2019年12月31日 · In Redis/Valkey Streams, stream is a data type, a data structure on its own right. Messages or entries are stored in memory and stay there until commanded to be deleted. Sync/Async communication (Push/Pull) Pub/Sub is synchronous communication (push protocol). All parties need to be active at the same time to be able to communicate.

2019年12月19日 · Redis Xtrim is to keep a number of records and remove the older ones. suppose I am having 100 records, I want to keep the newest 10 ones. (suppose java/scala API) redis = new Jedis(...) redis.xlen("mystream") // returns 100 // new records arrive stream at here redis.xtrim("mystream", 10)

2020年4月1日 · Since Redis 6.2, XTRIM supports a new trimming strategy: MINID. With this strategy, Redis will evict entries whose ids are lower than the given threshold . So if you use timestamp as entry id, e.g. the default, auto-generated id use Unix timestamp (in milliseconds) as part of the id, you can use this strategy to expire events based on time, i.e ...

I upgraded to spring-data-redis 2.4.6 (I believe it's the newest stable release at the time of this writing) and I still get an exception when creating group of empty stream using opsForStream().createGroup().

2019年2月20日 · I've created a Redis stream: XADD mystream * foo bar And I've associated it with a consumer group: XGROUP CREATE mystream mygroup $ Now I want to delete it, so that Redis acts as though the stream had never existed. How do I delete it? I've tried using XTRIM: XTRIM mystream MAXLEN 0 This successfully puts the length of the stream to zero.

2020年7月27日 · I am trying to listen on a redis stream and process the message as and when they arrive. I am using async command and I expect the message to be pushed instead of being pulled. So I don't think a while loop is required. But the following code seems to not work.

2019年3月6日 · redis.xadd(stream_name, {key: value}) Block to read: redis.xread({stream_name: '$'}, None, 0) stream_name and ID should be a dictionary. $ means the most new message. Moreover, instead of passing a normal ID for the stream mystream I passed the special ID $.

2019年1月9日 · You can avoid using a prefix by using namespacing capability provided by redis. You can assign a 'database' (0-15 by default) for streams names. Say you use database 5 for streams, then scan command in database 5 should return the keys in it only. redis.io/commands/select

2022年3月8日 · The goal would be to keep retrying any message that wasn't acknowledged until it succeeds, to ensure that the stream of events is always processed in exactly the order it was produced. My understanding is if we specify the readOffset as '>' then on every poll it will use '>' and it will never see any messages from the PENDING list.

Redis streams much faster. They stored and operated from memory so this one is as is case. We have some project with Kafka, RabbitMq and NATS. Now we are deep look into Redis stream to trying using it as "pre kafka cache" and in some case as Kafka/NATS alternative. The most critical point right now is replication: