Administration Guide › Set Up Distribution and Routing › Horizontal Partitioning › Specify Horizontal Partitioning

Specify Horizontal Partitioning

Specify horizontal partitioning to partition a namespace amongst DSAs.

To specify horizontal partitioning

1. Select the attribute whose value you will use to partition the namespace.
2. Select a hash algorithm

   You can choose hash1 or hash2.

3. For each DSA in the partitioning, append to the prefix the string that determines the partition hashing.

   You specify the prefix in the knowledge, so use either DXmanager or the set dsa command (prefix parameter).

4. Ensure each data DSA has disable-client-binds set to true.

   This forces requests to the DSAs to go through the router.

Example: Configuration for Horizontal Partition

The configuration of the DSAs is set up as follows:

• The router has prefix: <c AU> <ou Users>
• DSA_A has prefix: <c AU> <ou Users> <guid "[hash1(3)=0]" >
• DSA_B has prefix: <c AU> <ou Users> <guid "[hash1(3)=1]" >
• DSA_C has prefix: <c AU> <ou Users> <guid "[hash1(3)=2]" >

From a client point of view all entries appear in the namespace <c Au> <ou Users>.

When the router receives a request, the router applies the specified hash function (hash1) to the specified attribute value (guid) in the request. If the result is zero, it routes the request to DSA_A. If the result is one, it routes the request to DSA_B, and so on.