Fluent Logging

Introduction

Fluent splunk-friendly logging with automatic escaping. Use this library to have a consistent logging format across your libraries and applications.

Using fluent-logging

Fluent splunk-friendly logging with automatic escaping; e.g

public class Demo {

    public static void main(String[] args) {
        new Demo().run();
    }

    protected void run() {
        // report starting conditions
        final Operation operation = operation("operation").with("argument", UUID.randomUUID()).started(this);
        
        //operation with JSON layout
        final Operation operationJson = Operation.operation("Operation that outputs in JSON format").jsonLayout()
                    .with("argument", UUID.randomUUID()).started(this);

        try {
            // do some things
            int x = 1/0;
            // report success
            operation.wasSuccessful().yielding("result","{\"text\": \"hello world\"}").log();

        } catch(Exception e) {
            // report failure
            operation.wasFailure().throwingException(e).log();
        }
    }
}

Refer Demo.java for full source code of an example.

Operation might log:

09:42:28.503 [main] INFO  Demo - operation=demo id="bd09f108-2a4d-4e47-8b9f-d20c19c0dad0"
09:42:28.543 [main] INFO  Demo - operation=demo id="bd09f108-2a4d-4e47-8b9f-d20c19c0dad0" outcome=success result="{\"text\": \"hello world\"}"
09:47:06.397 [main] INFO Demo - {
  "argument" : "f7ca4805-58e0-449f-8cb1-64bf70588285",
  "logLevel" : "INFO",
  "time" : "2019-09-13T09:47:06.476Z",
  "operation" : "Operation that outputs in JSON format"
}

on success, or:

10:02:13.484 [main] ERROR Demo - operation=demo id="bd09f108-2a4d-4e47-8b9f-d20c19c0dad0" outcome=failure exception="java.lang.ArithmeticException: / by zero"
java.lang.ArithmeticException: / by zero
    at Demo.run(Demo.java:19) [test-classes/:na]
    at Demo.main(Demo.java:10) [test-classes/:na]
    at ...
    
09:47:06.407 [main] ERROR Demo - {
  "exception" : "java.lang.ArithmeticException: / by zero",
  "argument" : "f7ca4805-58e0-449f-8cb1-64bf70588285",
  "logLevel" : "ERROR",
  "errorMessage" : "/ by zero",
  "time" : "2019-09-13T09:47:06.476Z",
  "operation" : "Operation that outputs in JSON format",
  "outcome" : "failure"
}

on failure.

The argument passed to the started() (and, optionally, terminating log()) method is used to derive the logger name, and is usually the object which is the orchestrator of an operation. Alternatively, a specific slf4j logger instance can be passed.

Arguments (passed by with() and yielding() etc.) are escaped to allow Splunk to index them, e.g. double quotes are escaped.

See https://sites.google.com/a/ft.com/technology/systems/membership/logging-conventions for suggested argument key names.

Fluent-Logging outputs in only KV-pairs

To remove plain text from logs and to have only KV pairs as output use following configuration of the repository using Fluent-Logging library:

Dropwizard application:

    logFormat: "logLevel=\"%p\" time=\"%d{yyyy-MM-dd'T'HH:mm:ss.SSSz}\" category=\"%c\" %m%n"

Spring Boot Application:

    logging.pattern.console=logLevel=\"%p\" time=\"%d{yyyy-MM-dd'T'HH:mm:ss.SSSz}\" category=\"%c\" %m%n
    logging.pattern.file=logLevel=\"%p\" time=\"%d{yyyy-MM-dd'T'HH:mm:ss.SSSz}\" category=\"%c\" %m%n

Fluent-Logging outputs in JSON format

Create operation with jsonLayout:

    //operation with JSON layout
    final Operation operationJson = Operation.operation("Operation that outputs in JSON format").jsonLayout()
                    .with("argument", UUID.randomUUID()).started(this);

Internal Release

https://jenkins.memb.ft.com/job/fluent-logging/