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

    <dependency>
        <groupId>io.logz.log4j2</groupId>
        <artifactId>logzio-log4j2-appender</artifactId>
        <version>1.0.10</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.

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");
    }
}