Persistent metafile used to cache slot header metadata for improved read performance of objects within an object store

A computing device comprising:

• a memory comprising machine executable code;
• and
• a processor coupled to the memory, the processor configured to execute the machine executable code to cause the processor to:
• determine that data hosted within a performance tier is to be tiered out to a capacity tier of an object store;
• create an object according to a unified object format, wherein the data is stored within slots of the object;
• attach slot header metadata to the object, wherein the slot header metadata comprises two sections of metadata including a first metadata portion comprising a compression group number of a slot within which a block of the data is stored and a compression group logical index in the compression group number at which the slot is located, and a second metadata portion comprising offset and length location information for the data residing in the object;
• store the object into the capacity tier of the object store;
• cache the slot header metadata of the object within a persistent metafile stored within the performance tier, wherein an entry within the persistent metafile for the object maps the slot header metadata of the object to an object identifier of the object, wherein the entry is populated with the compression group number of the slot, the compression group logical index in the compression group, the offset and length location information, and a sequence number of the object;
• utilize the object identifier to identify the object in the object store for accessing a current sequence number specified by the slot header metadata within the object and to identify the entry, within the persistent metafile, for the object for accessing the sequence number specified by the entry;
• compare the sequence number in the entry of the persistent metafile stored within the performance tier with the current sequence number accessed from the object tiered out to the capacity tier of the object store;
• and
• in response to the sequence number in the entry not matching the current sequence number accessed from the object, overwrite the persistent metafile with current slot header metadata read from the object.

A non-transitory machine readable medium comprising instructions for performing a method, which when executed by a machine, causes the machine to:

• determine that data hosted within a performance tier is to be tiered out to a capacity tier of an object store;
• create an object according to a unified object format, wherein the data is stored within slots of the object;
• attach slot header metadata to the object, wherein the slot header metadata comprises two sections of metadata including a first metadata portion comprising a compression group number of a slot within which a block of the data is stored and a compression group logical index in the compression group number at which the slot is located, and a second metadata portion comprising offset and length location information for the data residing in the object;
• store the object into the capacity tier of the object store;
• cache the slot header metadata of the object within a persistent metafile stored within the performance tier, wherein an entry within the persistent metafile for the object maps the slot header metadata of the object to an object identifier of the object, wherein the entry is populated with the compression group number of the slot, the compression group logical index in the compression group, the offset and length location information, and a sequence number of the object;
• utilize the object identifier to identify the object in the object store for accessing a current sequence number specified by the slot header metadata within the object and to identify the entry, within the persistent metafile, for the object for accessing the sequence number specified by the entry;
• compare the sequence number in the entry of the persistent metafile stored within the performance tier with the current sequence number accessed from the object tiered out to the capacity tier of the object store;
• and
• in response to the sequence number in the entry not matching the current sequence number accessed from the object, overwrite the persistent metafile with current slot header metadata read from the object.