Unique ID Generator diagram template
Time-ordered 64-bit identifiers from many generators without central coordination.
About this design
Auto-increment columns stop working the moment data spans several databases, and a single ticket server becomes a bottleneck and a single point of failure. The Snowflake style answer packs a timestamp, a machine identifier and a per-millisecond sequence into 64 bits, so every generator can mint ids independently and they still sort roughly by time. The only coordination happens at start up, when a node claims a unique machine id from a small coordination store. Services call the generator through a library or a thin service, and clock drift is guarded by refusing to issue ids if time moves backwards. Use this template to discuss bit allocation, what happens on a leap second or a restart inside the same millisecond, why ULIDs and UUIDs trade ordering for simplicity, and how ids interact with database index locality.
Diagram as text
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title "Unique ID generator"
direction LR
service orders "Order service" -> service idgen "ID generator"
[idgen x3]
service users "User service" -> idgen
idgen -> db postgres "Machine id registry"
monitor prometheus "Clock drift alerts"
idgen -> clock-drift-alerts
