Application continuous high availability solution

Patent metadata

Field	Value
Publication number	US-11036530-B2
Application number	US-201615294799-A
Country	US
Kind code	B2
Filing date	Oct 17, 2016
Priority date	Oct 17, 2016
Publication date	Jun 15, 2021
Grant date	Jun 15, 2021

Abstract

A method for a secondary host to support continuous availability for an application on a primary virtual machine on a primary host is disclosed. The method includes the secondary host creating a secondary virtual machine that is identical to the primary virtual machine, the secondary host receiving activities of the primary virtual machine from the primary host, the secondary host buffering the activities, and the secondary host determining if the buffered activities are safe to replay. When the buffered activities are determined to be safe to replay, the method includes the secondary host replaying the buffered activities to the secondary virtual machine. When the buffered activities are determined to be unsafe to replay, the method includes the secondary host discarding the buffered activities and setting the secondary virtual machine as a new primary virtual machine to take over a service provided by the application.

First claim

We claim:

1. A method for a secondary host to support continuous availability for an application on a primary virtual machine on a primary host, comprising:
the secondary host synchronizing, by a secondary fault tolerance (FT) agent of a hypervisor of the secondary host, a secondary virtual machine on the secondary host with the primary virtual machine, wherein the secondary virtual machine is matched with the primary virtual machine in a fault tolerance pair, the secondary virtual machine is a replica of the primary virtual machine;
the secondary host receiving, by the secondary FT agent, activities of the primary virtual machine from the primary host;
the secondary host buffering, by the secondary FT agent, the activities in a first buffer before replaying the activities to the secondary virtual machine from a second buffer;
the secondary host determining if the buffered activities are safe to replay;
in response to receiving, by a secondary high availability (HA) agent of the hypervisor of the secondary host from a primary HA agent of the primary host, a heartbeat from the application in a time interval indicating that the application on the primary host is healthy, the secondary host determining, by the secondary HA agent, the buffered activities to be safe to replay and replaying, by the secondary FT agent, the buffered activities from the second buffer to the secondary virtual machine; and
in response to failing to receive, by the secondary HA agent from the primary HA agent, the heartbeat in the time interval, the secondary host determining, by the secondary HA agent, the buffered activities to be unsafe to replay, discarding, by the secondary FT agent, the buffered activities before the buffered activities can be replayed to the secondary virtual machine and setting, by the secondary FT agent, the secondary virtual machine as a new primary virtual machine to take over a service provided by the application.

2. The method of claim 1 , wherein determining if the buffered activities are safe to replay comprises the secondary host monitoring heartbeats of the application and determining if any of the heartbeats have arrived from the primary host in the time interval.

3. The method of claim 1 , wherein:
the first buffer and the second buffer are included in a double buffer;
buffering the activities comprises the secondary host saving the activities in the first buffer; and
replaying the buffered activities comprises the secondary host flipping the double buffer to replay the buffered activities from the second buffer and save new activities of the primary virtual machine in the first buffer.

4. The method of claim 1 , further comprising:
the primary host monitoring heartbeats of the application; and
when the primary host receives any of the heartbeats from the application in the time interval, forwarding the heartbeat to the secondary host.

5. The method of claim 4 , further comprising:
when the primary host does not receive the heartbeat from the application in the time interval, declaring the primary virtual machine as failed; and
when the buffered activities are determined to be unsafe to replay, the secondary host selecting a new secondary host to create a new secondary virtual machine.

6. The method of claim 1 , further comprising:
the application enabling the primary host to perform heartbeat monitoring on the application; and
the application periodically sending heartbeats to the primary host at a heartbeat interval.

7. The method of claim 1 , further comprising:
in response to receiving the heartbeat in the time interval indicating that the application on the primary host is healthy, replaying the buffered activities to the secondary virtual machine while preserving at least active network connections of the primary virtual machine.

8. A non-transitory, computer-readable storage medium encoded with instructions executable by a processor of a secondary host to support continuous availability for an application on a primary virtual machine on a primary host, the instructions comprising:
the secondary host synchronizing, by a secondary fault tolerance (FT) agent of a hypervisor of the secondary host, a secondary virtual machine on the secondary host with the primary virtual machine, wherein the secondary virtual machine is matched with the primary virtual machine in a fault tolerance pair, the secondary virtual machine is a replica of the primary virtual machine;
the secondary host receiving, by the secondary FT agent, activities of the primary virtual machine from the primary host;
the secondary host buffering, by the secondary FT agent, the activities in a first buffer before replaying the activities to the secondary virtual machine from a second buffer;
the secondary host determining if the buffered activities are safe to replay;
in response to receiving, by a secondary high availability (HA) agent of a hypervisor of the secondary host from a primary HA agent of the primary host, a heartbeat from the application in a time interval indicating that the application on the primary host is healthy, the secondary host determining, by the secondary HA agent, the buffered activities to be safe to replay, and replaying, by the secondary FT agent, the buffered activities from the second buffer to the secondary virtual machine; and
in response to failing to receive, by the secondary HA agent from the primary HA agent, the heartbeat in the time interval, the secondary host determining, by the secondary HA agent, the buffered activities to be unsafe to replay, discarding, by the secondary FT agent, the buffered activities before the buffered activities can be replayed to the secondary virtual machine and setting, by the secondary FT agent, the secondary virtual machine as a new primary virtual machine to take over a service provided by the application.

9. The storage medium of claim 8 , wherein determining if the buffered activities are safe to replay comprises the secondary host monitoring heartbeats of the application and determining if any of the heartbeats have arrived from the primary host in a time interval.

10. The storage medium of claim 8 , wherein:
the first buffer and the second buffer are included in a double buffer;
buffering the activities comprises the secondary host saving the activities in the first buffer; and
replaying the buffered activities comprises the secondary host flipping the double buffer to replay the buffered activities from the second buffer and save new activities of the primary virtual machine in the first buffer.

11. The storage medium of claim 8 , wherein the instructions further comprises:
the primary host monitoring heartbeats of the application; and
when the primary host receives the heartbeat from the application in the time interval, forwarding the heartbeat to the secondary host.

12. The storage medium of claim 11 , wherein the instructions further comprises:
when the primary host does not receive the heartbeat from the application in the time interval, declaring the primary virtual machine as failed; and
when the buffered activities are determined to be unsafe to replay, the secondary host selecting a new secondary host to create a new secondary virtual machine.

13. The storage medium of claim 8 , wherein the instructions further comprises:
the application enabling the primary host to perform heartbeat monitoring on the application; and
the application periodically sending heartbeats to the primary host at a heartbeat interval.

14. A system, comprising:
a primary host, comprising:
a hypervisor comprising a primary high availability (HA) agent and a primary

Assignees

• Vmware Inc

Inventors

• Shang Jingliang
• Lu Kecheng

Classifications

• H04L43/20

  the monitoring system or the monitored elements being virtualised, abstracted or software-defined entities, e.g. SDN or NFV · CPC title

• H04L43/10

  Active monitoring, e.g. heartbeat, ping or trace-route · CPC title

• G06F2009/45591

  Monitoring or debugging support · CPC title

• G06F9/45558 Primary

  Hypervisor-specific management and integration aspects · CPC title

• G06F11/07

  Responding to the occurrence of a fault, e.g. fault tolerance · CPC title