Synchronous write persistence. The storage solution must guarantee data write to durable and persistent storage when the synchronous write call returns.

Distributed file locking. The storage solution must not assign the locks to two servers simultaneously. Broker Servers must be able to request and obtain an exclusive lock on the shared storage.

Unique write ownership. The Broker Server process that has the file lock must be the only server process that can write to the file. Once the system transfers the lock to another server, the pending write requests queued by the previous owner must fail.

Write order. The storage solution must write data blocks to the shared storage in the same order as they occur in the data buffer.