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Anonymous_User Absent Member.
Absent Member.
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Inactive replicas eDir 8.8 Sp8

Hi,

last week, I stumbled over this in TID 3426981
(https://www.netiq.com/support/kb/doc.php?id=3426981):

<cite>
- Inactive replicas need to be excluded from the 6 month difference
check when computing synch window (Bug 827146)
- Inactive replicas should be excluded when calculating the send\receive
max ring deltas (Bug 827145)
</cite>

What is an 'Inactive Replica'?

havent found anything in the documentation on it. Would be really cool,
if there is a new replica type that is simply 'freezed' on one point in
time. Useful for Quick Disaster Recovery functions....



Thorsten
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Anonymous_User Absent Member.
Absent Member.

Re: Inactive replicas eDir 8.8 Sp8

I believe this refers to replicas which previously existed, but are no
more, as in they have been removed from their hosting servers.

To give a little background replication/synchronization happens via
timestamps, and a timestamp has three parts: unsigned integer (seconds
since 1970), a replica number (integer unique to each replica in a
partition's replica ring), and an event ID (1-2^16 or so). As a result it
is possible to uniquely identify every event that goes into eDirectory
from any replica with about 65k possible events causing modifies on each
server each second. When the replica ring merges these changes it finds
out if there are changes by looking at the highest timestamp from each
server and then sending things out to other servers that they do not have.
Each server knows the values of the transitive vectors (attribute on the
partition root object) which holds these numbers.

If you remove a replica from a server (for any reason) the integer in the
timestamps used to identify the replica number is no longer assigned to a
server, but the timestamps stored throughout the tree (until they are
replaced by newer ones, if they ever are replaced by newer ones) are not
going to automatically be updated to remove that same integer. Instead
you can end up with timestamps that refer to a replica number of a replica
that is no longer there... it is now "inactive".

When calculating last update time from a replica that hasn't been around
for hours/days/year, there is no warranted concern about a lack of
activity from an inactive replica, but there is a concern for any other
replica that isn't communicating, which is part of what Report
Synchronization Status or equivalent reports will show.

Good luck.
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