Hot Reload

Enable hot reload through SIGHUP signal or an HTTP endpoint

Fluent Bit supports the reloading feature when enabled in the configuration file or on the command line with -Y or --enable-hot-reload option.

Hot reloading is supported on Linux, macOS, and Windows operating systems.

Update the configuration

To get started with reloading over HTTP, enable the HTTP Server in the configuration file:

fluent-bit.conf

[SERVICE]
    HTTP_Server  On
    HTTP_Listen  0.0.0.0
    HTTP_PORT    2020
    Hot_Reload   On
...

fluent-bit.yaml

service:
    http_server: on
    http_listen: 0.0.0.0
    http_port: 2020
    hot_reload: on

How to reload

After updating the configuration, use one of the following methods to perform a hot reload:

HTTP

Use the following HTTP endpoints to perform a hot reload:

• PUT /api/v2/reload

• POST /api/v2/reload

For using curl to reload Fluent Bit, users must specify an empty request body as:

curl -X POST -d '{}' localhost:2020/api/v2/reload

Signal

Hot reloading can be used with SIGHUP.

SIGHUP signal isn't supported on Windows.

Confirm a reload

Use one of the following methods to confirm the reload occurred.

HTTP

Obtain a count of hot reload using the HTTP endpoint:

• GET /api/v2/reload

The endpoint returns hot_reload_count as follows:

{"hot_reload_count":3}

The default value of the counter is 0.