One embodiment involves communicatively connecting a master node and a plurality of slave nodes in a cluster without shared storage where each node has a separate repository. Each node in the cluster without shared storage can be configured to exclusively update its repository. The method may include receiving a lock request from a first slave node in the cluster without shared storage. The lock request may be associated with an update request received by the first slave node. The lock request can indicate that the first slave node requires exclusive write access to a data item in the repository of the first slave node. The method includes sending a response to the first slave node granting the lock request based at least in part on data in the repository of the master node. The response may authorize the first slave node to append data to the data item in the repository of the first slave node.