1. A system for supporting service level quorum in a data grid cluster, comprising: a plurality of cluster nodes in the data grid cluster, wherein the data grid cluster supports performing at least one service action; and a quorum policy defined in a cache configuration file associated with the data grid cluster, wherein the quorum policy specifies a minimum number of service members that are required for performing the at least one service action, and wherein the data grid cluster use the quorum policy to determine whether the at least one service action is allowed to be performed based on how many cluster nodes in the data grid cluster are qualified as service members.