add_logging.md

◀︎ Airlift • ◀︎ Getting Started • ◀︎ Next Steps

Add Logging

Airlift includes a simple logging API based on the JDK logging package.

Step 1 - Add Needed Dependencies

We need a few additional dependencies. Add the following to the dependencies section of your pom.xml file:

        <dependency>
            <groupId>io.airlift</groupId>
            <artifactId>log</artifactId>
        </dependency>

        <dependency>
            <groupId>io.airlift</groupId>
            <artifactId>log-manager</artifactId>
        </dependency>

Step 2 - Start Logging

Example logging:

import io.airlift.log.Logger;

public class MyClass
{
    private static final Logger LOG = Logger.get(MyClass.class);
    
    public void fooBar(String argument)
    {
        LOG.info("Formatted output %s", argument);
    }
}

Additional Configuration

The logging system has several configuration options that are provided to make it easier to use in cloud native environments.

• log.output-file can be set to the desired output for logging and also provides a mechanism to stream logs over tcp. Setting this to the format tcp://<host>:<port> will enable the socket logger for tcp streaming.

• log.format can be set to either text or json. When set to json, the log record is formatted as a JSON object, one per line. Any newlines in the field values, such as exception stack traces, will be escaped as normal in the JSON object. This allows for capturing and indexing exceptions as singular fields in a logging search system.

• node.annotation-file allows a file containing fields to be set at startup that can be interpolated from environment variables and will be included in all log output.

  For example:

  #config.properties
  node.annotation-file=annotations.properties
  log.format=json
  

  #annotations.properties
  hostIp=${ENV:HOST_IP}
  podName=${ENV:POD_NAME}
  

  {
    "timestamp": "2021-12-06T16:23:41.352519093Z",
    "level": "DEBUG",
    "thread": "main",
    "logger": "TestLogger",
    "message": "Test Log Message",
    "annotations": {
      "hostIp": "127.0.0.1",
      "podName": "mypod"
    }
  }