ReferenceGlossary
Token bucket
A rate limiting algorithm. A bucket holds up to B tokens and refills at a fixed rate r; each request takes a token, and a request that finds the bucket empty waits or is rejected. It allows short bursts of up to B while it holds the long-run average to r.
Performance
In Quorum#
Burstable instances run on a token bucket of CPU credits. A Burstable Node earns credits while it uses less than 20% of its vCPU, banks up to 100 core-seconds per vCPU, and spends them to run above that baseline. When the bucket is empty it drops to 20% CPU, so a Burstable box that runs hot all day stalls; in exchange it costs 0.4 times a General box.