We have built a Drupal application that is going to be Load Balanced over multiple servers.
The hosting company have asked us what kind of session based persistency is required on their Cisco load balancer. The options are:
the definition of these is:
1) IP-Netmask: In this case, the source IP address, the destination IP address, or both are used to uniquely identify individual clients and their requests for persistency purposes based on their IP netmask.
2) Cookie-Active: Client cookies uniquely identify clients to the load-balancer and to the servers that provide content. A cookie is a small data structure within the HTTP header that is used by a server to deliver data to a web client and request that the client store the information. In certain applications, the client returns the information to the server to maintain the connection state or persistence between the client and the server. COOKIE-ACTIVE therefore is when the load-balancer inserts the cookie on behalf of the server when a reply is being sent back to a client’s request, this way; the load-balancer carries out persistence so that it can identify a connection from a specific server to a specific client
3) Cookie-Passive: The load-balancer learns or reads the cookies that the web server inserts in the HTTP header to identify the connection when responding to a client’s request.
Question: Which one should we use and why?