Network outages cause highly repetitive error reporting in the logs

The error handling does not have any memory. If, for example, a backend DB server loses its connection with MaxScale and the clients continue to attempt connections, the same error is reported repeatedly.

This causes excessive logging which makes log files hard to handle and masks other possible errors.

An example is:

2015-11-03 08:49:54 Error : Couldn't find suitable Master from 2 candidates.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create RW Split Router session because routercould not establish a new router session, see earlier error.
2015-11-03 08:49:54 Error : Couldn't find suitable Master from 2 candidates.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create RW Split Router session because routercould not establish a new router session, see earlier error.
2015-11-03 08:49:54 Error : Couldn't find suitable Master from 2 candidates.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create RW Split Router session because routercould not establish a new router session, see earlier error.
2015-11-03 08:49:54 Error : Failed to create new routing session. Couldn't find eligible candidate server. Freeing allocated resources.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create Read Connection Router session because routercould not establish a new router session, see earlier error.
2015-11-03 08:49:54 Error : Failed to create new routing session. Couldn't find eligible candidate server. Freeing allocated resources.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create Read Connection Router session because routercould not establish a new router session, see earlier error.
2015-11-03 08:49:54 Error : Failed to create new routing session. Couldn't find eligible candidate server. Freeing allocated resources.
2015-11-03 08:49:54 140736837035776 [session_alloc] Error : Failed to create Read Connection Router session because routercould not establish a new router session, see earlier error.

which shows 12 errors being logged in one second, followed by many more in subsequent seconds, until the connection is restored.