--- layout: "simulator" page_title: "Convergence Simulator" sidebar_current: "docs-internals-simulator" ---

Serf Convergence Simulator

The graph below shows the expected time to reach various states of convergence depending on the settings which are tunable below the graph. Below the graph, the estimated maximum bandwidth usage is shown per node in kilobits per second.

The default values in the boxes are also the default values that Serf is configured with, where applicable.

Estimated max bandwidth: 0 kbps/node

Gossip Interval

The gossip interval controls how often messages are gossiped to other nodes

seconds
Gossip Fanout

The gossip fanout controls how many nodes we gossip with

nodes
Nodes

This controls how many simulated nodes are in the cluster

Packet Loss

This controls the amount of simulated packet loss [0, 100)

% lost packets
Node failures

This controls what percent of simulated nodes are failed

% failed