive — how many messages to buffer in memory
  • Max wait time — how long messages can wait in the buffer before being rejected
  • Batch size — how many messages to pull per receive operation

Changes take effect immediately without restarting the service.

Edit Circuit Breaker

Opens a form to adjust:

  • Failure rate threshold — what percentage of failures (0–100%) triggers the breaker
  • Sampling period — the time window over which failures are counted
  • Pause duration — how long to pause the endpoint when the breaker trips
  • Success threshold — how many consecutive successes are needed to close the breaker

Changes are applied to the running endpoint without restart.

Transport Type Icons

CritterWatch displays a transport icon alongside each endpoint URI to make it easy to identify at a glance:

  • RabbitMQ (rabbit icon)
  • SQL Server (database icon)
  • In-memory (lightning bolt icon)
  • Kafka (stream icon)
  • Azure Service Bus (cloud icon)

Released under the MIT License.