Replication Resource Requirements; Fractional Replication - Red Hat DIRECTORY SERVER 7.1 - DEPLOYMENT Deployment Manual

• The number and size of the entries stored in the directory.
A site that manages human resource databases or financial information is
likely to put a heavier load on your directory than a site containing engineering
staff that uses the directory for simple telephone book purposes.

Replication Resource Requirements

Using replication requires more resources. Consider the following resource
requirements when defining your replication strategy:
• Disk usage — On supplier servers, the changelog is written after each update
operation. Supplier servers receiving many update operations may see higher
disk usage.
In addition, as there is a single changelog on every supplier server. If a supplier
contains multiple replicated databases, the changelog will be used more
frequently, and the disk usage will be even higher.
• Server threads — Each replication agreement consumes one server thread. So,
the number of threads available to client applications is reduced, possibly
affecting the server performance for the client applications.
• File descriptors — The number of file descriptors available to the server is
reduced by the changelog (one file descriptor) and each replication agreement
(one file descriptor per agreement).

Fractional Replication

Fractional replication allows the administrator to choose a set of attributes that will
not be transmitted from a supplier to the consumer. This means administrators can
replicate a database without replicating all the information in it.
Fractional replication is enabled and configured per replication agreement. The
exclusion of attributes is applied equally to all entries. As far as the consumer
server is concerned, the excluded attributes always have no value. Therefore, a
client performing a search against the consumer server will never see the excluded
attributes returned. Similarly, should it perform a search that specifies those
attributes in its filter, no entries will match.
Fractional replication is particularly useful in these situations:
Defining a Replication Strategy
Chapter 6 Designing the Replication Process 127