DATAREDIS-1151 - change clean method keys command to scan

[lihuagang03]

clean method use keys command to get all keys which is blocked, may cause other commands timeout or block.
As the complexity of DEL is O(N), if the number of keys is huge, DEL command could timeout as well.
Using DEL command is very risky in a production environment, right?

Use scan command as default BatchStrategy in RedisCacheWriter, for without locking behavior or with locking behavior.
We use this strategy in the production environment.
Use RedisCacheWriter#clean to asynchronously scan matches online batch scan to delete cached data for spring-data-redis

• https://jira.spring.io/browse/DATAREDIS-1151
• DATAREDIS-1151 - change clean method keys command to scan #532
• Revise RedisCache and documentation #2051

Here are my own thoughts:
Why do so many users raise issues and report that they encounter timeouts and blocks in use?
I'm wondering how we can improve the ease of use of good products?

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[lihuagang03]

Hi, bro.
Can you help to check this? thx! @mp911de

[mp911de]

We cannot do that. Jedis Cluster doesn't support cross-cluster SCAN by reusing a given cursor so we would break functionality for Redis Cluster users.

[lihuagang03]

We cannot do that. Jedis Cluster doesn't support cross-cluster SCAN by reusing a given cursor so we would break functionality for Redis Cluster users.

Okay, thanks for explaining the specific reasons.

[lihuagang03]

We cannot do that. Jedis Cluster doesn't support cross-cluster SCAN by reusing a given cursor so we would break functionality for Redis Cluster users.

The KEYS batch strategy is fully supported using any driver and Redis operation mode (Standalone, Clustered). SCAN is fully supported when using the Lettuce driver. Jedis supports SCAN only in non-clustered modes.

Spring Data Redis /
Redis /
Redis Cache