I'm using pax-logging-api along with pax-logging-log4j2 for logging from my OSGi bundles. I would like to utilize Log4J2's StructuredDataMessage (using EventLogger) to write some messages to a database. However, I'm unable to read the values I put into the StructuredDataMessage from the appenders when using Pax Logging.
The following works in a non-OSGi project using the Log4J2 libraries directly:
log4j2.properties:
appender.console.type = Console
appender.console.name = STDOUT
appender.console.layout.type = PatternLayout
appender.console.layout.pattern = %m%n
appender.event.type = Console
appender.event.name = event
appender.event.layout.type = PatternLayout
appender.event.layout.pattern = %marker ${sd:id} ${sd:testKey} %n %m%n
rootLogger.level = debug
rootLogger.appenderRef.console.ref = STDOUT
logger.event.name = EventLogger
logger.event.level = debug
logger.event.appenderRef.console.ref = event
logger.event.additivity = false
Test.java:
public class Test {
private static final Logger LOGGER = LogManager.getLogger(Test.class);
public static void main(String[] args) {
StructuredDataMessage msg = new StructuredDataMessage("1", "message", "event");
msg.put("testKey", "testValue");
LOGGER.info(msg);
EventLogger.logEvent(msg);
}
}
Output:
1 testValue event [1 testKey="testValue"] message
EVENT 1 testValue
event [1 testKey="testValue"] message
Note that the event appender properly dereferenced the sd keys from the StructuredDataMessage.
However, the following does not work in OSGi with pax-logging:
org.ops4j.pax.logging.cfg:
log4j2.appender.console.type = Console
log4j2.appender.console.name = STDOUT
log4j2.appender.console.layout.type = PatternLayout
log4j2.appender.console.layout.pattern = %m%n
log4j2.appender.event.type = Console
log4j2.appender.event.name = event
log4j2.appender.event.layout.type = PatternLayout
log4j2.appender.event.layout.pattern = %marker \$\\\{sd:id\} \$\\\{sd:testKey\} %n %m%n
log4j2.rootLogger.level = debug
log4j2.rootLogger.appenderRef.console.ref = STDOUT
log4j2.logger.event.name = EventLogger
log4j2.logger.event.level = debug
log4j2.logger.event.appenderRef.console.ref = event
log4j2.logger.event.additivity = false
Test.java:
public class Test implements BundleActivator {
private static final Logger LOGGER = LogManager.getLogger(Test.class);
@Override
public void start(BundleContext context) throws Exception {
StructuredDataMessage msg = new StructuredDataMessage("1", "message", "event");
msg.put("testKey", "testValue");
LOGGER.info(msg);
EventLogger.logEvent(msg, Level.INFO);
}
@Override
public void stop(BundleContext context) throws Exception {
}
}
Output:
event [1 testKey="testValue"] message
EVENT ${sd:id} ${sd:testKey}
event [1 testKey="testValue"] message
Is there a trick to getting this to work in pax-logging? I am able to access values from the MDC using \$\\\{ctx:key\} when applicable, so I'm assuming the syntax is similar. I've also tried using the lookups in patterns for RoutingAppender, FileAppender, etc. to no avail.
Thanks in advance!
Edit: I'm using the latest version of pax-logging-api and pax-logging-log4j2 (1.11.3)
OK, it's not yet a definitive answer - simply comment is too short to describe what happens.
The stack trace with your call is:
"pipe-restart 238@10666" prio=5 tid=0xc3 nid=NA runnable
java.lang.Thread.State: RUNNABLE
at org.ops4j.pax.logging.log4j2.internal.PaxLoggerImpl.doLog0(PaxLoggerImpl.java:354)
at org.ops4j.pax.logging.log4j2.internal.PaxLoggerImpl.doLog(PaxLoggerImpl.java:337)
at org.ops4j.pax.logging.log4j2.internal.PaxLoggerImpl.inform(PaxLoggerImpl.java:233)
at org.ops4j.pax.logging.internal.TrackingLogger.inform(TrackingLogger.java:209)
at org.ops4j.pax.logging.log4jv2.Log4jv2Logger.logMessage(Log4jv2Logger.java:162)
at org.apache.logging.log4j.spi.AbstractLogger.log(AbstractLogger.java:2102)
at org.apache.logging.log4j.spi.AbstractLogger.tryLogMessage(AbstractLogger.java:2190)
at org.apache.logging.log4j.spi.AbstractLogger.logMessageTrackRecursion(AbstractLogger.java:2144)
at org.apache.logging.log4j.spi.AbstractLogger.logMessageSafely(AbstractLogger.java:2127)
at org.apache.logging.log4j.spi.AbstractLogger.logIfEnabled(AbstractLogger.java:1828)
at org.apache.logging.log4j.EventLogger.logEvent(EventLogger.java:56)
at grgr.test.ActivatorLogging.start(ActivatorLogging.java:39)
...
org.ops4j.pax.logging.log4jv2.Log4jv2Logger.logMessage() is bridge between logging facade and logging backend.
Remember - with pax-logging, you can, say, use Commons Logging facade with Log4J1 backend, or Log4j2 facade (and that's what you're doing) with e.g., Logback backend.
That's why org.ops4j.pax.logging.log4jv2.Log4jv2Logger.logMessage() does this:
} else if (level.intLevel() >= Level.INFO.intLevel()) {
m_delegate.inform(paxMarker, message.getFormattedMessage(), t, fqcn);
and your structured message is changed into String event [1 testKey="testValue"] message.
Only then configured appenders are called - and the appender with layout that extract structured data can't find it, because the structured message is already converted to plain String.
These 3 lines:
at org.ops4j.pax.logging.log4j2.internal.PaxLoggerImpl.inform(PaxLoggerImpl.java:233)
at org.ops4j.pax.logging.internal.TrackingLogger.inform(TrackingLogger.java:209)
at org.ops4j.pax.logging.log4jv2.Log4jv2Logger.logMessage(Log4jv2Logger.java:162)
do the crossing from pax-logging-api (facade) through TrackingLogger (bridge) to pax-logging-log4j2 (backend) losing structured information in between.
I've created https://ops4j1.jira.com/browse/PAXLOGGING-302 and hope to do something about it soon.
EDIT1
The key is that in org.apache.logging.log4j.core.lookup.StructuredDataLookup#lookup(), this condition is true:
if (event == null || !(event.getMessage() instanceof StructuredDataMessage)) {
return null;
}
EDIT2
I've just fixed https://ops4j1.jira.com/browse/PAXLOGGING-302 and this test proves it works:
Logger logger = LogManager.getLogger("my.logger");
logger.info(new StructuredDataMessage("1", "hello!", "typeX").with("key1", "sd1"));
logger.info(new StringMapMessage().with("key1", "map1"));
List<String> lines = readLines();
assertTrue(lines.contains("my.logger/org.ops4j.pax.logging.it.Log4J2MessagesIntegrationTest typeX/sd1 [INFO] typeX [1 key1=\"sd1\"] hello!"));
assertTrue(lines.contains("my.logger/org.ops4j.pax.logging.it.Log4J2MessagesIntegrationTest ${sd:type}/map1 [INFO] key1=\"map1\""));
the configuration is:
log4j2.appender.console.type = Console
log4j2.appender.console.name = console
log4j2.appender.console.layout.type = PatternLayout
log4j2.appender.console.layout.pattern = %c/%C ${sd:type}/${map:key1} [%p] %m%n
log4j2.rootLogger.level = info
log4j2.rootLogger.appenderRef.file.ref = console
(you have to use the escape sequences you've used, if configuring via etc/org.ops4j.pax.logging.cfg in Karaf).