Orders are not creating in Sequence when we use Oracle RAC and getting skipped to 1000000 in OSM 7.2
See OSM 7.2 release notes.
Order ID Generation
OSM 7.2 uses a new order ID generation mechanism. Each database server instance allocates order IDs in blocks. The instance then provides an order ID to each newly created order from the block, When all order IDs from the block are used, a new block is allocated. The overhead normally incurred by each instance to allocate sequence numbers such as the order ID one at a time and synchronize with other instances is avoided.