Currently melange chooses an ipblock from a network to allocate ips and a mac address range to allocate mac addresses. The block/range to choose is prioritized by their created dates. After the first created block/range is full, it goes to the next one and so on.
In Mysql the datetime field can store time only upto seconds. This can, in rare cases, cause multiple ipblocks or mac ranges to have the same created date. This will in tern mean that the current block/range selected could vary each time.
This would result in multiple ipblocks/ranges being consumed at the same time.
This situation might be undesirable from a ipblock/range management point of view.
The remedy is to have a unique integer counter column in the db for the block and range tables. Prioritizing on this column guarantees that only one block/range is consumed at a particular point of time.
Fix proposed to branch: master
Review: https:/