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log4rs

docs crates.io License: MIT OR Apache-2.0 CI Minimum rustc version

log4rs is a highly configurable logging framework modeled after Java's Logback and log4j libraries.

Quick Start

log4rs.yaml:

refresh_rate: 30 seconds
appenders:
  stdout:
    kind: console
  requests:
    kind: file
    path: "log/requests.log"
    encoder:
      pattern: "{d} - {m}{n}"
root:
  level: warn
  appenders:
    - stdout
loggers:
  app::backend::db:
    level: info
  app::requests:
    level: info
    appenders:
      - requests
    additive: false

lib.rs:

use log::{error, info, warn};
use log4rs;

fn main() {
    log4rs::init_file("config/log4rs.yaml", Default::default()).unwrap();

    info!("booting up");

    // ...
}

Rust Version Requirements

1.69

Building for Dev

Compression

If you are using the file rotation in your configuration there is a known substantial performance issue with the gzip feature. When rolling files it will zip log archives automatically. This is a problem when the log archives are large as the zip happens in the main thread and will halt the process while the zip is completed.

The methods to mitigate this are as follows.

  1. Use the background_rotation feature which spawns an os thread to do the compression.
  2. Do not enable the gzip feature.
  3. Ensure the archives are small enough that the compression time is acceptable.

For more information see the PR that added background_rotation.

License

Licensed under either of

at your option.

Contribution

Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in the work by you shall be dual licensed as above, without any additional terms or conditions.