java - shared connection in hadoop under setup method -

i have initialized redis(jedis) client-connection in setup method in hadoop mr job. when use connection in map job update key,value pairs, can maps running on multiple nodes simultaneously use same connection update redis? or there lock on connection?

i not sure if got question correctly. if in case have initialised redis client in setup phase of mapper each mapper use own connection communicate redis. since mappers run in own jvm don't believe can share connections across them.

and yes,multiple clients can write redis simultaneously.if them writing same key in redis internally handle case never takes cluster level lock.