Preview versions of the AMPS server are intended to provide quick access to new features for new development, proof of concept projects, prototyping, or applications that need access to the latest capabilities and improvements in AMPS.
The full "release" (Long Term Support, or LTS) versions are intended to provide an extremely stable version of AMPS for an extended period of time. These versions do not receive new or extended features during the time that they are supported. A fix that would significantly change existing behavior (including, for example, some types of performance improvements) would not typically be applied to a full release.
Preview versions are supported by 60East under the terms and conditions in your support agreement, including support for running preview versions in production.
Preview versions are cumulative. That is, an X.Y.4.0 preview version will contain all of the functionality and fixes in X.Y.3.*, X.Y.2.*, X.Y.1.*, and any applicable hotfixes for the X.Y.0.* release.
However, 60East does not provide extended lifecycle maintenance for preview versions. Since preview releases are not considered full releases of the AMPS server, 60East only provides automatic maintenance and hotfixes for the most recent preview version. That is, hotfixes are automatically produced for X.Y.1.* until X.Y.2.0 ships, then hotfixes are automatically produced for X.Y.2.*. This differs from full releases of AMPS, which are under maintenance for an extended period and receive applicable hotfixes automatically until the end of the support lifetime, regardless of the release of new full releases.
What is the difference between "preview" and "release/LTS"?
These are simply two different development tracks.
Preview versions must pass the same quality, performance, and stability requirements that release/LTS versions must pass before being certified.
The "release/LTS" track emphasizes long-term stability and compatibility. This means that the release track is "feature-frozen" and will not receive additional features or other changes (including performance enhancements) that would significantly change the expected behavior.
By contrast, the "preview" track receives regular updates to features and can include more substantial performance enhancements. When major features are added, 60East increments the preview number (the third position in the version number) to indicate that new capabilities are present. That release is then considered to be the current version of the preview track and hotfixes are applied to the current version. After a series of preview releases, the preview release track will be frozen for new additions and assigned a "release" version number to become the next "release" version.
Can I use a "preview" version in production?
Yes. As noted above, preview versions are supported by 60East under the terms and conditions in your support agreement, including full support for running preview releases in production.
If you choose to run a preview version in production, you may need to move to a more recent preview for hotfixes / performance improvements. As always, 60East maintains a high level of compatibility between AMPS releases, but when moving from one preview release to another, there may sometimes be configuration or other changes needed due to feature additions or fixes. When a "feature-frozen" long term support version containing newer features is released, the application can shift the hotfix strategy to using hotfixes from that release track, or it can continue to track the preview track for additional features and improvements.