The purpose of this article is to provide an understanding of how VM Migration Software, such as VMware VMotion, works and to answer some of the common questions related to using these softwares with Appian.
Live migration refers to the process of moving a running virtual machine or application between different physical machines without disconnecting the client or application. Memory, storage, and network connectivity of the virtual machine are transferred from the original guest machine to the destination. One commonly used software for this is VMware VMotion.
Appian environments should not be hosted with any live VM migration software enabled because their capability has been known to cause problems with Kafka, a high performance component of Appian, as well as Zookeeper, which is a component it uses. The maintainers of Kafka state here that they recommend disabling VMotion for these components. As stated in our System Requirements documentation, this is a requirement while hosting Appian because these tools may cause data corruption, site unavailability or service degradation. VM migration can often create enough of a communications gap between Appian components that they detect a failure has occurred which can cause internal service metadata to be lost and trigger failover mechanisms.
This article applies to Appian 17.3 and later.
Last Reviewed: March 2021