---
layout: docs
page_title: rpc Block in Agent Configuration
description: >-
   Configure Nomad's RPC behavior in the `rpc` block of a Nomad agent configuration. Modify RPC session configuration, change stream accept backlog, keepalive interval, and open stream timeouts.
---

# rpc Block in Agent Configuration

<Placement groups={['rpc']} />

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.

```hcl
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.