Dynamic command filter

• US 20040139134A1
• Filed: 01/15/2003
• Published: 07/15/2004
• Est. Priority Date: 01/15/2003
• Status: Active Grant

• Current Assignee: Hewlett Packard Enterprise Development LP (Hewlett-Packard Enterprise Company)
• Original Assignee: Hewlett-Packard Company (HP Inc.)
• Inventors: DiCorpo, Jeffery, Feather, Stanley Smith Jr.
• Granted Patent: US 7,349,997 B2
• Time in Patent Office: Days
• US Class Current: 708/300
• CPC Class Codes: G06F 11/3433 for load management allocation of a server based on load conditions G06F9/505; load rebalancing G06F9/5083; redistributing the load in a network by a load balancer H04L67/1029
• CPC Class Codes: G06F 11/348 Circuit details, i.e. tracer hardware
• CPC Class Codes: G06F 11/349 for interfaces, buses
• 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]
• CPC Class Codes: H04L 67/56 Provisioning of proxy services store-and-forward switching systems in data switching networks H04L12/54
• CPC Class Codes: H04L 67/563 Data redirection of data network streams
• CPC Class Codes: H04L 67/5682 Policies or rules for updating, deleting or replacing the stored data
• CPC Class Codes: H04L 67/59 Providing operational support to end devices by off-loading in the network or by emulation, e.g. when they are unavailable
• CPC Class Codes: H04L 67/63 Routing a service request depending on the request content or context
• CPC Class Codes: H04L 69/329 in the application layer [OSI layer 7]
• CPC Class Codes: H04L 9/40 Network security protocols

Abstract

A filter comprises a first device, a second device, a dynamic filter, and a device monitor. The dynamic filter is coupled to the first device and the second device, and selectively directs commands to the first device and to the second device based on dynamic status of the first device. The device monitor is coupled to the dynamic filter and to the first device and capable of determining the first device dynamic status.

Claims

1. A filter comprising:

a first device;

a second device;

a dynamic filter coupled to the first device and the second device, the dynamic filter selectively directing commands to the first device and to the second device based on dynamic status of the first device; and

a device monitor coupled to the dynamic filter and to the first device and capable of determining the first device dynamic status.

2. The filter according to claim 1 wherein:

the device monitor is capable of analyzing multiple conditions in a background process that extracts a device state parameter from the multiple conditions, the device state parameter for directing the dynamic filter.

3. The filter according to claim 1 wherein:

the dynamic filter selectively directs commands based on passively monitored traffic to the first device including command, task management, data, and status traffic.

4. The filter according to claim 1 wherein:

the dynamic filter selectively directs commands based on actively issued supplemental commands to the first device that refresh device information.

5. The filter according to claim 1 wherein:

the dynamic filter selectively directs commands based on intercepted incoming and/or outgoing traffic from the first device used to determine first device state.

6. The filter according to claim 1 further comprising:

the dynamic filter selectively directs commands based on intercepted incoming and/or outgoing traffic from the first device used for making a real-time determination of whether the first device is bound to a requesting device.

7. The filter according to claim 1 further comprising:

a data path capable of coupling the first device and the second device to a plurality of servers.

8. The filter according to claim 1 wherein:

the dynamic filter being capable of protecting state of the first device during successive data transfer and media movement operations.

9. The filter according to claim 1 wherein:

the second device is capable of emulating responses of the first device; and

the device monitor is capable of redirecting access from the second device to the first device when the first device becomes available.

10. A method of filtering commands comprising:

receiving a command directed to a first device;

dynamically determining state of the first device; and

selectively directing the command to the first device or to a second device based on the determined first device state.

11. The method according to claim 10 further comprising:

passively monitoring traffic to the first device including command, task management, data, and status traffic;

determining when the passively monitored traffic is insufficient for determining first device state; and

actively issuing supplemental commands to the first device to refresh device information if monitored traffic is insufficient.

12. The method of claim 10 further comprising:

presuming the first device is a preferred target device and the second device is used if the first device is unavailable.

13. The method of claim 10 further comprising:

filtering commands in a steady state comprising;

examining state of the first device;

if the first device is not available, routing the command to the second device;

if the first device is available, routing the command to the first device.

14. The method of claim 10 further comprising:

filtering commands in a steady state comprising;

sampling a command routed to the first device; and

passing the command to the first device.

15. The method of claim 10 further comprising:

filtering commands in a steady state comprising;

processing a command;

returning an output result in response to the command;

if the first device processes the command;

sampling the output result;

updating a first device status output signal; and

supplying the first device status output signal.

16. The method of claim 10 further comprising:

filtering commands in an initial state comprising;

setting a first device state;

generating a sequence of commands to the first device to determine a first device state; and

retaining the first device state without passage to other system components.

17. The method of claim 10 further comprising:

setting the first device state to ‘

ready’

or ‘

not ready’

based on the particular application.

18. The method of claim 10 further comprising:

filtering commands in the initial state comprising;

generating a result of a command performed by the first device;

updating the first device state based on the generated result to reflect actual first device state.

19. A filter comprising:

means for receiving a command directed to a first device;

means for dynamically determining state of the first device; and

means for selectively directing the command to the first device or to a second device based on the determined first device state.

20. An article of manufacture comprising:

a computer usable medium having computer readable program code means embodied therein for causing a processor to receive a command directed to a first device;

a computer readable program code means for causing the processor to dynamically determine state of the first device; and

a computer readable program code means for causing the processor to selectively direct the command to the first device or to a second device based on the determined first device state.

21. The article of manufacture according to claim 20 further comprising:

a computer readable program code means for causing the processor to passively monitor traffic to the first device including command, task management, data, and status traffic;

a computer readable program code means for causing the processor to determine when the passively monitored traffic is insufficient for determining first device state; and

a computer readable program code means for causing the processor to actively issue supplemental commands to the first device to refresh device information if monitored traffic is insufficient.

22. The article of manufacture according to claim 20 further comprising:

a computer readable program code means for causing the processor to presume the first device is a preferred target device and the second device is used if the first device is unavailable.