System and method for communicating a software-generated pulse waveform between two servers in a network

• US 7,444,537 B2
• Filed: 05/09/2005
• Issued: 10/28/2008
• Est. Priority Date: 05/13/1997
• Status: Expired due to Fees

• Current Assignee: Round Rock Research LLC
• Original Assignee: Micron Technology, Inc.
• Inventors: Chrabaszcz, Michael, Findlay, Bruce
• Primary Examiner(s): Bonzo; Bryce P
• Application Number:
  US11/124,769
• Publication Number:
  US 20050229024A1
• Time in Patent Office: 1,268 Days
• Field of Search: 714/4, 714/5, 714/42
• US Class Current: 714/4.5
• CPC Class Codes: G06F 11/0709 in a distributed system consisting of a plurality of standalone computer nodes, e.g. clusters, client-server systems
• CPC Class Codes: G06F 11/0745 in an input/output transactions management context input/output processing in general G06F13/00
• CPC Class Codes: G06F 11/0757 by exceeding a time limit, i.e. time-out, e.g. watchdogs
• CPC Class Codes: G06F 11/0772 Means for error signaling, e.g. using interrupts, exception flags, dedicated error registers
• CPC Class Codes: G06F 11/3006 where the computing system is distributed, e.g. networked systems, clusters, multiprocessor systems multiprogramming arrangements G06F9/46; allocation of resources G06F9/50
• CPC Class Codes: G06F 11/3034 where the computing system component is a storage system, e.g. DASD based or network based digital input from or digital output to record carriers G06F3/06; digital recording or reproducing G11B20/18; 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], H04L67/1097
• CPC Class Codes: G06F 11/3048 where the topology of the computing system or computing system component explicitly influences the monitoring activity, e.g. serial, hierarchical systems
• CPC Class Codes: G06F 11/3055 Monitoring arrangements for monitoring the status of the computing system or of the computing system component, e.g. monitoring if the computing system is on, off, available, not available error or fault processing without redundancy G06F11/0703; error detection or correction by redundancy in data representation G06F11/08; error detection or correction by redundancy in operation G06F11/14; error detection or correction by redundancy in hardware G06F11/16
• CPC Class Codes: G06F 11/3065 Monitoring arrangements determined by the means or processing involved in reporting the monitored data error or fault reporting or logging G06F11/0766
• CPC Class Codes: H04L 41/06 Management of faults, events, alarms or notifications
• CPC Class Codes: H04L 41/12 Discovery or management of network topologies
• CPC Class Codes: H04L 43/0805 by checking availability
• CPC Class Codes: H04L 43/0817 by checking functioning
• CPC Class Codes: H04L 43/10 Active monitoring, e.g. heartbeat, ping or trace-route
• CPC Class Codes: H04L 67/1095 Replication or mirroring of data, e.g. scheduling or transport for data synchronisation between network nodes
• CPC Class Codes: H04L 69/40 for recovering from a failure of a protocol instance or entity, e.g. service redundancy protocols, protocol state redundancy or protocol service redirection management of faults, events, alarms or notifications in data switching networks H04L41/06

Abstract

A method of monitoring a status condition of a first server with a second server in a server network, and also providing synchronization and messaging between the two servers, the method including: transmitting a software-generated pulse waveform from the first server to a device coupled to the first server, wherein the software-generated pulse waveform is comprises a first command corresponding to a logic level low and a second command corresponding to a logic level high; setting said device to a first state during logic level lows of said pulse waveform and to a second state during logic level highs of said pulse waveform; receiving the software-generated pulse waveform with the second server by determining when said device is in the first state and when it is in the second state; and determining when said device no longer changes from the first state to the second state. In order to provide synchronization and messaging, said pulse waveform is frequency modulated in order to communicate specified commands and/or reference points between the two servers.

Claims

1. A method of determining the status of a server comprising:

transmitting status commands from a server to a device which is coupled to the server, wherein the status commands comprise reserve and release commands; and

determining whether the server is operational based on the status of the device.

2. The method of claim 1 wherein a constant device status indicates that the server has failed.

3. The method of claim 1 wherein a changing device status indicates that the server is active.

4. The method of claim 1 further comprising transferring control of a least one network resource from the server to a second server based on the status of the device.

5. The method of claim 1 wherein the status commands comprise a pulse waveform.

6. The method of claim 1 wherein the device is a SCSI device.

7. An apparatus for determining the status of a server, comprising:

status commands transmitted from a server to a device which is coupled to the server; and

a device status generated by the device in response to the status commands, wherein the device status indicates the status of the server, and wherein the device is a SCSI device.

8. The apparatus of claim 7 wherein a changing device status indicates that the server is operational.

9. The apparatus of claim 7 wherein a constant device status indicates that the server has failed.

10. The apparatus of claim 7 wherein control of a least one network resource is assigned from the server to a second server based on the device status.

11. The apparatus of claim 7 wherein the status commands comprise a pulse waveform.

12. The apparatus of claim 7 wherein the status commands comprise reserve and release commands.

13. An apparatus that determines the status of a server, comprising:

means for transmitting status commands from a server to a device which is coupled to the server, wherein the status commands comprise reserve and release commands; and

means for determining whether the server is operational based on the status of the device.

14. The apparatus of claim 13 wherein the status commands comprise a pulse waveform.

15. The apparatus of claim 13 wherein the server is operational if the device status changes.

16. The apparatus of claim 13 wherein the server has failed if the device status is constant.

17. The apparatus of claim 13 wherein control of a least one network resource is assigned from the server to a second server based on the status of the device.

18. The apparatus of claim 13 wherein the device is a SCSI device.