Is there a Logback Layout that Creates JSON Objects with Message Parameters as Attributes?

Question

I want to send log events to Loggly as JSON objects with parameterized string messages. Our project currently has a lot of code that looks like this:

String some         


        

Answer 1

So for me I was trying to log execution times, I created a pojo called ExecutionTime with name, method, class, duration.

I was then able to create it:

ExecutionTime time = new ExecutionTime("Controller Hit", methodName, className, sw.getTotalTimeMillis());

For logging I then used:

private final Logger logger = LoggerFactory.getLogger(this.getClass());
logger.info(append("metric", time), time.toString());

Make sure you have:

import static net.logstash.logback.marker.Markers.append;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

This will log something like this:

{  
   "ts":"2017-02-16T07:41:36.680-08:00",
   "msg":"ExecutionTime [name=Controller Hit, method=setupSession, className=class com.xxx.services.controllers.SessionController, duration=3225]",
   "logger":"com.xxx.services.metrics.ExecutionTimeLogger",
   "level":"INFO",
   "metric":{  
      "name":"Controller Hit",
      "method":"setupSession",
      "className":"class com.xxx.services.controllers.SessionController",
      "duration":3225
   }
}

Might be a different set up as I was using logback-spring.xml to output my logs to json:

<?xml version="1.0" encoding="UTF-8"?>
<configuration>
    <include resource="org/springframework/boot/logging/logback/base.xml"/>
    <property name="PROJECT_ID" value="my_service"/>
    <appender name="FILE" class="ch.qos.logback.core.rolling.RollingFileAppender">
        <File>app/logs/${PROJECT_ID}.json.log</File>
        <encoder class="net.logstash.logback.encoder.LogstashEncoder">
            <fieldNames>
                <timestamp>ts</timestamp>
                <message>msg</message>
                <thread>[ignore]</thread>
                <levelValue>[ignore]</levelValue>
                <logger>logger</logger>
                <version>[ignore]</version>
            </fieldNames>
        </encoder>
        <rollingPolicy class="ch.qos.logback.core.rolling.FixedWindowRollingPolicy">
            <maxIndex>10</maxIndex>
            <FileNamePattern>app/logs/${PROJECT_ID}.json.log.%i</FileNamePattern>
        </rollingPolicy>
        <triggeringPolicy class="ch.qos.logback.core.rolling.SizeBasedTriggeringPolicy">
            <MaxFileSize>20MB</MaxFileSize>
        </triggeringPolicy>
    </appender>
    <logger name="com.xxx" additivity="false" level="DEBUG">
        <appender-ref ref="FILE"/>
        <appender-ref ref="CONSOLE"/>
    </logger>
    <root level="WARN">
        <appender-ref ref="FILE"/>
    </root>
</configuration>

Answer 2

Here's a recently created project that provides a JSON-specific logging API and works with SLF4J:

https://github.com/savoirtech/slf4j-json-logger

Answer 3

Like already answered you'll get a one-dimensional JSON tree with MDC and/or using a Marker with logstash-logback-encoder.

If you are also looking for the following:

• codebooks for definition of logged datatype key and type,
• configuration of log-aggregation tools (like elasticsearch)
• generated Java helper-code for efficient and correct logging

then try a project I've created: json-log-domain. It defines a simple YAML-format definition from which the above can be generated.

An example helper-code statement would be

logger.info(host("localhost").port(8080), "Hello world");

while generated markdown would like something like this.

Answer 4

You could use a Mapped Diagnostic Context to set a stamp for each of those type of log messages that you could then filter on once in loggly.

According to the source of JsonLayout the stamp is stored as a separate value in the JSON.

Answer 5

There is a JSON logstash encoder for Logback, logstash-logback-encoder