Add EX, PX, NX, XX options to SET command. [DATAREDIS-316]

[spring-projects-issues]

Christoph Strobl opened DATAREDIS-316 and commented

see: http://redis.io/commands/set

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Affects: 1.3 GA (Dijkstra)

Reference URL: https://twitter.com/tonyghita/status/478684001977520128

Referenced from: pull request #170

2 votes, 5 watchers

[spring-projects-issues]

Simon commented

Just as a hint since this issue is still open and we have to rely on a complex "watch", "setnx" and "expire" construct for creating an expiring lock in an atomic way.

Adding something like the SetParams parameter to the set operation would solve this issue: https://github.com/xetorthio/jedis/blob/50e8d346096a4963eae6622882a78e23ed5ab9ee/src/main/java/redis/clients/jedis/params/set/SetParams.java#L8

Jedis set operation using the SetParams: https://github.com/xetorthio/jedis/blob/master/src/main/java/redis/clients/jedis/commands/JedisCommands.java#L19

[spring-projects-issues]

Simon commented

The references in my previous comment are not released and currently referenced version of Jedis only supports this feature using the

BinaryJedisCluster.set(final byte[] key, final byte[] value, final byte[] nxxx, final byte[] expx, final long time)
``` method. 

We could implement a version using a `SetParams` like params object which only supports the parameters that the current version of `Jedis` supports but we would have a hard time implementing it in `JRedis` because several commands seem to be missing (https://github.com/alphazero/jredis/issues/52) and looking at the current api it seems like there is no support for this operation in an atomic way. The only solution would be to fallback to a custom `WATCH`, `SETNX` and `EXPIRE` multi operation

[spring-projects-issues]

Simon commented

Just found out that there is already an implementation that uses the described pattern to create an expiring lock in redis in the spring-integration project and that this solution is also used by the the spring-cloud-cluster redis implementation. Providing this atomic operation in the spring-data-redis project might therefore also lead to reduction regarding spring ecosystem duplications / dependencies

[spring-projects-issues]

Simon commented

Just saw DATAREDIS-405 which would allow us to implement this only using Jedis. Would be great to get feedback on the situation

[spring-projects-issues]

Christoph Strobl commented

thanks Simon for the heads up - true that issue is overdue - will take care