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Consul
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Consul RTT

Command: consul rtt

Corresponding HTTP API Endpoints: [GET] /v1/coordinate/datacenters, [GET] /v1/coordinate/nodes

The rtt command estimates the network round trip time between two nodes using Consul's network coordinate model of the cluster.

See the Network Coordinates internals guide for more information on how these coordinates are computed.

The table below shows this command's required ACLs. Configuration of blocking queries and agent caching are not supported from commands, but may be from the corresponding HTTP endpoint.

ACL Required
node:read1

1 When referencing WAN coordinates, no ACL permission is needed.

Usage

Usage: consul rtt [options] node1 [node2]

At least one node name is required. If the second node name isn't given, it is set to the agent's node name. These are the node names as known to Consul as the consul members command would show, not IP addresses.

Sample Output

If coordinates are available, the command will print the estimated round trip time between the given nodes:

$ consul rtt n1 n2
Estimated n1 <-> n2 rtt: 0.610 ms (using LAN coordinates)

$ consul rtt n2 # Running from n1
Estimated n1 <-> n2 rtt: 0.610 ms (using LAN coordinates)

$ consul rtt -wan n1.dc1 n2.dc2
Estimated n1.dc1 <-> n2.dc2 rtt: 1.275 ms (using WAN coordinates)

Command Options

  • -wan - Instructs the command to use WAN coordinates instead of LAN coordinates. By default, the two nodes are assumed to be nodes in the local datacenter and the LAN coordinates are used. If the -wan option is given, then the WAN coordinates are used, and the node names must be suffixed by a period and the datacenter (eg. "myserver.dc1"). It is not possible to measure between LAN coordinates and WAN coordinates, so both nodes must be in the same area.

The following environment variables control accessing the HTTP server via SSL:

API Options

  • -ca-file=<value> - Path to a CA file to use for TLS when communicating with Consul. This can also be specified via the CONSUL_CACERT environment variable.

  • -ca-path=<value> - Path to a directory of CA certificates to use for TLS when communicating with Consul. This can also be specified via the CONSUL_CAPATH environment variable.

  • -client-cert=<value> - Path to a client cert file to use for TLS when verify_incoming is enabled. This can also be specified via the CONSUL_CLIENT_CERT environment variable.

  • -client-key=<value> - Path to a client key file to use for TLS when verify_incoming is enabled. This can also be specified via the CONSUL_CLIENT_KEY environment variable.

  • -http-addr=<addr> - Address of the Consul agent with the port. This can be an IP address or DNS address, but it must include the port. This can also be specified via the CONSUL_HTTP_ADDR environment variable. In Consul 0.8 and later, the default value is http://127.0.0.1:8500, and https can optionally be used instead. The scheme can also be set to HTTPS by setting the environment variable CONSUL_HTTP_SSL=true. This may be a unix domain socket using unix:///path/to/socket if the agent is configured to listen that way.

  • -tls-server-name=<value> - The server name to use as the SNI host when connecting via TLS. This can also be specified via the CONSUL_TLS_SERVER_NAME environment variable.

  • -token=<value> - ACL token to use in the request. This can also be specified via the CONSUL_HTTP_TOKEN environment variable. If unspecified, the query will default to the token of the Consul agent at the HTTP address.

  • -token-file=<value> - File containing the ACL token to use in the request instead of one specified via the -token argument or CONSUL_HTTP_TOKEN environment variable. This can also be specified via the CONSUL_HTTP_TOKEN_FILE environment variable.

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