Writing an object

Writing an Object to ZSS works more efficiently than PSS. Writes are completed in three phases: lock, persist and finalize.

Lock

Locks the passed slice name and revision in order to provide consistency for concurrent writes of the same slice name and revision. This phase also ensures there is enough available storage space to write the slice and fails before the slice data is sent if the remaining free space on the disk is less than the slice size.

Persist

Slice data is written to disk. The slice is now durable. Data is made visible to client systems or APIs. An attempt to access this object will succeed. The result of persist phase is visible when a write threshold of IBM Cloud® Object Storage Slicestor® devices report success. The persist operation is complete when all available IBM Cloud Object Storage Slicestor devices complete an operation either successfully or with failure.

Finalize

If the object being written is an update of an existing object, the previous revision of the data is removed from the system when it is finalized. The finalize phase starts once slices have been committed to a number of IBM Cloud Object Storage Slicestor® nodes equal to the IDA Write Threshold.