Method and system for dynamic topology-aware space allocation in a distributed system

A computer system, comprising:

• a processor;
• and
• a memory coupled to the processor and storing instructions which, when executed by the processor, cause the processor to perform a method, the method comprising:
• dividing non-volatile memory of a plurality of storage devices into physical extents which comprise chunks;
• allocating slabs associated with the storage devices,
• wherein a respective slab comprises a plurality of extents from different storage devices and further comprises a plurality of stripes, and
• wherein a respective stripe of the respective slab comprises a chunk from each extent of the respective slab;
• updating, in a first data structure, an entry which indicates:
• a slab number for the respective allocated slab;
• and a storage device identifier and an extent number for each extent in the respective allocated slab;
• responsive to receiving a write request, obtaining a first stripe from a pre-allocated list which includes the allocated slabs;
• searching, based on stripe information associated with the first stripe, the first data structure to obtain a physical location in a storage device to which to issue the write request;
• issuing the write request based on the obtained physical location;
• responsive to determining that a total number of stripes in the allocated slabs is not greater than a predetermined threshold, allocating additional slabs to the allocated slabs;
• updating, in a second data structure, entries corresponding to stripes in the allocated slabs by marking the stripes as set to a pre-allocated state;
• and
• placing the marked stripes in the pre-allocated list.

A non-transitory computer-readable storage medium storing instructions that when executed by a computer cause the computer to perform a method, the method comprising:

• dividing non-volatile memory of a plurality of storage devices into physical extents which comprise chunks;
• allocating slabs associated with the storage devices,
• wherein a respective slab comprises a plurality of extents from different storage devices and further comprises a plurality of stripes, and
• wherein a respective stripe of the respective slab comprises a chunk from each extent of the respective slab;
• updating, in a first data structure, an entry which indicates:
• a slab number for the respective allocated slab;
• and a storage device identifier and an extent number for each extent in the respective allocated slab;
• responsive to receiving a write request, obtaining a first stripe from a pre-allocated list which includes the allocated slabs;
• searching, based on stripe information associated with the first stripe, the first data structure to obtain a physical location in a storage device to which to issue the write request;
• responsive to determining that a total number of stripes in the allocated slabs is not greater than a predetermined threshold, allocating additional slabs to the allocated slabs;
• updating, in a second data structure, entries corresponding to stripes in the allocated slabs by marking the stripes as set to a pre-allocated state;
• and
• placing the marked stripes in the pre-allocated list.