rpc Block in Agent Configuration

This page provides reference information for configuring Nomad's RPC behavior in the rpc block of a Nomad agent configuration. Modify RPC session configuration, stream accept backlog, keepalive interval, and open stream timeouts. We strongly recommend leaving these values unconfigured to use the default values, which have been production-proven on clusters of thousands of nodes. You should only configure the rpc block if you have specific reason to believe it will improve your specific use case.

rpc {
  accept_backlog           = 256
  keep_alive_interval      = "30s"
  connection_write_timeout = "10s"
  max_stream_window_size   = 262144
  stream_open_timeout      = "75s"
  stream_close_timeout     = "5m"
}

rpc Parameters

• accept_backlog (int: 256) - Limits how many RPC streams (requests) can be waiting for acceptance by the RPC server.

• keep_alive_interval (string: 30s) - How often to perform the keep alive

• connection_write_timeout (string: 10s) - Safety valve timeout after which you should suspect a problem with the underlying connection and close it. This is only applied to writes, where there is generally an expectation that things move along quickly.

• max_stream_window_size (int: 262144) - Controls the maximum window size allowed for a stream, in bytes.

• stream_open_timeout (string: 75s) - Maximum amount of time that a stream remains in pending state while waiting for an ACK from the peer. Once the timeout is reached, Nomad gracefully closes the session. A zero value disables the stream open timeout, allowing unbounded blocking on open stream calls.

• stream_close_timeout (string: 5m) - When close is called, maximum time that a stream is in a half-closed state before forcibly closing the connection. Forcibly closed connections empty the receive buffer, drop any future packets received for that stream, and send an RST to the remote side.