Introduction to Persistence Profiles at an MCP 2.0 Data Center

Content / Solution:

Persistence Profiles are a component within MCP 2.0 VIPs. For details please refer to Introduction to Virtual Listeners / VIPs in MCP 2.0

In general terms, Persistence Profiles determine how a load-balancer ties a specific user session to a ‘back end’ computing resource.  This session affinity may be needed because a web or app server in a load-balanced configuration holds session-specific information about the end user, or because that server has specific database records; open/locked, etc.  If SSL Offloading is not being performed, then the SSL tunnel between the client and the server must be maintained.  The load-balancer can use a number of variables to determine how to tie a user session.  A cookie can be inserted into the session that the load-balancer tracks, source or destination IP address, ssl session ID, a calculated hash, SIP info, and MSRDP data can all be used to establish session persistence.  Only Source/Destination Address, Cookie and SIP Header options area available at this time. 

In the context of MCP 2.0, Persistence Profiles can be specified as part of Virtual Listener creation and management. Please refer to:

• How to Create a Virtual Listener on a Network Domain
• How to Manage Virtual Listeners on a Network Domain 

A Persistence Profile provides a method for ensuring that traffic from a client is sent to the same server in a pool based on a attribute of the connection.

A Fallback Persistence Profile is used when the primary persistence profile fails. For example; if cookie persistence is used, but traffic arrives without a cookie, the fallback persistence profile will be used as a last resort.

Default Persistence Profiles:

• CCDEFAULT.SourceAddress - Matches a connection solely based on source IP address.
• CCDEFAULT.Cookie -  Inserts an HTTP cookie into HTTP traffic that identifies the target pool member.
• CCDEFAULT.DestinationAddress - Matches a connection solely based on destination IP address.
• CCDEFAULT.Sip - Matches a connection solely based on information in the SIP header.
• The set of profiles which is compatible for a given Virtual Listener is determined by the combination of the Type and Protocol of the Virtual Listener. Initially compatibility is as follows:

Note for API integrators that the List Default Persistence Profiles function described in the API documentation includes compatibility information for programmatic use. The information details the appropriate combinations of Persistence Profiles and Fallback Persistence Profiles in conjunction with the Type and Protocol of a given Virtual Listener. Note that the set of Persistence Profiles is subject to change over time.