Environmental aware witness for active-active storage cluster nodes
The system, devices, and methods disclosed herein relate to a dynamic, robust method for choosing a “winner” in an active-active data storage network. In the systems and methods disclosed herein, two or more intelligent nodes within an active-active data storage network periodically exchange operational parameters in an ongoing negotiation regarding who should be the winner in the event of a communication failure within the network. The winner is chosen dynamically based on the operational parameters. A witness is kept apprised of the winner. In the event of a communication failure between the two nodes, the winner is chosen by the witness based on the most recently negotiated lock file reported by one or both of the nodes.
1. A method for dynamically assigning a winning node in an active-active data storage network comprising the steps of:
sending a first operational parameter from a first node to a second node;
sending a second operational parameter from the second node to the first node, the first and second nodes being part of an active-active data storage network;
negotiating between the first and second nodes which would be the winner in the event a quality measurement of a communication link between the first and second nodes falls below a threshold value, wherein the negotiation includes evaluating the first and second operational parameters;
choosing a winner based on at least the first and second operational parameters;
recording a winner in a lock file; and
transmitting the lock file to a witness.
2. The method of claim 1 , wherein the first operational parameter and the second operation parameter correspond to an equivalent parameter as between the first node and the second node.
3. The method of claim 1 , wherein the first operational parameter or the second operational parameter is a measure of a cache availability.
4. The method of claim 1 , wherein the first operational parameter is a health measurement for the first node.
5. The method of claim 1 , wherein the second operational parameter is a health measurement for the second node.
6. The method of claim 1 , wherein the first operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state for the first node.
7. The method of claim 1 , wherein the second operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state, for the second node.
8. A system for managing an active-active distributed data processing network, comprising:
a first intelligent storage node and a second intelligent storage node in an active-active network configuration connected via a communication link, wherein the first intelligent storage node and the second intelligent storage node are configured to monitor a quality measurement of the communication link;
a witness node communicatively coupled to the first intelligent storage node and the second intelligent storage node; and
a processor having logic stored thereon configured to:
send a first operational parameter from a first node to a second node;
send a second operational parameter from the second node to the first node, the first and second nodes being part of an active-active data storage network;
negotiate between the first and second nodes which would be the winner in the event a quality measurement of a communication link between the first and second nodes falls below a threshold value, wherein the negotiation includes evaluating the first and second operational parameters;
choose a winner based on at least the first and second operational parameters;
record a winner in a lock file; and
transmit the lock file to a witness.
9. The system of claim 8 , wherein the first operational parameter and the second operation parameter correspond to an equivalent parameter as between the first node and the second node.
10. The system of claim 8 , wherein the first operational parameter or the second operational parameter is a measure of a cache availability.
11. The system of claim 8 , wherein the first operational parameter is a health measurement for the first node.
12. The system of claim 8 , wherein the second operational parameter is a health measurement for the second node.
13. The system of claim 8 , wherein the first operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state for the first node.
14. The system of claim 8 , wherein the second operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state for the second node.
15. A non-transitory computer readable storage medium containing software for dynamically assigning a winning node in an active-active data storage network comprising performing the steps of:
sending a first operational parameter from a first node to a second node;
sending a second operational parameter from the second node to the first node, the first and second nodes being part of an active-active data storage network;
negotiating between the first and second nodes which would be the winner in the event a quality measurement of a communication link between the first and second nodes falls below a threshold value, wherein the negotiation includes evaluating the first and second operational parameters;
choosing a winner based on at least the first and second operational parameters;
recording a winner in a lock file; and
transmitting the lock file to a witness.
16. The non-transitory computer readable storage medium of claim 15 , wherein the first operational parameter and the second operation parameter correspond to an equivalent parameter as between the first node and the second node.
17. The non-transitory computer readable storage medium of claim 15 , wherein the first operational parameter or the second operational parameter is a measure of a cache availability.
18. The non-transitory computer readable storage medium of claim 15 , wherein the first operational parameter is a health measurement for the first node.
19. The non-transitory computer readable storage medium of claim 15 , wherein the second operational parameter is a health measurement for the second node.
20. The non-transitory computer readable storage medium of claim 15 , wherein the first operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state for the first node, or the second operational parameter is a synchronous communication connection to a third storage node, an asynchronous communication connection to a third storage node, a bias role, a non-bias role, a data replication pathway, a memory board state, or a faulted hardware state for the second node.