Geneos - What does the message "data exceeds connection max limit" in gateway log mean?

The connection buffer is used to temporarily store information that will be sent to a particular connection.  In the case of the above message, the numbers 0/0/68129361 indicate that the current read and write buffers are empty (as it should be for a new connection) but the data that we are trying to send on that connection has a size of 68MB (68129361 in above message).
 
Since the connection buffer limit is set at 60MB (62914560 in above message), the connection is aborted. So you may work around this particular issue by increasing the limit for the connection buffer to, say, 100MB (export CONNECTION_BUFFER_MAX=100).

That 68MB represents the initial image of all the dataview data that is sent up to an AC when it first connects. So it's simply about the size of the dataviews (the number of rows and columns).

Some recommendations: 
1. Examine the gateway configuration and dataview sizes.
2. In the gateway startup script, increase the buffer size.
3. Split the gateway if necessary.