udpates docs

README.md

@@ -225,4 +225,53 @@ router.HandlerFunc("mobile_app_log_consumer/mobile-application-logs/(1|3|5|7|9|1
 router.HandlerFunc("mobile_app_log_consumer/mobile-application-logs/(2|4|6|8|10|12)", func (ctx, *ziggurat.Event) error {....})
 ```
 
-Based on how the routing path is set by the message consumer implementation, you can define your routing paths.
+Based on how the routing path is set by the message consumer implementation, you can define your routing paths.
+
+### Retries
+Ziggurat-Go includes rabbitmq as the backend for message retries. Message retries are useful when message processing from one message consumer fails and needs to be retried.
+
+The `rabbitMQ.AutoRetry(qc QueueConfig,opts ...Opts)` function creates an instance of the `rabbitmq.ARetry struct`
+
+Required params
+```go
+type QueueConfig struct {
+	QueueKey              string  // A queue key to be used for retries, any arbitrary string would do
+	DelayExpirationInMS   string  // The time in milliseconds after which to reconsume the message for processing
+	RetryCount            int     // The number of times to retry the message
+	ConsumerPrefetchCount int     // The number of messages in batch to be consumed from RabbitMQ 
+	ConsumerCount         int     // Number of concurrent consumer instances
+}
+
+type Queues []QueueConfig
+```
+#### How does queue key work
+A practical example
+Suppose your queue key is called `foo_retries`. The RabbitMQ retry module will automatically create 3 queues namely 
+- `foo_retries_instant_queue`
+- `foo_retries_delay_queue`
+- `foo_retries_dlq`
+It will also create an exchange by the name `foo_retries_exchange`. This exchange is internally used to send messages to the right queue.
+Consumption only happens from the instant queue. The delay queue is where the retried message is sent and once the retries are exhausted they are sent to the dlq.
+
+#### I have a lot of messages in my dead letter queue, how do I replay them
+The RabbitMQ package provides HTTP handlers which clear the messages on the RabbitMQ queues. These handlers can be used with any HTTP server.
+
+Example usage:
+```go
+router := http.NewServeMux()
+ar := rabbitmq.AutoRetry()
+router.Handle("POST /ds_replay", ar.DSReplayHandler(context.Background()))
+router.Handle("POST /ds_view", ar.DSViewHandler(context.Background()))
+http.ListenAndServe("localhost:8080", router)
+```
+Just invoke the API with the following query params
+| Param   | Example   |
+| ------- | --------- |
+| count\* | 100       |
+| queue\* | foo_retry |
+
+> [!NOTE]
+> * indicates a required param
+
+> [!CAUTION]
+> Using a Prefetch of 1 is not beneficial for consumption and can fill up the RabbitMQ queues, use a higher value from 10 to 300.

mw/rabbitmq/queue.go

@@ -27,7 +27,7 @@ func createQueuesAndExchanges(ch *amqp.Channel, queueName string, logger ziggura
 	for _, qt := range queueTypes {
 		args := amqp.Table{}
 		logger.Info("creating queue", map[string]interface{}{"queue": queueName, "type": qt})
-		if qt == "delay" {
+		if qt == QueueTypeDelay {
 			args = amqp.Table{
 				"x-dead-letter-exchange":    fmt.Sprintf("%s_%s", queueName, "exchange"),
 				"x-dead-letter-routing-key": QueueTypeInstant,