Definition

Freshness and ETA

Nothing emits an event for the file that did not arrive.

freshness = now - max (event time in the dataset), ETA = \frac{remaining work}{observed rate}

Where it appears

Each mechanism states it in its own names. The general symbol each name stands for is shown with it.

Observability & Operations
What is the smallest description of a running system from which we can find a fault, fast enough to matter, at a cost we can still pay while the system is failing?
$now - max (event_time)$
Read it in place →
Observability & Operations
What is the smallest description of a running system from which we can find a fault, fast enough to matter, at a cost we can still pay while the system is failing?
$remaining work \div observed rate$
Read it in place →