Table 6-1 Effects of replication and remote lookup on the network

Load type

Objects1

Accesses/day2

Avg. entry size

Load

Replication

1 million

100,000

1Kb

100Mb/day

 

 

 

 

 

Remote Lookup

100

1,000

1Kb

1Mb/day

 

 

 

 

 

1For replication, objects refers to the number of entries in the database. For remote lookup, it refers to the number of users who access the database.

2For replication, Accesses/day is based on a 10% change rate to the database that needs to be replicated. For remote lookup, it is based on ten lookups per day for each remote user.

Given the difference in loads caused by replication versus that caused by normal directory usage, using replication for network load-balancing purposes may not be desirable. On the other hand, the benefits of locally available directory data can far outweigh any considerations regarding network loads.

A good compromise between making data available to local sites and overloading the network is to use scheduled replication. For more information on data consistency and replication schedules, see “Data consistency”.

6.3.8.1 Example of network load balancing

In this example, the enterprise has offices in New York and Los Angeles, and each office has specific subtrees that they manage.

Figure 6-9 Managing enterprise subtrees in remote offices

Each office contains a high-speed network, but the connecion between two cities is unreliable. To balance the network load:

1.Select one server in each office to be the supplier server for the locally managed data.

2.Replicate locally managed data from that server to the corresponding supplier server in the remote office.

3.Replicate the directory tree on each supplier server (including data supplied from the remote office) to at least one local Directory Server to ensure availability of the directory data. Use multi-master replication for the suffix that is managed locally, and cascading replication for the suffix that receives a master copy of the data from a remote server.

6.3 Defining a replication strategy

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