How are replicated packages distributed, and what limitations are there?
Altiris Agents are never permitted to download packages across a hierarchy, they will always wait and download from local Package Servers
Only Package Servers in the same Site as the NS are permitted to download packages across the hierarchy
The user controls which Package Servers in the NS site they do not want to download across the hierarchy by setting these Package Servers to 'Constrained'. As Constrained Package Servers are not permitted to download packages outside their hierarchy location
In relation to the above point, there is also an NS core setting called 'PackageRequestBlockoutSeconds'. Below is an explanation of how this setting works.
When a Package Server contained in the NS site requests a replicated package it is marked as the only Package Server that can make a request across the hierarchy for that package for the next 10 minutes.
All other Package Servers who make a request to go across the hierarchy for this package during the 10 minute window will be returned a backoff message.
After the 10 minute window has expired, the next Package Server within the NS site to request the package will be given the 10 minute window, and so on, until the package is downloaded successfully by one Package Server.
The package request blockout time is set 10 minutes by default, but is configurable through the Core setting 'PackageRequestBlockoutSeconds'
The blockout period is assigned per package.
Package Server assignment of replicated Packages -
When a Package is replicated it will change the Package Server assignment method on import of the package at the destination, depending on which assignment method it was previously, see below for these changes -
- Package Servers by Site > Changes to > Package Servers automatically with manual pre-staging
- Package Servers automatically with manual pre-staging > Stays as > Package Servers automatically with manual pre-staging
- All Package Servers > Stays as > All Package Servers
- Package Servers individually > Changes to > Package Servers automatically with manual pre-staging
At the destination NS when the Package is imported, it automatically assigns the Package to the NS Site, i.e. to the Package Servers in the child NS Site.
This was one of things we did to ensure that distribution of the replicated package within the child site would be carried out regardless of other factors, like a SWD task being rolled out to clients inside the child NS site.
Other KBs to check:
HOWTO9693 - When replicating a package, what exactly is replicated?
HOWTO9694 - How does a replicated package get distributed to child Package Servers?