HLClock v0.1.3 HLClock View Source
Hybrid Logical Clock
Provides globally-unique, monotonic timestamps. Timestamps are bounded by the clock synchronization constraint, max_drift.
Implementation assumes that timestamps are (at a minimum) regularly sent; a clock at rest will eventually be unable to generate timestamps due to assumed bounds on the logical clock relative to physical time.
In order to account for physical time drift within the system, timestamps should regularly be exchanged between nodes. Generate a timestamp at one node via HLClock.send_timestamp/1; at the other node, call HLClock.recv_timestamp/2 with the received timestamp from the first node.
Inspired by https://www.cse.buffalo.edu/tech-reports/2014-04.pdf
Link to this section Summary
Functions
Determines if the clock’s timestamp “happened before” a different timestamp
Configurable clock synchronization parameter, ε. Defaults to 300 seconds
Functionally equivalent to using send_timestamp. This generates a timestamp for local causality tracking
Given the current timestamp for this node and a provided remote timestamp, perform the merge of both logical time and logical counters. Returns the new current timestamp for the local node
Generate a single HLC Timestamp for sending to other nodes or local causality tracking
Link to this section Functions
Determines if the clock’s timestamp “happened before” a different timestamp
Configurable clock synchronization parameter, ε. Defaults to 300 seconds
Functionally equivalent to using send_timestamp. This generates a timestamp for local causality tracking.
Given the current timestamp for this node and a provided remote timestamp, perform the merge of both logical time and logical counters. Returns the new current timestamp for the local node
Generate a single HLC Timestamp for sending to other nodes or local causality tracking