Nondeterministic value source

摘要

A technology is described for providing a nondeterministic value to computing instances executing an application as part of a high availability system. An example method may include receiving a request for a nondeterministic value at a physical host that hosts a first computing instance, where the request may be for an application executing on the first computing instance. A nondeterministic value may be obtained from a nondeterministic value source located on the physical host and provided to the application executing on the first computing instance. A second request from a second computing instance may be received at the physical host, where the second request may be associated with a copy of the application executing on the second computing instance. The nondeterministic value may then be identified in the computer memory of the physical host and provided to the second computing instance over a computer network.

主权项

1. A non-transitory machine readable storage medium having instructions embodied thereon, the instructions when executed by a processor:
receive a request for a nondeterministic value from a first computing instance executing an application on a first physical host, and the first computing instance is configured to obtain the nondeterministic value from a nondeterministic data source; provide the nondeterministic value to the first computing instance; receive a request for the nondeterministic value from a second computing instance executing a copy of the application on a second physical host, and the first computing instance and the second computing instance are configured as a redundant pair; identify the nondeterministic value provided to the first computing instance, in response to the request from the second computing instance, and the second computing instance is configured to obtain the nondeterministic value from the nondeterministic data source; and provide a duplicate of the nondeterministic value to the second computing instance in order to provide an execution state of the copy of the application executing on the second computing instance that duplicates the execution state of the application executing on the first computing instance.