[STORM-703] RedisMapState with hash key can cause network overload

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Affects Version/s: 0.10.0
• Fix Version/s: 0.10.0
• Component/s: storm-redis
• Assignee: Dave Katten
• Reporter: Dave Katten
• Created: 11/Mar/15 23:53
• Updated: 29/Sep/15 02:42
• Resolved: 24/Mar/15 14:42

Description

When RedisMapState is constructed to use a hash key (and store values under a hash in redis, rather than as key/value pairs in the top namespace), a multiGet actually requests ALL of the state in that hash, instead of only the keys in the batch.

As the size of the hash grows in redis, this becomes an inordinate amount of traffic, and can cause interfaces to fall over.

• Solution
  Instead of calling jedis.hgetall(hash), call jedis.hmget(hash, stringKeys[]). Also, remove the buildValuesFromMap function, as it is no longer needed.

See PR#462 on github.
https://github.com/apache/storm/pull/462