go-shuttle

go-shuttle serves as a wrapper around the azure service-bus go SDK to facilitate the implementation of a pub-sub pattern on Azure using service bus.

NOTE: This library is in early development and should be considered experimental. The api is still moving and can change. We do have breaking changes in v0.*. Use at your own risks.

Conventions & Assumptions

We are assuming that both the publisher and the listener are using go-shuttle

Processor

The processor handles the message pump and feeds your message handler. It allows concurrent message handling and provides a message handler middleware pipeline to compose message handling behavior

Processor Options

MaxConcurrency and ReceiveInterval configures the concurrent message handling for the processor.

StartMaxAttempt and StartRetryDelayStrategy configures the retry behaviour for the processor.

// ProcessorOptions configures the processor
// MaxConcurrency defaults to 1. Not setting MaxConcurrency, or setting it to 0 or a negative value will fallback to the default.
// ReceiveInterval defaults to 2 seconds if not set.
// StartMaxAttempt defaults to 1 if not set (no retries). Not setting StartMaxAttempt, or setting it to non-positive value will fallback to the default.
// StartRetryDelayStrategy defaults to a fixed 5-second delay if not set.
type ProcessorOptions struct {
    MaxConcurrency  int
    ReceiveInterval *time.Duration
    
    StartMaxAttempt         int
    StartRetryDelayStrategy RetryDelayStrategy
}

MultiProcessor

NewMultiProcessor takes in a list of receivers and a message handler. It creates a processor for each receiver and starts them concurrently.

see Processor and MultiProcessor examples

Middlewares:

GoSHuttle provides a few middleware to simplify the implementation of the message handler in the application code

SettlementHandler

Forces the application handler implementation to return a Settlement. This prevents 2 common mistakes:

• Exit the handler without settling the message.
• Settling the message, but not exiting the handler (forgetting to return after calling abandon, for example)

see SettlementHandler example

ManagedSettlingHandler

Allows your handler implementation to just return error. the ManagedSettlingHandler settles the message based on your handler return value.

• nil = CompleteMessage
• error -> Abandon or Deadletter, depending on your configuration of the handler.

see ManagedSettlingHandler

Enable automatic message lock renewal

This middleware will renew the lock on each message every 30 seconds until the message is Completed or Abandoned.

renewInterval := 30 * time.Second
shuttle.NewRenewLockHandler(&shuttle.LockRenewalOptions{Interval: &renewInterval}, handler)

see setup in Processor example

Contributing

This project welcomes contributions and suggestions. Most contributions require you to agree to a Contributor License Agreement (CLA) declaring that you have the right to, and actually do, grant us the rights to use your contribution. For details, visit https://cla.opensource.microsoft.com.

When you submit a pull request, a CLA bot will automatically determine whether you need to provide a CLA and decorate the PR appropriately (e.g., status check, comment). Simply follow the instructions provided by the bot. You will only need to do this once across all repos using our CLA.

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.

Trademarks

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