Implicit locking goes one step ahead and locks cache keys behind the scene as keys are accessed for modification operations.

Consider a transaction running on one of the cache nodes:

   tx.begin() 
   cache.put(K,V)    // acquire cluster wide lock on K 
   cache.put(K2,V2)  // acquire cluster wide lock on K2 
   cache.put(K,V5)   // no-op, we already own cluster wide lock for K 
   tx.commit()       // releases locks

Implicit eager locking locks cache keys across cluster nodes only if it is necessary to do so. In a nutshell, if implicit eager locking is turned on then for each modification Infinispan checks if cache key is locked locally. If it is then a global cluster wide lock has already been obtained, otherwise a cluster wide lock request is sent and lock is acquired.

Implicit eager locking is enabled as follows:

<transaction useEagerLocking="true" />