I researched the message limits per queue in Amazon SQS, so I’ll share my findings.
Maximum Message Limits per SQS Queue
For Standard Queues
Maximum 120,000 inflight messages.
A queue can have a maximum of 120,000 inflight messages (received from a queue by a consumer, but not yet deleted from the queue). When this limit is reached, Amazon SQS returns an OverLimit error message. 「キューには最大 120,000 のインフライトメッセージが存在できます (received from a queue by a consumer, but not yet deleted from the queue)。この制限に達した場合、Amazon SQS は OverLimit エラーメッセージを返します。」
For FIFO Queues
Maximum 20,000 inflight messages.
A queue can have a maximum of 20,000 inflight messages (received from a queue by a consumer, but not yet deleted from the queue). When this limit is reached, Amazon SQS does not return an error message. 「キューには最大 20,000 のインフライトメッセージが存在できます (received from a queue by a consumer, but not yet deleted from the queue)。この制限に達した場合、Amazon SQS はエラーメッセージを返しません。」
Background on Why I Wanted to Know SQS Message Limits
In batch processing, I had a requirement to “put nearly 1000 messages for external API requests into a single SQS queue,” and I thought “I need to make sure not to hit the maximum message limit per SQS queue,” which is why I researched this.
That’s all about being curious about the maximum message count per SQS queue from the Gemba.