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Delta Diff Discovery for AD or ADAM, special considerations
Category:General
Last Updated:2011-08-11
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The command line Delta Diff Discovery solution allows for a faster Discovery run by only pulling 'changes' from the source directory. The Diff pull produces a DIFF file containing records for source objects that have been Added, Modified or Deleted since the last Diff run. While this produces a much faster result, there are caveats to this feature that are worth considering before implementing the new solution.
- Diffs must consistently be run from the same source DC. On a normal Discovery, changing the source IP is supported since a complete Discovery pulls all records. A Diff pulls only chages, based on the USNChanged value, which is unique for every DC. Changing the IP will result in data that is out of sync. Once the Delta Diff Discovery process is run, the sync tracks the objects using the USN from the GC. The Delta Diff Discovery Source IP should not be changed.
- Order processing is very important. Lost or out of order processing will result in data that is out of sync.
- The ldap query which pulls objects on Diff will miss objects that no longer fall within the scope of the sync. For example, objects moved on the source, changes to Selection DN, or changes made to ldap filters may not have the desired effect, possibly leaving orphaned objects on the destination instead of deleting them.