Policy-driven storage in a microserver computing environment

• US 10,585,830 B2
• Filed: 01/12/2018
• Issued: 03/10/2020
• Est. Priority Date: 12/10/2015
• Status: Active Grant

• Current Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Original Assignee: Cisco Technology, Inc. (Cisco Systems, Inc.)
• Inventors: Sajeepa, Prabhath, Borikar, Sagar
• Primary Examiner(s): Alrobaye, Idriss N
• Assistant Examiner(s): Modo, Ronald T
• Application Number:
  US15/869,256
• Publication Number:
  US 20180137073A1
• Time in Patent Office: 788 Days
• CPC Class Codes: G06F 13/1631 through address comparison
• CPC Class Codes: G06F 13/24 using interrupt G06F13/32 takes precedence
• CPC Class Codes: G06F 13/385 for adaptation of a particular data processing system to different peripheral devices
• CPC Class Codes: G06F 13/4022 using switching circuits, e.g. switching matrix, connection or expansion network G06F13/4009 takes precedence
• CPC Class Codes: G06F 13/4282 on a serial bus, e.g. I2C bus, SPI bus on daisy chain buses G06F13/4247
• CPC Class Codes: Y02D 10/00 Energy efficient computing, e.g. low power processors, power management or thermal management

Abstract

An example method for facilitating policy-driven storage in a microserver computing environment is provided and includes receiving, at an input/output (I/O) adapter in a microserver chassis having a plurality of compute nodes and a shared storage resource, policy contexts prescribing storage access parameters of respective compute nodes and enforcing the respective policy contexts on I/O operations by the compute nodes, in which respect a particular I/O operation by any compute node is not executed if the respective policy context does not allow the particular I/O operation. The method further includes allocating tokens to command descriptors associated with I/O operations for accessing the shared storage resource, identifying a violation of any policy context of any compute node based on availability of the tokens, and throttling I/O operations by other compute nodes until the violation disappears.

Claims

1. A method for managing policy contexts prescribing storage access parameters of respective compute nodes within a microserver chassis comprising a plurality of compute nodes, a shared storage resource, and an input/output (I/O) adapter, the method comprising:

allocating tokens to command descriptors associated with I/O operations for accessing the shared storage resource;

identifying a violation of any policy context of any of the compute nodes based on availability of the tokens;

receiving at a Small Computer System Interface network interface card (sNIC) of the I/O adapter, an SCSI packet generated by one of the compute nodes, the sNIC being uniquely associated with the one of the compute nodes, the I/O operations by the one of the compute nodes comprising a SCSI command; and

encapsulating, at the sNIC, an SCSI packet in an Ethernet packet comprising a fake preset destination address and source address in an Ethernet header;

throttling I/O operations by other of the compute nodes until the violation disappears.

2. The method of claim 1, further comprising programming a packet classifier in the I/O adapter to filter storage traffic local to the micro server chassis.

3. The method of claim 1, further comprising populating a flow table in the I/O adapter with actions according to the any policy context.

4. The method of claim 1, wherein throttling I/O operations by other compute nodes comprises executing a frequency throttler comprising a thread of instructions, wherein the throttling identifies sNICs associated with respective compute nodes that are throttleable based on respective policy contexts associated with their corresponding compute nodes, adds the identified sNICs to a list of throttled sNICs, and changes a context state in corresponding policy contexts associated with the identified sNICs to indicate that I/O operations are paused, wherein no tokens are awarded to the paused sNICs.

5. The method of claim 1, further comprising:

filtering, at a packet classifier of the I/O adapter, the Ethernet header based on the fake preset destination address and source address, wherein the packet classifier returns a key based on the filtering;

indexing into a flow table in the I/O adapter with the key, the flow table comprising a plurality of flow table entries specifying respective actions, at least one of the respective actions including calling an arbiter routine that varies according to a type of the SCSI packet; and

executing the arbiter routine.

6. The method of claim 1, wherein identifying the violation comprises executing a periodic sampler comprising a thread of instructions, wherein the periodic sampler samples flow table entries in the I/O adapter, determines whether sNICs associated with respective compute nodes are marked as starved, and identifies as the violation any sNIC marked as starved for unavailability of the tokens.

7. A non-transitory tangible computer readable media that includes instructions for execution, which when executed by a processor, performs operations comprising:

allocating tokens to command descriptors associated with I/O operations for accessing a shared storage resource of a microserver chassis, the microserver chassis including a plurality of compute nodes;

identifying a violation of any policy context of any of the compute nodes based on availability of the tokens, comprising;

receiving at a Small Computer System Interface network interface card (sNIC) of the I/O adapter, an SCSI packet generated by one of the compute nodes, the sNIC being uniquely associated with the one of the compute nodes, the I/O operations by the one of the compute nodes comprising a SCSI command;

encapsulating, at the sNIC, an SCSI packet in an Ethernet packet comprising a fake preset destination address and source address in an Ethernet header; and

throttling I/O operations by other of the compute nodes until the violation disappears.

8. The media of claim 7, the operations further comprising programming a packet classifier in an I/O adapter of the microserver chassis to filter storage traffic local to the microserver chassis.

9. The media of claim 7, the operations further comprising populating a flow table in an I/O adapter of the microserver chassis with actions according to the any policy context.

10. The media of claim 7, wherein throttling I/O operations by other compute nodes comprises executing a frequency throttler comprising a thread of instructions, wherein the throttling identifies sNICs associated with respective compute nodes that are throttleable based on respective policy contexts associated with their corresponding compute nodes, adds the identified sNICs to a list of throttled sNICs, and changes a context state in corresponding policy contexts associated with the identified sNICs to indicate that I/O operations are paused, wherein no tokens are awarded to the paused sNICs.

11. The media of claim 7, the operations further comprising:

filtering, at a packet classifier of the I/O adapter, the Ethernet header based on the fake preset destination address and source address, wherein the packet classifier returns a key based on the filtering;

indexing into a flow table in the I/O adapter with the key, the flow table comprising a plurality of flow table entries specifying respective actions, at least one of the respective actions including calling an arbiter routine that varies according to a type of the SCSI packet; and

executing the arbiter routine.

12. The media of claim 7, wherein identifying the violation comprises executing a periodic sampler comprising a thread of instructions, wherein the periodic sampler samples flow table entries in an I/O adapter of the microserver chassis, determines whether sNICs associated with respective compute nodes are marked as starved, and identifies as the violation any sNIC marked as starved for unavailability of the tokens.

13. An apparatus comprising:

a microserver chassis including a plurality of compute nodes;

a shared storage resource;

an Its adapter facilitating access by the compute nodes to the shared storage resource over a shared transmission medium; and

at least one processor, wherein the processor executes instructions, the apparatus is configured to perform operations including;

allocating tokens to command descriptors associated with I/O operations for accessing the shared storage resource;

identifying a violation of any policy context of any of the compute nodes based on availability of the tokens;

receiving at a Small Computer System Interface network interface card (sNIC) of the I/O adapter, an SCSI packet generated by one of the compute nodes, the sNIC being uniquely associated with the one of the compute nodes, the I/O operations by the one of the compute nodes comprising a SCSI command;

encapsulating, at the sNIC, an SCSI packet in an Ethernet packet comprising a fake preset destination address and source address in an Ethernet header; and

throttling I/O operations by other of the compute nodes until the violation disappears.

14. The apparatus of claim 13, the operations further comprising programming a packet classifier in the I/O adapter to filter storage traffic local to the microserver chassis.

15. The apparatus of claim 13, the operations further comprising populating a flow table in the I/O adapter with actions according to the any policy context.

16. The apparatus of claim 13, wherein throttling I/O operations by other compute nodes comprises executing a frequency throttler comprising a thread of instructions, wherein the throttling identifies sNICs associated with respective compute nodes that are throttleable based on respective policy contexts associated with their corresponding compute nodes, adds the identified sNICs to a list of throttled sNICs, and changes a context state in corresponding policy contexts associated with the identified sNICs to indicate that I/O operations are paused, wherein no tokens are awarded to the paused sNICs.

17. The apparatus of claim 13, wherein identifying the violation comprises executing a periodic sampler comprising a thread of instructions, wherein the periodic sampler samples flow table entries in the I/O adapter, determines whether sNICs associated with respective compute nodes are marked as starved, and identifies as the violation any sNIC marked as starved for unavailability of the tokens.