A distributed lock manager (DLM) may be implemented in a distributed computing system that provides virtualized computing resources and/or virtual computing services to clients. Locks may be created and managed by the DLM in response to requests from clients to do so. The components of the DLM may communicate with each other over a network other than one over which client application components communicate with each other or access the shared resources protected by the locks. For example, DLM components may communicate over a control plane network of a cloud computing environment and application components may communicate over a data plane network of the cloud computing environment. The DLM may expose an API to clients, allowing them to make local calls to a DLM component on the same node to perform various lock management operations. The meanings of the lock values may be established by their use in client applications.