Symbol P_slow
the probability that at least one of p participants does so.
Read this term in its guide →Published equation contexts
The reason this matters more for collectives than for ordinary traffic is synchronisation. A collective is a barrier. Every participant waits for the operation to complete, so the operation completes when the last contribution arrives. Tail latency therefore stops being a tail statistic and becomes the mean cost of every step. Dean and Barroso’s analysis of latency variability in large fan-out services is the canonical statement of the mechanism: background activity, queueing at multiple layers including network switches, and shared-resource contention produce occasional slow responses, and a request that must wait on many servers is very likely to encounter one [ 18 ] . The arithmetic is…
the probability that at least one of p participants does so.
Read this term in its guide →p is one of the signed contributions combined to compute the quantity on the left.
Read this term in its guide →Read it with the definitions, units, and assumptions supplied by the article.
A symbol can carry a different meaning in another article. Each occurrence keeps its own guide and term definitions.
Equation 30 · AI Hardware & Semiconductors
This equation states an equality: the expressions on both sides have the same value under the article’s assumptions.
The reason this matters more for collectives than for ordinary traffic is synchronisation. A collective is a barrier. Every participant waits for the operation to complete, so the operation completes when the last contribution arrives. Tail latency therefore stops being a tail statistic and becomes the mean cost of every step. Dean and Barroso’s analysis of latency variability in large fan-out services is the canonical statement of the mechanism: background activity, queueing at multiple layers including network switches, and shared-resource contention produce occasional slow responses, and a request that must wait on many servers is very likely to encounter one [ 18 ] . The arithmetic is…