System and method for multiplexing channels over multiple connections in a storage system cluster

A system configured to multiplex channels over multiple connections between a first and second node, the system comprising:

• a connection layer of each node configured to open a plurality of connections between a pair of nodes in the cluster;
• a session layer of each node configured to create a session between the pair of nodes, each session including a plurality of channels disposed over the connections, each channel enabling one or more messages to be sent over a connection between the nodes, the session layer further configured to multiplex the messages from the channels of the session over any available connection;
• and
• a cluster fabric interface module of each node, the cluster fabric interface module configured to implement a network protocol that enables intra-cluster communication among the nodes;
• wherein the network protocol is a request/response protocol wherein a node (requester) receiving a data access request from a client redirects that request to another node (responder) that services the request and, upon completion, returns a response.

An apparatus configured to multiplex channels over multiple connections, the apparatus comprising:

• means for opening a plurality of connections between a pair of elements;
• means for creating a session between the pair of elements, the session including a plurality of channels disposed over the connections, each channel enabling one or more messages to be sent over a connection between the elements;
• means for multiplexing the messages from the channels over any available connection;
• means for embodying each channel as a request window having a plurality of entries for staging the messages sent over the connection;
• and
• means for, within each session, selecting any request window with an available entry to send a message, thereby obviating the possibility of one long-running or lost request blocking the progress of the session.

A computer readable medium encoded thereon executable program instructions for multiplexing channels over multiple connections, the computer readable medium when executed by a computer cause the computer to perform:

• opening a plurality of connections between a pair of elements;
• creating a session between the pair of elements, the session including a plurality of channels disposed over the connections, each channel enabling one or more messages to be sent over a connection between the elements;
• multiplexing the messages from the channels over any available connection;
• embodying each channel as a request window having a plurality of entries for staging the message sent over the connection;
• and
• within each session, selecting any request window with an available entry to send a message, thereby obviating the possibility of one long-running or lost request blocking the progress of the session.