Logback

The raven-logback library provides Logback support for Raven via an Appender that sends logged exceptions to Sentry.

The source can be found on Github.

Installation

Using Maven:

<dependency>
    <groupId>com.getsentry.raven</groupId>
    <artifactId>raven-logback</artifactId>
    <version>7.8.6</version>
</dependency>

Using Gradle:

compile 'com.getsentry.raven:raven-logback:7.8.6'

Using SBT:

libraryDependencies += "com.getsentry.raven" % "raven-logback" % "7.8.6"

For other dependency managers see the central Maven repository.

Usage

The following example configures a ConsoleAppender that logs to standard out at the INFO level and a SentryAppender that logs to the Sentry server at the WARN level. The ConsoleAppender is only provided as an example of a non-Sentry appender that is set to a different logging threshold, like one you may already have in your project.

Example configuration using the logback.xml format:

<configuration>
    <!-- Configure the Console appender -->
    <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <!-- Configure the Sentry appender, overriding the logging threshold to the WARN level -->
    <appender name="Sentry" class="com.getsentry.raven.logback.SentryAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>WARN</level>
        </filter>
    </appender>

    <!-- Enable the Console and Sentry appenders, Console is provided as an example
         of a non-Raven logger that is set to a different logging threshold -->
    <root level="INFO">
        <appender-ref ref="Console" />
        <appender-ref ref="Sentry" />
    </root>
</configuration>

Next, you’ll need to configure your DSN (client key) and optionally other values such as environment and release. See below for the two ways you can do this.

Configuration via Runtime Environment

This is the most flexible method for configuring the SentryAppender, because it can be easily changed based on the environment you run your application in.

The following can be set as System Environment variables:

SENTRY_EXAMPLE=xxx java -jar app.jar

Or as Java System Properties:

java -Dsentry.example=xxx -jar app.jar

Configuration parameters follow:

Environment variable Java System Property Example value Description
SENTRY_DSN sentry.dsn https://host:port/1?options Your Sentry DSN (client key), if left blank Raven will no-op
SENTRY_RELEASE sentry.release 1.0.0 Optional, provide release version of your application
SENTRY_ENVIRONMENT sentry.environment production Optional, provide environment your application is running in
SENTRY_SERVERNAME sentry.servername server1 Optional, override the server name (rather than looking it up dynamically)
SENTRY_RAVENFACTORY sentry.ravenfactory com.foo.RavenFactory Optional, select the ravenFactory class
SENTRY_TAGS sentry.tags tag1:value1,tag2:value2 Optional, provide tags
SENTRY_EXTRA_TAGS sentry.extratags foo,bar,baz Optional, provide tag names to be extracted from MDC

Configuration via Static File

You can also configure everything statically within the logback.xml file itself. This is less flexible and not recommended because it’s more difficult to change the values when you run your application in different environments.

Example configuration in the logback.xml file:

<configuration>
    <!-- Configure the Console appender -->
    <appender name="Console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder>
            <pattern>%d{HH:mm:ss.SSS} [%thread] %-5level %logger{36} - %msg%n</pattern>
        </encoder>
    </appender>

    <!-- Configure the Sentry appender, overriding the logging threshold to the WARN level -->
    <appender name="Sentry" class="com.getsentry.raven.logback.SentryAppender">
        <filter class="ch.qos.logback.classic.filter.ThresholdFilter">
            <level>WARN</level>
        </filter>

        <!-- Set Sentry DSN -->
        <dsn>https://host:port/1?options</dsn>

        <!-- Optional, provide release version of your application -->
        <release>1.0.0</release>

        <!-- Optional, provide environment your application is running in -->
        <environment>production</environment>

        <!-- Optional, override the server name (rather than looking it up dynamically) -->
        <serverName>server1</serverName>

        <!-- Optional, select the ravenFactory class -->
        <ravenFactory>com.foo.RavenFactory</ravenFactory>

        <!-- Optional, provide tags -->
        <tags>tag1:value1,tag2:value2</tags>

        <!-- Optional, provide tag names to be extracted from MDC -->
        <extraTags>foo,bar,baz</extraTags>
    </appender>

    <!-- Enable the Console and Sentry appenders, Console is provided as an example
         of a non-Raven logger that is set to a different logging threshold -->
    <root level="INFO">
        <appender-ref ref="Console" />
        <appender-ref ref="Sentry" />
    </root>
</configuration>

Additional Data

It’s possible to add extra data to events thanks to the MDC system provided by Logback.

Mapped Tags

By default all MDC parameters are stored under the “Additional Data” tab in Sentry. By specifying the extraTags parameter in your configuration file you can choose which MDC keys to send as tags instead, which allows them to be used as filters within the Sentry UI.

<extraTags>Environment,OS</extraTags>
void logWithExtras() {
    // MDC extras
    MDC.put("Environment", "Development");
    MDC.put("OS", "Linux");

    // This sends an event where the Environment and OS MDC values are set as tags
    logger.error("This is a test");
}

In Practice

import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.slf4j.MDC;
import org.slf4j.MarkerFactory;

public class MyClass {
    private static final Logger logger = LoggerFactory.getLogger(MyClass.class);
    private static final Marker MARKER = MarkerFactory.getMarker("myMarker");

    void logSimpleMessage() {
        // This sends a simple event to Sentry
        logger.error("This is a test");
    }

    void logWithTag() {
        // This sends an event with a tag named 'logback-Marker' to Sentry
        logger.info(MARKER, "This is a test");
    }

    void logWithExtras() {
        // MDC extras
        MDC.put("extra_key", "extra_value");
        // This sends an event with extra data to Sentry
        logger.info("This is a test");
    }

    void logException() {
        try {
            unsafeMethod();
        } catch (Exception e) {
            // This sends an exception event to Sentry
            logger.error("Exception caught", e);
        }
    }

    void unsafeMethod() {
        throw new UnsupportedOperationException("You shouldn't call this!");
    }
}