Method and apparatus for metadata caching

A storage processor, comprising:

• a physical memory hardware;
• and
• at least one processor that is operatively coupled to the physical memory hardware, the at least one processor being configured to perform the operations of:
• receiving a read request;
• classifying the read request as either a random read request or a sequential read request;
• when the read request is classified as a random read request, storing a given track that includes first metadata associated with the read request in a local cache;
• when the read request is classified as a sequential read request, storing a page that includes the first metadata in a global memory of a storage system, the page including a plurality of tracks, the plurality of tracks including the given track;
• and
• retrieving the first metadata from the local cache or the global memory, and using the first metadata to complete the read request,
• wherein the local cache is implemented by using the physical memory hardware, and
• wherein the global memory includes a plurality of global memory portions that are part of a same address space, each global memory portion being implemented by using physical memory hardware that is part of a different one of a plurality of storage processors in the storage system.

A non-transitory computer-readable medium storing one or more process-executable instructions, which when executed by at least one processor of a of a given node cause the given node to perform the operations of:

• receiving a read request;
• classifying the read request as either a random read request or a sequential read request;
• when the read request is classified as a random read request, storing a given track that includes first metadata associated with the read request in a local cache of the given node;
• when the read request is classified as a sequential read request, storing a page that includes the first metadata in a global memory of a storage system of which the given node is part, the page including a plurality of tracks, the plurality of tracks including the given track;
• and
• retrieving the first metadata from the local cache or the global memory of the storage system, and using the first metadata to complete the read request,
• wherein the local cache of the given node is implemented by using a physical memory hardware of the given node, and
• wherein the global memory includes a plurality of global memory portions that are part of a same address space, each global memory portion being implemented by using physical memory hardware that is part of a different one of a plurality of nodes in the storage system, the plurality of nodes including the given node.