Original source: http://flakeidgenerators.codeplex.com/

Flake ID Generators is a set of decentralized, k-ordered id generation services in C#.

• FlakeGen.Id64Generator - generates 64-bit ids. The implementation is heavily derivative of Twitter's Snowflake written is Scala.
• FlakeGen.IdGuidGenerator - generated Guid (128-bit) ids
• FlakeGen.IdStringGeneratorWrapper - a wrapper for FlakeGen.Id64Generator returning k-ordered ids in various string formats (e.g. number, hex, base 32)

Both services generates k-ordered ids (read time-ordered lexically). Run one on each node in your infrastructure and they will generate conflict-free ids on-demand without coordination.

• Generator written in C#
• Compact ids (under 64 bit) directly sortable
• Id is composed of:
  • time - 41 bits (millisecond precision)
  • configured instance id - 10 bits - gives us up to 1024 instances
  • sequence number - 12 bits - usually 0, incremented when more than one id is requested in the same millisecond and reset to 0 when the clock ticks forward. Rolls over every 4096 per machine.
    • The generator has protection mechanism for sequence roll over in the same millisecond.

• Generator written in C#
• Generated ids directly sortable
• Id is composed of:
  • time - 64-bits - milliseconds since the epoch (Jan 1 1970)
  • configured instance id - 48 bits - it can be MAC address from a configurable device or database sequence number or any other 6 bytes identifier
  • sequence number - 16-bits - usually 0, incremented when more than one id is requested in the same millisecond and reset to 0 when the clock ticks forward. Rolls over every 65536 per machine.