Dynamic resource allocation for distributed cluster-storage network

摘要

An apparatus, method and computer program in a distributed cluster storage network comprises storage control nodes to write data to storage on request from a host; a forwarding layer at a first node to forward data to a second node; a buffer controller at each node to allocate buffers for data to be written; and a communication link between the buffer controller and the forwarding layer at each node to communicate a constrained or unconstrained status indicator of the buffer resource to the forwarding layer. A mode selector selects a constrained mode of operation requiring allocation of buffer resource at the second node and communication of the allocation before the first node can allocate buffers and forward data, or an unconstrained mode of operation granting use of a predetermined resource credit provided by the second to the first node and permitting forwarding of a write request with data.

主权项

1. A method of operating a distributed cluster storage network having a host computer system and a storage subsystem, comprising the steps of:
receiving at a first of said plurality of storage control nodes a request to write data to storage from said host computer system; forwarding said data by a forwarding layer at said first of a plurality of storage control nodes to a second of said plurality of storage control nodes; allocating buffer resource for data to be written to said storage by a buffer control component at each of said plurality of storage control nodes; communicating a constrained and unconstrained status indicator of said buffer resource to said forwarding layer, the status indicator communicating an indication of when a particular set of input/output (I/O) operations are being processed expeditiously and when the particular set of I/O operations are under delay; and responsive to receiving said constrained status indicator at said forwarding layer, selecting a constrained mode of operation of a write, said constrained mode of operation requiring allocation of buffer resource at said second storage control node and communication of said allocation before said first storage control node becomes operable to allocate buffer resource for said data and to forward said data.