Existing MySQL naming convention makes two separate tables for each interface monitored. Table names are flows4_<ifid> and flows6_<ifid>. Ifid is a unique integer identifier chosen by ntopng.
Present commit simplifies this structure and make just two tables, namely flows4 and flows6, and add an extra column to store the interface names. I do not think that storing the integer interface id is good: it is just a number that only make sense inside ntopng. Using interface names would yield more (re)usable data.
Committed code transparently migrates old tables into the new ones. Old flows are migrated into the new tables, and old tables are dropped.
ntopng instance name can be specified using command line parameter
--instance-name. If no parameter is specified, instance name defaults
to the current host name.
this information is exported to MySQL and ES.
