Logzio Log4j 2 Appender

Log4j 2 Appender that ships logs using HTTPS bulk

This appender sends logs to your Logz.io account, using non-blocking threading, bulks, and HTTPS encryption. Please note that this appender requires log4j version 2.7 and up, and java 8 and up.

Technical Information

This appender uses LogzioSender implementation. Once you send a log, it will be enqueued in the queue and 100% non-blocking. There is a background task that will handle the log shipment for you. This jar is an "Uber-Jar" that shades both LogzioSender, BigQueue, Gson and Guava to avoid "dependency hell".

Installation from maven

JDK 8:

    <dependency>
        <groupId>io.logz.log4j2</groupId>
        <artifactId>logzio-log4j2-appender</artifactId>
        <version>1.0.19</version>
    </dependency>

JDK 11 and above:

    <dependency>
        <groupId>io.logz.log4j2</groupId>
        <artifactId>logzio-log4j2-appender</artifactId>
        <version>2.0.1</version>
    </dependency>

The appender also requires a logger implementation, for example:

    <dependency>
        <groupId>org.apache.logging.log4j</groupId>
        <artifactId>log4j-slf4j-impl</artifactId>
        <version>2.15.0</version>
    </dependency>

Log4 2 Example Configuration

    <Appenders>
        <LogzioAppender name="Logzio">
            <logzioToken>your-logzio-personal-token-from-settings</logzioToken>
            <logzioType>myAwesomeType</logzioType>
            <logzioUrl>https://listener.logz.io:8071</logzioUrl>
        </LogzioAppender>
       
    </Appenders>
    <Loggers>
        <Root level="info">
            <AppenderRef ref="Logzio"/>
        </Root>
    </Loggers>

Parameters

Parameter	Default	Explained
logzioToken	None	Your Logz.io token, which can be found under "settings" in your account, If the value begins with $ then the appender looks for an environment variable or system property with the name specified. For example: $LOGZIO_TOKEN will look for environment variable named LOGZIO_TOKEN
logzioType	java	The log type for that appender, it must not contain any spaces
logzioUrl	https://listener.logz.io:8071	The url that the appender sends to. If your account is in the EU you must use https://listener-eu.logz.io:8071
drainTimeoutSec	5	How often the appender should drain the queue (in seconds)
socketTimeoutMs	10 * 1000	The socket timeout during log shipment
connectTimeoutMs	10 * 1000	The connection timeout during log shipment
addHostname	false	Optional. If true, then a field named 'hostname' will be added holding the host name of the machine. If from some reason there's no defined hostname, this field won't be added
additionalFields	None	Optional. Allows to add additional fields to the JSON message sent. The format is "fieldName1=fieldValue1;fieldName2=fieldValue2". You can optionally inject an environment variable value using the following format: "fieldName1=fieldValue1;fieldName2=$ENV_VAR_NAME". In that case, the environment variable should be the only value. In case the environment variable can't be resolved, the field will be omitted.
debug	false	Print some debug messages to stdout to help to diagnose issues
compressRequests	false	Boolean. true if logs are compressed in gzip format before sending. false if logs are sent uncompressed.
exceedMaxSizeAction	"cut"	String. cut to truncate the message field or drop to drop log that exceed the allowed maximum size for logzio. If the log size exceeding the maximum size allowed after truncating the message field, the log will be dropped.

Parameters for in-memory queue

Parameter	Default	Explained
inMemoryQueueCapacityBytes	1024 * 1024 * 100	The amount of memory(bytes) we are allowed to use for the memory queue. If the value is -1 the sender will not limit the queue size.
inMemoryLogsCountCapacity	-1	Number of logs we are allowed to have in the queue before dropping logs. If the value is -1 the sender will not limit the number of logs allowed.
inMemoryQueue	false	Set to true if the appender uses in memory queue. By default the appender uses disk queue

Parameters for disk queue

Parameter	Default	Explained
fileSystemFullPercentThreshold	98	The percent of used file system space at which the sender will stop queueing. When we will reach that percentage, the file system in which the queue is stored will drop all new logs until the percentage of used space drops below that threshold. Set to -1 to never stop processing new logs
gcPersistedQueueFilesIntervalSeconds	30	How often the disk queue should clean sent logs from disk
bufferDir(deprecated, use queueDir)	System.getProperty("java.io.tmpdir")	Where the appender should store the queue
queueDir	System.getProperty("java.io.tmpdir")	Where the appender should store the queue

Code Example

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;

public class LogzioLog4j2Example {

    public static void main(String[] args) {
        Logger logger = LogManager.getLogger(LogzioLog4j2Example.class);
        
        logger.info("Testing logz.io!");
        logger.warn("Winter is coming");
    }
}

MDC

Each key value you will add to MDC will be added to each log line as long as the thread alive. No further configuration needed.

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.ThreadContext;

public class LogzioLog4j2Example {

    public static void main(String[] args) {
        Logger logger = LogManager.getLogger(LogzioLog4j2Example.class);
        
        ThreadContext.put("Key", "Value");
        logger.info("This log will hold the MDC data as well");
    }
}

Will send a log to Logz.io that looks like this:

{
    "message": "This log will hold the MDC data as well",
    "Key": "Value",
    ... (all other fields you used to get)
}

Marker

Markers are named objects used to enrich log statements, so each log line will be enriched with its own. No further configuration needed.

import org.apache.logging.log4j.LogManager;
import org.apache.logging.log4j.Logger;
import org.apache.logging.log4j.Marker;
import org.apache.logging.log4j.MarkerManager;

public class LogzioLog4j2Example {

    public static void main(String[] args) {
        Logger logger = LogManager.getLogger(LogzioLog4j2Example.class);
        Marker marker = MarkerManager.getMarker("Fatal");
        logger.error(marker, "This line has a fatal error");
    }
}

Will send a log to Logz.io that looks like this:

{
    "message": "This line has a fatal error",
    "Marker": "Fatal",
    ... (all other fields you used to get)
}

Build and test locally

1. Clone the repository:

git clone https://github.com/logzio/logzio-log4j2-appender.git
cd logzio-log4j2-appender

2. Build and run tests:

mvn clean compile
mvn test

Release notes

• 2.1.0
  • Updated LogzioSender version to 2.1.0
    • Upgrade packages version
  • Upgrade packages version
• 2.0.1
  • Updated LogzioSender version to 2.0.1
    • Add User-Agent header with logz.io information
• 2.0.0 - THIS IS A SNAPSHOT RELEASE - SUPPORTED WITH JDK 11 AND ABOVE
  • Updated LogzioSender version to 2.0.0:
    • Fixes an issue where DiskQueue was not clearing disk space when using JDK 11 and above.
• 1.0.19
  • Updated LogzioSender version to 1.1.8:
    • Fix an issue where log is not being truncated properly between size of 32.7k to 500k.
• 1.0.18
  • updated logzio sender version, fixing IndexOutOfBounds exception with bigqueue

Expand to check old versions

• 1.0.16
  • Added exceedMaxSizeAction parameter for handling oversized logs.
• 1.0.15
  • Bump versions of log4j-core
• 1.0.14
  • Bump versions of log4j-api and log4j-core
• 1.0.13
  • Fix for issue #38, thanks to @idachev
  • Bump versions of log4j and guava
• 1.0.11
  • add in memory queue option
  • change bufferDir(deprecated) to queueDir
• 1.0.10
  • Allow to set type using environment variables.
• 1.0.9
  • fix guava shaded dependency.
• 1.0.8
  • added compressRequests parameter to enable gzip compression of the logs before they are sent.
  • added option to inject system property value into additionalFields, logzioUrl and token.
• 1.0.6 - 1.0.7
  • fix issue: Guava and logzio.sender libraries are shaded but still a dependency
• 1.0.5
  • fix an issue: Log4j2 version 2.8.2 throws exception - backward compatibility problem
• 1.0.3 - 1.0.4
  • add error message about reason of 400(BAD REQUEST)
• 1.0.2
  • Fix problem where logzioToken and logzioUrl could not be environment variables
• 1.0.1
  • Fixed an issue: LogzioAppender does not let the JVM exit
• 1.0.0
  • Initial releases

Contribution

• Fork
• Code
• mvn test
• Issue a PR :)