Patching systems and applications in a virtualized environment

Patent metadata

Field	Value
Publication number	US-10296320-B2
Application number	US-201414482010-A
Country	US
Kind code	B2
Filing date	Sep 10, 2014
Priority date	Sep 10, 2014
Publication date	May 21, 2019
Grant date	May 21, 2019

Abstract

A method for updating an application executing on a virtual machine includes replicating the virtual machine to produce a replica, applying an update to the replica that is scheduled to be made to the virtual machine, in parallel with the applying, updating one of the virtual machine and the replica so that a state of the virtual machine matches a state of the replica, and continuing execution of the application on one of the virtual machine and the replica.

First claim

What is claimed is:

1. A method for updating an application executing on a virtual machine, wherein the virtual machine is one of a plurality of virtual machines on which the application is executing, the method comprising:
replicating the virtual machine to produce a replica;
applying a software update to the replica that is scheduled to be made to the virtual machine, without applying the software update to the virtual machine at the same time, before the software update is applied to the virtual machine;
in parallel with the applying, updating a state of one of the virtual machine and the replica so that a state of the virtual machine matches a state of the replica, wherein the updating comprises:
testing the replica after the applying;
saving user requests received by the virtual machine during the replicating and the applying into a queue, wherein the virtual machine continues to process the user requests during the replicating and the applying;
creating a mapping between those of the user requests that travel from a virtual machine of the plurality of virtual machines under a control of a first party to a virtual machine of the plurality of virtual machines under a control of a second party and corresponding responses to those of the user requests from the virtual machine of the plurality of virtual machines under the control of the second party to the virtual machine of the plurality of virtual machines under control of the first party;
replaying data flows between the virtual machine of the plurality of virtual machines under the control of the first party and the virtual machine of the plurality of virtual machines under the control of the second party in the replica, in accordance with the mapping;
replaying the user requests from the queue to the replica after the applying, until the queue is empty;
delivering new user requests received after the replaying to the virtual machine and to the replica until a predefined maintenance window arrives;
switching execution of the application from the virtual machine to the replica when the predefined maintenance window arrives; and
shutting down the virtual machine after the switching.

2. The method of claim 1 , wherein the replicating, the applying, and the updating are performed for each virtual machine of the plurality of virtual machines, resulting in a plurality of replicas.

3. The method of claim 2 , wherein the applying and the updating are performed for one replica of the plurality of replicas at a time.

4. The method of claim 2 , wherein the applying and the updating are performed for all replicas of the plurality of replicas at once.

5. The method of claim 2 , wherein the applying and the updating are performed for all replicas of a subset of the plurality of replicas at once.

6. The method of claim 1 , further comprising:
subsequent to the replicating, monitoring system calls in the virtual machine that set seeds for random value generation for session key generation;
recording the seeds; and
intercepting the system calls during the replaying, wherein the intercepting comprises providing the seeds.

7. The method of claim 6 , further comprising:
matching the seeds to one session of a plurality of sessions handled by the virtual machine, prior to the replaying.

8. A computer program product for updating an application executing on a virtual machine, wherein the virtual machine is one of a plurality of virtual machines on which the application is executing, the computer program product comprising a computer readable storage medium having program instructions embodied therewith, the program instructions executable by a processor to cause the processor to perform a method comprising:
replicating the virtual machine to produce a replica;
applying a software update to the replica that is scheduled to be made to the virtual machine, without applying the software update to the virtual machine at the same time, before the software update is applied to the virtual machine;
in parallel with the applying, updating a state of one of the virtual machine and the replica so that a state of the virtual machine matches a state of the replica, wherein the updating comprises:
testing the replica after the applying;
saving user requests received by the virtual machine during the replicating and the applying into a queue, wherein the virtual machine continues to process the user requests during the replicating and the applying;
creating a mapping between those of the user requests that travel from a virtual machine of the plurality of virtual machines under a control of a first party to a virtual machine of the plurality of virtual machines under a control of a second party and corresponding responses to those of the user requests from the virtual machine of the plurality of virtual machines under the control of the second party to the virtual machine of the plurality of virtual machines under control of the first party;
replaying data flows between the virtual machine of the plurality of virtual machines under the control of the first party and the virtual machine of the plurality of virtual machines under the control of the second party in the replica, in accordance with the mapping;
replaying the user requests from the queue to the replica after the applying, until the queue is empty;
delivering new user requests received after the replaying to the virtual machine and to the replica until a predefined maintenance window arrives;
switching execution of the application from the virtual machine to the replica when the predefined maintenance window arrives; and
shutting down the virtual machine after the switching.

Assignees

• IBM

Inventors

• Baset Salman A
• Huang Hai
• Singh Manas
• Tak Byung Chul
• Tang Chunqiang
• Wang Long

Classifications

• H04W4/003

  Electricity · mapped topic

• G06F8/65 Primary

  Updates (security arrangements therefor G06F21/57) · CPC title

• H04L67/10

  in which an application is distributed across nodes in the network (software deployment G06F8/60; multiprogramming arrangements G06F9/46) · CPC title

• G06F9/45558

  Hypervisor-specific management and integration aspects · CPC title

• G06F2009/4557

  Distribution of virtual machine instances; Migration and load balancing · CPC title