Data Center

The JDC should be established in an industrial strength data center that can guarantee 99.9% uptime.  It is advisable to use a monitoring service to ping the JDC regularly and have support staff in the data center ready to take immediate action in the event of a server crash or other interruption.  ClickTracks uses www.datapipe.com for the JDC that handles its hosted service.  Another excellent hosting provider is www.rackspace.com.

Of course, many larger corporations run their own data centers with enough support to run the JDC reliably.  Each company must decide where to place the JDC, bearing in mind that each second of downtime can result in significant lost data.

One solution that is definitely not advisable is a Virtual Private Server (VPS). VPS installs are not supported because a high volume site will cause many requests to be made to the JDC, and this peak traffic pattern causes other VPS installs on the same box to have problems.

Load Balancing

JDC's can be tied together in a cluster for unlimited scalability.  The JDC supports either Virtual IP load balancing or DNS Round Robin.  In either case, the load balancing mechanism is set up separately from the JDC itself.  If it is a virtual IP load balancing setup, it will probably be set up on a network router.  In the case of a DNS Round Robin load balancer, it will be set up on the DNS server.  
 

The details of setting up a load balancer vary from device-to-device and software-to-software, so it will not be covered in this document.  Ultimately, the load balancer needs to distribute requests among the various JDC boxes set up in the system. (See Data Collection Servers).