The iFormBuilder database architecture is set up in a cluster configuration.
This results in the "ID" of records for each form incrementing in steps. Normally you should notice values increasing by 3's as there are currently 3 different servers the records are written too. (Ex. 1, 4, 7, 10).
If for any reason one of the servers maintaining the Master Node 1 would fail, (hardware fails all the time) there are two other servers running to that can step into the Master 1 Node's role. When one of the servers fail, and only two machines are running then IDs may increment in 2's (Ex. 10, 12, 24) and will remain that way until the server that failed comes back online.
Most of the time you should see a consistent flow and ID sequence will follow the pattern of 3's. As we as a company grow, you may see the numbers begin to increase by a greater number.
iFORM TIP: If there is a change in the increment, that is a good indication one of the servers had a problem and you may want to review records submitted during that timeframe for consistency.