Applicability
When to Use
✓When message processing must be guaranteed
✓When transient failures are expected
✓When failed messages need manual investigation
Overview
How It Works
This pattern uses a message queue (RabbitMQ or Kafka MCP Server) with automatic retry logic and dead letter handling. When a message fails processing, it is retried with exponential backoff. After a configurable number of retries, it moves to a dead letter queue for manual investigation.
In an MCP architecture, the agent consumes messages, processes them using other MCP servers, and acknowledges success or failure. The dead letter queue ensures no messages are silently lost, while the retry mechanism handles transient failures like network timeouts or temporary service unavailability.
Implementation
Code Example
typescript
async function processWithRetry(message, maxRetries = 3) {
for (let attempt = 1; attempt <= maxRetries; attempt++) {
try {
await processMessage(message);
await rabbitmq.ack(message);
return;
} catch (err) {
if (attempt === maxRetries) {
await rabbitmq.publish({ exchange: "dlx", routingKey: "failed", message: { ...message, error: err.message, attempts: attempt } });
await rabbitmq.ack(message);
await slack.sendMessage({ channel: "#alerts", text: `Dead letter: ${message.id} after ${attempt} attempts` });
} else {
await sleep(Math.pow(2, attempt) * 1000);
}
}
}
}Quick Info
Categorymessaging
ComplexityMedium