Switching system

• US 20040117438A1
• Filed: 09/03/2003
• Published: 06/17/2004
• Est. Priority Date: 11/02/2000
• Status: Active Grant

• Current Assignee: Oracle America, Inc. (Oracle Corporation)
• Original Assignee: Sun Microsystems (Oracle Corporation)
• Inventors: Considine, John, Hall, Howard, Cochrane, Christopher
• Granted Patent: US 7,313,614 B2
• Time in Patent Office: Days
• US Class Current: 709/203
• CPC Class Codes: G06F 11/2074 Asynchronous techniques
• CPC Class Codes: G06F 11/2087 with a common controller
• CPC Class Codes: G06F 3/0613 in relation to throughput
• CPC Class Codes: G06F 3/0635 by changing the path, e.g. traffic rerouting, path reconfiguration
• CPC Class Codes: G06F 3/067 Distributed or networked storage systems, e.g. storage area networks [SAN], network attached storage [NAS]
• CPC Class Codes: H04L 49/1523 Parallel switch fabric planes
• CPC Class Codes: H04L 49/201 Multicast operation; Broadcast operation
• CPC Class Codes: H04L 49/351 for local area network [LAN], e.g. Ethernet switches
• CPC Class Codes: H04L 49/354 for supporting virtual local area networks [VLAN]
• CPC Class Codes: H04L 49/355 Application aware switches, e.g. for HTTP
• CPC Class Codes: H04L 67/1097 for distributed storage of data in networks, e.g. transport arrangements for network file system [NFS], storage area networks [SAN] or network attached storage [NAS]

Abstract

A system and method for provided a switch system (100) having a first configurable set of processor elements (102) to process storage resource connection requests (104), a second configurable set of processor elements capable of communications with the first configurable set of processor elements (102) to receive, from the first configurable set of processor elements, storage connection requests representative of client requests, and to route the requests to at least one of the storage elements (104), and a configurable switching fabric (106) interconnected between the first and second sets of processor elements (102), for receiving at least a first storage connection request (104) from one of the first set of processor elements (102), determining an appropriate one of the second set of processors for processing the storage connection request (104), automatically configuring the storage connection request in accordance with a protocol utilized by the selected one of the second set of processors, and forwarding the storage connection request to the selected one of the second set of processors for routing to at least one of the storage elements.

Claims

1. In a digital network including at least first and second Client Servers, each of the first and second Client Servers being operable to communicate with (1) respective local clients and (2) a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the digital network being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating read access to data by clients, the method comprising:

providing, for each of the first and second Client Servers, a respective local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing, for each of the first and second Client Servers, a respective local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

receiving a read access request from a client in communication with the first or second Client Server;

in response to receipt of the read access request, checking the local write cache for a data segment match;

if no data segment match is found in the local write cache, checking the local read cache for a data segment match;

if the segment is found in the local cache, transmitting to the remote Data Server a request to determine the validity of the data in the local read cache, thereby to determine whether the data in the local read cache must be updated from the remote Data Server,

if the data in the local read cache is not valid, or if no data segment match is found in the local read cache, transmitting the read access request to the remote Data Server for serving of the requested data; and

once the requested data is transmitted from the remote Data Server,

storing a copy of the requested data in the local read cache.

2. The method of claim 1, further comprising:

assigning a time-stamp to a data segment stored in the local read cache;

assigning a time-stamp to a data segment stored in the remote Data Server;

upon receipt of a request to determine the validity of the data in the local read cache, comparing the time-stamp of the data segment stored in the local read cache with the time-stamp of a comparable data segment stored in the remote Data Server to determine whether the data segment in the local read cache is older than the comparable data segment on the remote data server; and

if the data segment in the local read cache is older than the comparable data segment on the remote data server, designating as invalid the data segment in the local read cache.

3. The method of claim 2, further comprising:

if the data segment in the local read cache is designated invalid, then transmitting the read access request to the remote Data Server for serving of the requested data; and

once the requested data is transmitted from the remote Data Server, storing a copy of the requested data in the local read cache and updating the respective time-stamps.

Multiple Client Servers—

Writes

4. In a digital network including at least first and second Client Servers, each of the first and second Client Servers being operable to communicate with (1) respective local clients and (2) a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the digital network being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating response to write access requests by clients, the method comprising:

providing, for each of the first and second Client Servers, a respective local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing, for each of the first and second Client Servers, a respective local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

receiving a write request from a client in communication with the first or second Client Server;

in response to receipt of the write request, checking the respective local read cache for a data segment match, and if a matching data segment is detected, invalidating the matching data segment;

checking the respective local write cache for a data segment match, and if a matching write segment is detected, invalidating or reusing the matching write segment;

transmitting to the remote Data Server a request to determine whether the write segment is available for writing, and if the segment is unavailable, waiting for the write segment to become available;

generating a new write cache entry representing the write data segments to be written; and

transmitting to the remote Data Server a request to unlock the data segments to be written.

5. The method of claim 4 further comprising:

determining whether data segments are available for writing by the first Client Server by checking whether the data segments are being written or otherwise are locked by the second Client Server during the time the first Client Server requests write access to the same or overlapping data segments.

6. The method of claim 5 wherein the determining further comprises generating a lock request on the requested data segment if the segment is available.

7. In a switching system adapted to interconnect local clients in communication with a Client Server, the Client Server being operable to communicate with a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating read access to data by clients, the method comprising:

providing a local data cache operable to communicate with the Client Server;

storing within the local data cache a copy of data recently read from the remote Data Server;

determining, when a client in communication with the Client Server requests data by means of a read request, whether the requested data is present in the local data cache; and

if the requested data is present in the local data cache, providing the client access to the cached data from the local data cache;

or,

if the requested data is not present in the local data cache, transmitting the read request to the remote Data Server for serving of the requested data by the remote Data Server, and, once the requested data is transmitted to the Client Server, storing a copy of the requested data in the local data cache.

8. In a switching system adapted to interconnect local clients in communication with a Client Server, the Client Server being operable to communicate with a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating response to write access requests by clients, the method comprising:

providing a local data cache operable to communicate with the Client Server;

when data to be written is received from a client, storing the data in the local data cache and transmitting to the client a write operation completion signal upon storage of the data in the local data cache; and

subsequently transmitting the data to be written to the remote Data Server for writing out to the storage devices connected thereto.

11. In a switching system adapted to interconnect local clients in communication with a Client Server, the Client Server being operable to communicate with a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, severs and storage devices, a method of accelerating read access to data by clients, the method comprising:

providing a local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing a local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

storing within the local data cache a copy of data recently read from the remote Data Server;

receiving a read access request from a client in communication with the Client Server;

in response to receipt of the read access request, checking the local write cache for a data segment match;

if no data segment match is found in the local write cache, checking the local read cache for a data segment match;

if no data segment match is found in the local read cache, transmitting the read access request to the remote Data Server for serving of the requested data; and

once the requested data is transmitted from the remote Data Server, storing a copy of the requested data in the local read cache.

12. In a switching system adapted to interconnect local clients in communication with a Client Server, the Client Server being operable to communicate with a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating response to write access requests by clients, the method comprising:

providing a local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing a local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

receiving a write request from a client in communication with the Client Server,

in response to receipt of the write request, checking the local read cache for a matching read segment and, if a matching read segment is detected, invalidating the matching read segment,

checking the local write cache for matching write segments and, if a matching write segment is detected, invalidating or reusing the write segment, and

generating a new local write cache entry representing the write data segment.

13. In a switching system including at least first and second Client Servers, each of the first and second Client Servers being operable to communicate with (1) respective local clients and (2) a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating read access to data by clients, the method comprising:

providing, for each of the first and second Client Servers, a respective local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing, for each of the first and second Client Servers, a respective local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

receiving a read access request from a client in communication with the first or second Client Server;

in response to receipt of the read access request, checking the local write cache for a data segment match;

if no data segment match is found in the local write cache, checking the local read cache for a data segment match;

if the segment is found in the local cache, transmitting to the remote Data Server a request to determine the validity of the data in the local read cache, thereby to determine whether the data in the local read cache must be updated from the remote Data Server,

if the data in the local read cache is not valid, or if no data segment match is found in the local read cache, transmitting the read access request to the remote Data Server for serving of the requested data; and

once the requested data is transmitted from the remote Data Server, storing a copy of the requested data in the local read cache.

9. The method of claim 14 further comprising:

accumulating in the local data cache multiple segments of data to be written; and

subsequently transmitting the multiple segments of data to be written in a batch operation to the remote Data Server.

10. The method of claim 9 wherein the multiple segments of data to be written are transmitted in a semi-contiguous write access to the remote Data Server.

14. The method of claim 13, further comprising:

assigning a time-stamp to a data segment stored in the local read cache;

assigning a time-stamp to a data segment stored in the remote Data Server;

upon receipt of a request to determine the validity of the data in the local read cache, comparing the time-stamp of the data segment stored in the local read cache with the time-stamp of a comparable data segment stored in the remote Data Server to determine whether the data segment in the local read cache is older than the comparable data segment on the remote data server; and

if the data segment in the local read cache is older than the comparable data segment on the remote data server, designating as invalid the data segment in the local read cache.

15. The method of claim 14, further comprising:

if the data segment in the local read cache is designated invalid, then transmitting the read access request to the remote Data Server for serving of the requested data; and

once the requested data is transmitted from the remote Data Server, storing a copy of the requested data in the local read cache and updating the respective time-stamps.

16. In a switching system connectable to at least first and second Client Servers, each of the first and second Client Servers being operable to communicate with (1) respective local clients and (2) a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the switching system being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a method of accelerating response to write access requests by clients, the method comprising:

providing, for each of the first and second Client Servers, a respective local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

providing, for each of the first and second Client Servers, a respective local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

receiving a write request from a client in communication with the first or second Client Server;

in response to receipt of the write request, checking the respective local read cache for a data segment match, and if a matching data segment is detected, invalidating the matching data segment;

checking the respective local write cache for a data segment match, and if a matching write segment is detected, invalidating or reusing the matching write segment;

transmitting to the remote Data Server a request to determine whether the write segment is available for writing, and if the segment is unavailable, waiting for the write segment to become available;

generating a new write cache entry representing the write data segments to be written; and

transmitting to the remote Data Server a request to unlock the data segments to be written.

17. The method of claim 16 further comprising:

determining whether data segments are available for writing by the first Client Server by checking whether the data segments are being written or otherwise are locked by the second Client Server during the time the first Client Server requests write access to the same or overlapping data segments.

18. The method of claim 17 wherein the determining further comprises generating a lock request on the requested data segment if the segment is available.

19. In a digital network having at least first and second Client Servers, each of the first and second Client Servers being operable to communicate with (1) respective local clients and (2) a remote Data Server to request access to data files on storage devices connected to the remote Data Server, the network being operable to provide mediation between storage and networking protocols used for communication between clients, servers and storage devices, a system for accelerating read access to data by clients, the system comprising:

means for providing, for each of the first and second Client Servers, a respective local read cache operable to communicate with the Client Server, operable to store a copy of recently read data;

means for providing, for each of the first and second Client Servers, a respective local write cache operable to communicate with the Client Server, operable to store a copy of data to be written;

means for receiving a read access request from a client in communication with the first or second Client Server;

means for, in response to receipt of the read access request, checking the local write cache for a data segment match;

if no data segment match is found in the local write cache, checking the local read cache for a data segment match;

if the segment is found in the local cache, transmitting to the remote Data Server a request to determine the validity of the data in the local read cache, thereby to determine whether the data in the local read cache must be updated from the remote Data Server,

if the data in the local read cache is not valid, or if no data segment match is found in the local read cache, transmitting the read access request to the remote Data Server for serving of the requested data; and

means for, once the requested data is transmitted from the remote Data Server, storing a copy of the requested data in the local read cache.