How to implement ODBC LoadBalancing for User Store

Document ID : KB000016656
Last Modified Date : 14/02/2018
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Question:

I'd like to get help to implement ODBC LoadBalancing for User Store. Could you guide me through the changes on system_odbc.ini?

Answer:

  In the system_odbc.ini datadirect file, "LoadBalancing" is actually doing failover. To get it work, you need the following attributes configured :

 

  HostName 

  PortNumber 

  AlternateServers 

  LoadBalancing 

 

  The difference between 0 and 1 for LoadBalancing is the way the driver will pick up the next server from the AlternateServers list : 0 = sequential, 1 = random 

 

  Here's a configuration sample : 

 

  [SiteMinder Oracle Data Source] 

  Driver=/opt/CA/siteminder/odbc/lib/NSora23.so 

  Description=DataDirect 5.3 Oracle Wire Protocol 

  HostName=data1.training.com 

  PortNumber=1521 

  ServiceName=myservice1 

  AlternateServers=(Hostname=data2.training.com:PortNumber=1521:ServiceName=myservice1,Hostname=data3.training.com:PortNumber=1521:ServiceName=myservice1) 

  LoadBalancing=1 

 

 

Additional Information:

Further reading : 

Alternate Servers

 

  Note that the only difference between loadbalancing value 1 and 0 is that when it is set to 0, the driver will pick up the next server in a sequential order instead of randomly (value 1).

 

Progress DataDirect Connect for ODBC Version 7.1.6 

 

  Attribute:   LoadBalancing (LB) 

  Purpose:

  Determines whether the driver uses client load balancing in its attempts to connect to the database servers (primary and alternate). You can specify one or multiple alternate servers by setting the Alternate Servers option. 

  Valid Values:   0 | 1 

  Behavior:

  If set to 1 (Enabled), the driver uses client load balancing and attempts to connect to the database servers (primary and alternate servers) in random order. 

  If set to 0 (Disabled), the driver does not use client load balancing and connects to each server based on their sequential order (primary server first, then, alternate servers in the order they are specified). 

 Default:  0 (Disabled) 

 

Configure an Oracle Policy Store 

  AlternateServers= 

  If the primary server is not accepting connections, specifies the connection failover to the other Oracle nodes. Example:  (HostName=nete_servername2:PortNumber=1521:ServiceName=nete_servicename[,...]) 

  LoadBalancing=1 

  Turns on client load balancing, which helps to distribute new connections to keep RAC nodes from being overwhelmed with connection requests. When enabled, the order in which primary and alternate database servers are accessed is random.