At-most-once delivery

Q: How deeply does C# Concurrency: Asynchronous and multithreaded programming cover at-most-once delivery?

Defines the guarantee through a crash scenario and contrasts it with at-least-once and usually impossible exactly-once delivery.

As explained in C# Concurrency: Asynchronous and multithreaded programming

At-most-once delivery is a message-delivery guarantee that delivers a message zero or one time and does not intentionally retry it after loss.

At-most-once delivery removes a message from a persistent queue before processing it. A crash afterward can lose the message, but the system will not intentionally process it again. section 8.2.3

Power loss before processing

A worker removes an item, then the computer loses power before processing begins. After restart, the item is absent and is never processed. This avoids duplicates but permits loss. section 8.2.3

Use this guarantee when:

Losing an item is preferable to processing it twice. section 8.2.3
You have assessed persistent-queue behavior alongside at-least-once delivery and poison-message handling. section 8.2.3 section 8.3

How C# Concurrency: Asynchronous and multithreaded programming covers it

Cover of C# Concurrency: Asynchronous and multithreaded programming

liveBook manning.com

Read C# Concurrency: Asynchronous and multithreaded programming on liveBook Get the book at manning.com

Also explained in

liveBook manning.com

Kafka Streams in Action, Second EditionAt-most-once delivery is a processing guarantee that avoids reprocessing by committing before processing completes, at the risk of losing records.
liveBook manning.com

Think Distributed SystemsA message-delivery guarantee in which each sent message is delivered zero or one time.
liveBook manning.com

Apache Kafka in ActionAt-most-once delivery is a message delivery guarantee that permits message loss but prohibits duplicate delivery.
liveBook manning.com

Akka in Action, Second EditionAn at-most-once delivery guarantee means each record is delivered zero or one time, so records may be lost but are not redelivered.

Compare how 5 books explain at-most-once delivery →

Related concepts

at-least-once deliverycontrasts with · At-least-once delivery is a messaging or processing guarantee that each message or record is delivered or processed one or more times, so duplicates may occur.
acks=0configured by · acks=0 is a Kafka producer setting that requires no acknowledgment from the broker and provides no delivery or persistence guarantee.
exactly-once deliverycontrasts with · Exactly-once delivery is a messaging or processing guarantee that each message or input produces its intended effect once, without loss or duplicate effects, despite retries or failures.

This explainer was generated by Manning's knowledge graph from the text of C# Concurrency: Asynchronous and multithreaded programming. The section links point to the parts of the book it draws on.