So looking at the database traffic I was being hit with a lot of traffic from one of the webservers. I checked into the the scheduler and noticed that the broadcastpollingprovider scheduler was running every 30 seconds. The slow response was due to having to wait 1 minute + to get a database connection.

I turned off that scheduled job and now my site loads the same for both servers. However, I am still noticing very large growth of the Broadcasts and Servers table. My database size has gone from 94MB to 70GB! Is there any documentation on what these tables do? At a glance, they look like session logging Is there a clean up process or configuration I have missed?

(I have since figured out the problem, you will need to have the broadcastpollingprovider turned on. See post below for the rest of the solution.)

After this last post, I noticed that I still had a problem with a growing Broadcasts table. I was up to 1,000,000 + records in just a matter of days. What I noticed was that the following SQL statement was supposed to be purging the broadcasts table every time the broadcastpollingprovider was scheduled to run (30 seconds by default):

 DELETE FROM {databaseOwner}{objectQualifier}Broadcasts
 WHERE BroadcastDate < (SELECT Min(LastPollDate) FROM {databaseOwner}{objectQualifier}Servers WHERE ServerID<>{databaseOwner}{objectQualifier}Broadcasts.SourceServerID)

Found in  DNNINSTALLROOT\Library\Providers\CachingProviders\BroadcastPollingCachingProvider\Install\Install.SQLDataProvider

I checked my minimum poll date of my servers table and it was several days ago. Turns out, I had an entry in the servers table from my staging server. I had not used the staging environment for several days (13 to be exact). What I found is that since I was not using the staging server, the poll date was not being updated. I deleted the staging server's entry in the servers table (ensuring no orphaned records in the cachedobjects and broadcasts table). I immediately went from 1,000,000 + records to around 70. I now have only my two production servers listed in the servers table. My Broadcasts table averages 200-300 rows. It is now under control.

So, the moral of the story is....

•  Make sure that you only have your active production servers listed in the Servers table and nothing else.
• DotNetNuke.Services.Cache.PurgeCache is not necessary for the BroadcastPollingProvider implementation of the WebFarm.