All 7 Streams questions
More in Streams
What is a Redis Stream, and how does it differ from a regular Redis list when used as a messaging system? How do you add a new entry to a Redis Stream, and how do you read entries back from it? What is a consumer group in Redis Streams, and how does it enable multiple workers to process the same stream cooperatively? How do you acknowledge that a message read from a consumer group has been successfully processed? How would you handle a message that was delivered to a consumer but never acknowledged, perhaps because that consumer crashed while processing it? How would you design a robust event sourcing system using Redis Streams as the primary event log?
Advertisement
Redis › Streams

How do you limit the size of a Redis Stream to prevent it from growing indefinitely and consuming unlimited memory?

Intermediate

Answer

You use the MAXLEN option when adding entries with XADD, either specifying an exact maximum length or using the approximate trimming option for better performance, which automatically removes the oldest entries once the stream exceeds the specified length, keeping its memory usage bounded over time.
XADD mystream MAXLEN '~' 10000 '*' field 'value'
Real-world example A high volume logging system caps its stream at approximately ten thousand entries, automatically discarding the oldest log entries as new ones arrive, preventing the stream from consuming unbounded memory over time.

Common follow-ups: What is the difference between exact and approximate trimming for performance reasons?;How do you decide an appropriate maximum length for a specific stream's use case?

Redis Memory Optimization;Data Types
All 7 Streams questions