---
layout: docs
page_title: Server Configuration
description: Boundary configuration reference.
---

# Configuration

[listener]: /docs/configuration/listener
[telemetry]: /docs/configuration/telemetry
[controller]: /docs/configuration/controller
[worker]: /docs/configuration/worker
[kms]: /docs/configuration/kms

Outside of development mode, Boundary controllers and workers are configured using a file.
The format of this file is [HCL](https://github.com/hashicorp/hcl). In this section you'll find
configuration block examples for Boundary controllers and workers.

After the configuration is written, use the `-config` flag to specify a local path to the file.

## Parameters

- [`controller`](/docs/configuration/controller): Controller specific
  configuration. If present, `boundary server` will start a Controller subprocess.

- [`worker`](/docs/configuration/worker): Worker specific configuration. If
  present, `boundary server` will start a Worker subprocess.

- [`listener`](/docs/configuration/listener): Configures the listeners on which
  Boundary serves traffic (API, cluster, and proxy).

  Controllers will have two listener blocks: one marked for `api` purpose and
  the other marked for `cluster` purpose. By default, the API listener runs on
  :9200 and the cluster listener (currently used for worker communication) uses
  :9201.

  Workers will have only one listener, marked for `proxy` purpose.

- [`kms`](/docs/configuration/kms): Configures KMS blocks [for various
  purposes](/docs/concepts/security/data-encryption).

- `disable_mlock` `(bool: false)` – Disables the server from executing the
  `mlock` syscall, which prevents memory from being swapped to disk. This is
  fine for local development and testing; in production, it is not recommended
  unless the systems running Boundary only use encrypted swap or do not use swap
  at all. Boundary only supports memory locking on UNIX-like systems that
  support the mlock() syscall (Linux, FreeBSD, etc).

  On Linux, to give the Boundary executable the ability to use the `mlock`
  syscall without running the process as root, run:

  ```shell
  sudo setcap cap_ipc_lock=+ep $(readlink -f $(which boundary))
  ```

  If you use a Linux distribution with a modern version of systemd, you can add
  the following directive to the "[Service]" configuration section:

  ```ini
  LimitMEMLOCK=infinity
  ```

- `log_level` `(string: "info")` – Specifies the log level to use; overridden by
  CLI and env var parameters. Supported log levels: Trace, Debug, Error, Warn, Info.

- `log_format` `(string: "")` – Specifies the log format to use; overridden by
  CLI and env var parameters. Supported log formats: `"standard"`, `"json"`.

## Example Configurations

For complete example configurations see the sections for [controller](/docs/configuration/controller) and [worker](/docs/configuration/worker).