System for power savings in server farms

• US 20070130341A1
• Filed: 12/06/2005
• Published: 06/07/2007
• Est. Priority Date: 12/06/2005
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Ma, Kevin
• Granted Patent: US 7,756,972 B2
• Time in Patent Office: Days
• US Class Current: 709/226
• CPC Class Codes: G06F 1/26 Power supply means, e.g. regulation thereof for memories G11C
• CPC Class Codes: G06F 1/3203 Power management, i.e. event-based initiation of a power-saving mode
• CPC Class Codes: G06F 2209/5011 Pool
• CPC Class Codes: G06F 9/5061 Partitioning or combining of resources
• CPC Class Codes: G06F 9/5094 where the allocation takes into account power or heat criteria power management in computers in general G06F1/3203; thermal management in computers in general G06F1/206
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• CPC Class Codes: H04L 67/1008 based on parameters of servers, e.g. available memory or workload monitoring of computer activity G06F11/30
• CPC Class Codes: H04L 67/1012 based on compliance of requirements or conditions with available server resources
• CPC Class Codes: H04L 67/1017 based on a round robin mechanism
• CPC Class Codes: H04L 67/1023 based on a hash applied to IP addresses or costs
• CPC Class Codes: H04L 67/1029 using data related to the state of servers by a load balancer
• CPC Class Codes: H04L 67/1031 Controlling of the operation of servers by a load balancer, e.g. adding or removing servers that serve requests
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

A threshold-based approach is used to assign tasks to servers in a server farm. A “number of connections” count or “connection rate” is maintained for an active server and when the count achieves a first value a wake up signal is sent to a next (inactive) server to alert the inactive server to become active and periodic keep alive signals are initiated. When the number of connections next reaches a second, higher value, subsequent requests for connections are sent to the newly active server. Variations of this approach allow for servers and their associated processes and devices to be handled in clusters for power management scaling efficiency. Servers can be placed in the inactive mode when the number of connections reaches a lower threshold. Other criteria can be used to determine activation of servers, processors or other devices or processes. Other types of resource use monitoring can also be used with this invention.

Claims

1. A method for controlling power consumption of a server, wherein the server includes a digital processing system, the method comprising:

setting a limit of resource use for a first active server;

measuring the resource use of the first active server;

receiving a request for additional resource use; and

when the measured resource use of the first active server plus the request for additional resource are in a predetermined relationship with the set limit then

placing an inactive server into an active state as a second active server; and

assigning requests for additional resource use to the second active server.

2. The method of claim 1, wherein a resource use includes a network connection request.

3. The method of claim 2, wherein the network connection request includes a request for web page content.

4. The method of claim 2, wherein the network connection request includes a request for data from a database.

5. The method of claim 1, wherein the resource use includes a connection rate, wherein measuring the resource use includes measuring a current connection rate, the method further comprising:

determining a threshold connection rate for the first server; and

detecting when incoming requests for additional connections would exceed a predetermined threshold limit.

6. The method of claim 1, further comprising:

setting a pre-active threshold relative to the predetermined relationship; and

initiating placement of the inactive server into the active state as the second active server in response to the measured resource use of the first active server achieving the pre-active threshold.

7. The method of claim 6, wherein the measured resource use of the first active server includes a connection rate, wherein the pre-active threshold includes a rate that is less than a predetermined connection rate, wherein initiating placement of the inactive server includes:

sending a WOL signal to the inactive server.

initiating periodic keep alives to the newly active server

8. The method of claim 1, further comprising:

setting an inactive threshold;

measuring a resource use of the second active server; and

placing the second active server into an inactive state when the measured resource use of the second active server achieves a predetermined relationship to the inactive threshold.

9. The method of claim 8, wherein the inactive threshold includes a rate of connections, the method further comprising:

measuring a rate of current connections of the second active server; and

placing the second active server into an inactive state when the rate of current connections of the second active server achieves the inactive threshold number.

10. The method of claim 1, wherein the first and second active servers each include a cluster of servers.

11. The method of claim 1, wherein each server has associated devices, the method further comprising:

placing devices associated with a particular computer into an active state when the particular server is placed into an active state, and placing the devices into an inactive state when the particular server is placed into an inactive state.

12. The method of claim 1, wherein a system includes multiple levels, wherein multiple servers are included in each level, the method further comprising:

assigning different weights to two or more of the levels; and

using the different weights to determine the predetermined relationship with the set limit, wherein a decision to place any servers in a particular level into an active state includes use of a weight associated with the particular level.

13. A method for managing power among servers in a server farm, the method executing in a load balancing device, wherein the load balancing device is coupled with the servers, the method comprising:

predetermining a threshold limit on the number of connections for a first server in the server farm;

monitoring the first server to determine when a number of connections being handled by the first server is near the threshold limit;

activating a second server from a low-power state to the active state when the first server'"'"'s number of connections is near the threshold limit, wherein a particular server in the low-power state consumes energy at a lower rate than the particular server in the active state;

assigning connections to the second server;

monitoring the second server to determine when its number of connections falls below a lower limit; and

in response to the second server'"'"'s connections falling below the lower limit, placing the second server into the low-power state.

14. An apparatus for controlling power to servers, the apparatus comprising:

a processor coupled to a plurality of servers;

a machine-readable medium coupled to the processor, wherein the machine-readable medium includes one or more instructions executable by the processor for;

setting a limit of resource use for a first active server;

measuring the resource use of the first active server;

receiving a request for additional resource use; and

when the measured resource use of the first active server plus the request for additional resource are in a predetermined relationship with the set limit then

placing an inactive server into an active state as a second active server; and

assigning the request for additional resource use to the second active server.

15. A machine-readable medium including instructions executable by a processor, the machine-readable medium comprising:

one or more instructions for setting a limit of resource use for a first active server;

one or more instructions for measuring the resource use of the first active server;

one or more instructions for receiving a request for additional resource use; and

one or more instructions for when the measured resource use of the first active server plus the request for additional resource are in a predetermined relationship with the set limit then

placing an inactive server into an active state as a second active server; and

assigning the request for additional resource use to the second active server.

16. A method for controlling power consumption of servers in a group of servers, the method comprising:

assigning servers to an active pool or an inactive pool;

setting a limit of resource use for the active pool;

measuring the resource use of the active pool;

receiving a request for additional resource use; and

when the measured resource use of the active pool plus the request for additional resource are in a predetermined relationship with the set limit then

placing at least one server from the inactive pool into the active pool; and

subsequent to the step of placing at least one server from the inactive pool into the active pool

assigning requests for additional resource use to the active pool.

17. The method of claim 16, wherein a resource use includes a network connection request.

18. The method of claim 17, wherein the network connection request includes a request for web page content.

19. The method of claim 17, wherein the network connection request includes a request for data from a database.

20. The method of claim 16, wherein the resource use includes a connection rate, wherein measuring the resource use includes measuring a current connection rate, the method further comprising:

determining a threshold connection rate for the active pool; and

detecting when incoming requests for additional connections would exceed a predetermined threshold limit.