Novell EDIRECTORY 8.8 SP3, Administration Manual, Page: 555 / 634

Maintaining Novell eDirectory 555
n
ov
do
cx (e
n)
11
Ju
ly 20
08
18.4.3 Deploying ARC
ARC is usually deployed on a server-to-server basis. Those servers that are ARC - enabled can know
the new costing information.
You should patch all the servers to 8.7.3.9 ftf3 and eDirectory 8.8 servers to 8.8.2 version and then
enable ARC on each server in the environment.
Deployment Considerations
It is not useful to enable ARC on all servers. Figure 18-4 shows a situation that could impact the
efficiency of LDAP servers. In the figure, S4 holds a copy of the green partition, but not of the blue
partition. Any chaining LDAP request that requires information from the blue partition needs to
walk to the S1, S2, or S3 servers to be fulfilled. This works in most cases, and ARC is designed for
just such situations.
Figure 18-4
ARC Deployment Considerations
However, performing specific LDAP operations could be difficult. Although it is possible to add a
user, for example, Bob.Blue.Novell, the operation might fail when you try to immediately return to
modify Bob. The figure shows Bob added on S2, but modifying Bob on S3 has failed because S3 has
not yet synchronized with S2, so S3 has not yet received Bob. ARC has the capability to direct you
to a different server, because ARC is more dynamic than the original costing method.
This configuration works well in scenarios where the server costs don't vary much and they don't
have problems synchronizing. Disabling ARC on S4 resolves this issue.