Systems and methods for providing a quiescing protocol

• US 20070195810A1
• Filed: 02/17/2006
• Published: 08/23/2007
• Est. Priority Date: 02/17/2006
• Status: Active Grant

• Current Assignee: Emc IP Holding Company LLC (Dell Technologies Inc.)
• Original Assignee: EMC Corporation (Dell Technologies Inc.)
• Inventors: Fachan, Neal
• Granted Patent: US 7,848,261 B2
• Time in Patent Office: Days
• US Class Current: 370/432
• CPC Class Codes: H04L 41/30 Decision processes by autonomous network management units using voting and bidding
• CPC Class Codes: H04L 67/1001 for accessing one among a plurality of replicated servers
• 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

Abstract

The systems and methods of the present invention provide a quiescing protocol. In one embodiment, nodes of a system utilize the protocol to complete processing until they reach a consistent state. In one embodiment, a coordinator initiates the quiescing process and the nodes communicate with each other to determine whether their messages have been processed and communicate with the coordinator to determine when all of the messages have been processed

Claims

1. A distributed system configured to process messages within the distributed system, the distributed system comprising:

a plurality of distributed nodes configured to permit communication among the plurality of nodes and to process messages;

at least one of the plurality of nodes acting as a coordinator, the coordinator configured to initiate a quiescing protocol and to determine whether relevant messages have been processed by the plurality of the distributed nodes.

2. The distributed system of claim 1, wherein each of the plurality of distributed nodes is configured to have the capability to act as the coordinator.

3. The distributed system of claim 1, wherein the coordinator is configured to initiate the quiescing protocol if the coordinator gains communication with a new distributed node.

4. The distributed system of claim 1, wherein the coordinator is configured to initiate the quiescing protocol if the coordinator loses communication with at least one of the plurality of nodes.

5. The distributed system of claim 1, wherein the plurality of nodes manages a set of resources and the messages relate to allocation of the set of resources.

6. A method of quiescing a set of messages processed within the system, the method comprising:

sending start messages to a plurality of nodes indicating that a quiescing protocol is to begin;

receiving checkpoint messages from the plurality of nodes indicating that the plurality of nodes have received their probe response messages;

sending continue messages to the plurality of nodes requesting received message information from the plurality of nodes;

receiving received message information from the plurality of nodes; and

determining that the received message information indicates that the plurality of nodes have not received any new messages.

7. The method of claim 6, wherein sending messages to the plurality of nodes includes sending local messages to at least one of the plurality of nodes.

8. The method of claim 6, sending done messages to the plurality of nodes indicating that the quiescing protocol is complete.

9. The method of claim 6, wherein sending messages to the plurality of nodes includes sending remote messages to at least one of the plurality of nodes.

10. The method of claim 6, wherein the plurality of nodes manages a set of resources and the received message information relates to messages for allocating the set of resources.

11. A storage medium having a computer program stored thereon for causing a suitably programmed system to process the computer program by performing the method of claim 6 when such computer program is executed on the system.

12. A system for quiescing a set of messages processed within the distributed system, the system comprising:

means for sending start messages to a plurality of nodes indicating that a quiescing protocol is to begin;

means for receiving checkpoint messages from the plurality of nodes indicating that the plurality of nodes have received their probe response messages;

means for sending continue messages to the plurality of nodes requesting received message information from the plurality of nodes;

means for receiving received message information from the plurality of nodes; and

means for determining that the received message information indicates that the plurality of nodes have not received any new messages.

13. A method of quiescing a distributed system, the method comprising:

setting a counter and counting messages that have been received;

ensuring that all messages previously sent have been processed by their destination;

performing a checkpoint; and

performing a second checkpoint using the value of the counter.

14. A method of quiescing a distributed system, the method comprising:

receiving a start message from a coordinator indicating that a quiescing protocol is to begin;

suspending new messages;

setting a received message information to indicate that there are no messages received;

receiving messages from the plurality of nodes;

updating the received message information to indicate that a message has been received;

sending probe messages to the plurality of nodes;

receiving probe response messages from the plurality of nodes;

receiving probe messages from the plurality of nodes;

for each probe message received from the plurality of nodes, sending corresponding probe response messages to the plurality of nodes;

sending a checkpoint message to the coordinator indicating that the probe response messages have been received from the plurality of nodes;

receiving a continue message from the coordinator requesting the received message information;

sending the received message information to the coordinator; and

receiving a done message from the coordinator.

15. The method of claim 14, wherein sending messages to the coordinator includes sending local messages to the coordinator.

16. The method of claim 14, wherein sending messages to the coordinator includes sending remote messages to the coordinator.

17. The method of claim 14, wherein sending probe messages to the plurality of nodes includes sending a local probe message.

18. The method of claim 14, wherein the plurality of nodes manages a set of resources and the messages received from the plurality of nodes relate to the allocation of the set of resources.

19. The method of claim 14, wherein suspending new messages includes suspending the generation of new messages.

20. A storage medium having a computer program stored thereon for causing a suitably programmed system to process the computer program by performing the method of claim 14 when such computer program is executed on the system.