Amazon SQS | FIFO Queue(First-In-First-Out).

 

Amazon SQS FIFO (First-In-First-Out) queues are designed to ensure exactly-once processing and message order preservation.

Here's twtech clear breakdown of how they work and what makes them different from standard queues:

 Key Features of SQS FIFO Queues

Feature	Description
Order Preservation	Ensures messages are processed in the exact order they are sent (within a message group).
Exactly-Once Processing	Prevents duplicate message delivery using deduplication mechanisms.
Message Groups	Messages with the same MessageGroupId are always processed in order; multiple groups can be processed in parallel.
Limited Throughput	300 transactions per second (TPS) by default (can be increased with batching).
Supports Message Batching	Send or receive up to 10 messages in a single batch to improve throughput.
Deduplication	Ensures no duplicate messages are delivered. Deduplication is based on content or a MessageDeduplicationId.

 Key Configuration Parameters

Parameter	Purpose
Content-Based Deduplication	If enabled, SQS uses a SHA-256 hash of the message body to deduplicate.
MessageGroupId	Required for FIFO queues. Groups related messages for ordered processing.
MessageDeduplicationId	Optional unless content-based deduplication is disabled. Unique ID for deduplication within 5 minutes.

twtech Use Cases.

• Financial transactions – where order matters.
• Inventory management – maintain consistent state.
• Workflow systems – steps that must happen in sequence.

 FIFO vs Standard Queue Comparison

Feature	FIFO Queue	Standard Queue
Ordering	Strict (per message group)	Best-effort (not guaranteed)
Duplicates	Eliminated	Possible
Throughput	Limited (300 TPS/group)	Nearly unlimited
Use Case	Order-sensitive workflows	High-volume, unordered data

 Security & Monitoring

• IAM policies for access control.
• Server-side encryption (SSE) available with AWS KMS.
• CloudWatch metrics for monitoring and troubleshooting.
• Dead Letter Queues (DLQs) to handle message processing failures.

Project: Hands-on

How twtech creates an SQS(simple queue service) and configure for FIFO(First-In-First-Out

Search for the service: SQS

Create a queue and assign a name: twtech.fifo

NB:

The name must end with .fifo for it to be created.

Configuration

Set the maximum message size, visibility to other consumers, and message retention.

Deduplication scope

Specify the scope of deduplication for a FIFO queue.

Encryption

Amazon SQS provides in-transit encryption by default. To add at-rest encryption to your queue, enable server-side encryption.

Access policy

Define who can access your queue.

Choose method.

Create Quequ: twtech.fifo

How twtech send and receive messages from fifo queue.

Configure then send message with Message group ID: twtech-fifo-id-1

 And

Message deduplication ID: twtech-dedu-id-1

Send the message: Hello twtech fifo team 1

Send another message for twtech team 2: Hello twtech fifo team 2

Configure then send message with Message group ID: twtech-fifo-id-2

 And

Message deduplication ID: twtech-dedu-id-2

Send message: Hello twtech fifo team 2

Send another message for twtech team 3: Hello twtech fifo team 3

Configure then send message with Message group ID: twtech-fifo-id-3

 And

Message deduplication ID: twtech-dedu-id-3

Send message: Hello twtech fifo team 3

Send another message for twtech team 3: Hello twtech fifo team 4

Configure then send message with Message group ID: twtech-fifo-id-4

 And

Message deduplication ID: twtech-dedu-id-4

Send message: Hello twtech fifo team 4

How twtech polls for the messages sent:

From:

To:

How twtech accesses all the four messages sent to twtech-teams(1.2,3,4): by clicking on each message ID.

Message to: twtech-team 1

Message to: twtech-team 2

Message to: twtech-team 3

Message to: twtech-team 4

Insight:

The messages have a guarantee of FIFO(firt-in-first-out)

First-come first-served.