Adjusting optimistic writes in a dispersed storage network

A computing device of a dispersed storage network (DSN), wherein the computing device comprises:

• an interface;
• memory;
• and
• a processing module operably coupled to the interface and the memory, wherein the processing module is operable to:
• execute a plurality of three-phase write operations for writing one or more plurality of sets of encoded data slices to a set of storage units of the DSN, wherein a data object is dispersed storage error encoded to produce a plurality of sets of encoded data slices of the one or more plurality of sets of encoded data slices, wherein a phase of a three-phase write operation of the plurality of three-phase write operations includes a set of write requests regarding a set of encoded data slices of the plurality of sets of encoded data slices, and wherein a write threshold number of favorable responses is required from the set of storage units to complete the a phase of the three-phase write operation and to begin a subsequent phase of the three-phase write operation or a first phase of another three-phase write operation of the plurality of three-phase write operations;
• during execution of the three-phase write operation of the plurality of three-phase write operations:
• determine a write speed of a storage unit of the set of storage units, in processing a write request of the set of write requests, is outside a write speed range;
• determine whether the write speed of the storage unit being outside the write speed range is decreasing performance of the execution of the plurality of three-phase write operations;
• and
• when the write speed is decreasing the performance:
• adjust for one or more subsequent phases of the plurality of three-phase write operations, the execution of one or more subsequent write requests for the storage unit, wherein the adjusting causes write speeds for the set of storage units in executing the one or more subsequent phases to be within the write speed range.