Configuration of the log level?

[jmini]

I am not familiar with OSGi specifications in general and R7 in particular...

When using traditional logback (in JavaSE application) the log level can be configured with some xml or properties file present on the classpath. How does it work with pax-logging-logback?

I am just willing to change the level from INFO to WARNING.

[grgrzybek]

pax-logging configures it's backend with the help of Configuration Admin. In particular, it manages a PID (Persistence IDentifier) named org.ops4j.pax.logging.

In Apache Karaf, these configurations may be managed using Felix Fileinstall and files named ${karaf.base}/etc/<pid>.cfg. Here it'd be ${karaf.base}/etc/org.ops4j.pax.logging.cfg.

Because Logback can be configured only using XML file, you need to specify one option:

org.ops4j.pax.logging.logback.config.file = /path/to/logback.xml

This target file is simply a Logback configuration file and you can do whatever you want there.

Please have a look at documentation page: https://ops4j1.jira.com/wiki/spaces/paxlogging/pages/499351734/Configuring+Logback

If you have any questions, please add them here.

[jmini]

Thank you for your explanations

I didn't really managed to make it work for now.

In my bundle I have added a service to configure the Logback (If I understood what you indicated):

import java.io.IOException;
import java.util.Hashtable;

import org.osgi.service.cm.Configuration;
import org.osgi.service.cm.ConfigurationAdmin;
import org.osgi.service.component.ComponentContext;
import org.osgi.service.component.annotations.Activate;
import org.osgi.service.component.annotations.Component;
import org.osgi.service.component.annotations.Reference;

@Component(service = ConfigurationServiceImpl.class, immediate = true)
public class ConfigurationServiceImpl {

    @Reference
    private ConfigurationAdmin cm;

    @Activate
    protected void activate(ComponentContext context) {
        System.out.println("XXX ACTIVATE");
        try {
            Configuration config = cm.getConfiguration("org.ops4j.pax.logging");
            Hashtable<String, Object> props = new Hashtable<>();
            props.put("org.ops4j.pax.logging.logback.config.file", "/path/to/logback.xml");
            config.update(props);
            System.out.println("XXX CONFIG APPLIED");
        } catch (IOException e) {
            e.printStackTrace();
        }
    }
}

Where /path/to/logback.xml is a other path on my machine pointing to a real file containing:

<configuration>
    <appender name="console" class="ch.qos.logback.core.ConsoleAppender">
        <encoder class="ch.qos.logback.core.encoder.LayoutWrappingEncoder">
            <layout class="ch.qos.logback.classic.layout.TTLLLayout" />
        </encoder>
    </appender>

    <root level="ERROR">
        <appender-ref ref="console" />
    </root>
</configuration>

---

But in an other service where I have the code some lines to create a log entry with different levels:

LOG.error("ERROR log");
LOG.warn("WARN log");
LOG.info("INFO log");

I still have this all in the logs, when I would expect to see only the ERROR one.

15:47:18.903 [Test worker] ERROR fr.jmini.abundle.impl.AServiceImpl -- ERROR log
15:47:18.926 [Test worker] WARN fr.jmini.abundle.impl.AServiceImpl -- WARN log
15:47:18.927 [Test worker] INFO fr.jmini.abundle.impl.AServiceImpl -- INFO log

---

There is also this unhealthy error output:

SLF4J: Class path contains multiple SLF4J providers.
SLF4J: Found provider [ch.qos.logback.classic.spi.LogbackServiceProvider@5542c4ed]
SLF4J: Found provider [org.ops4j.pax.logging.slf4j.PaxLoggingSLF4JServiceProvider@1573f9fc]
SLF4J: See https://www.slf4j.org/codes.html#multiple_bindings for an explanation.
SLF4J: Actual provider is of type [ch.qos.logback.classic.spi.LogbackServiceProvider@5542c4ed]

[grgrzybek]

I'd have to see your deployment configuration - looks like you're not using Karaf.
Also (while it sounds like chicken & egg situation), Pax Logging logs information about configuring logging...

If you set framework properties:

• org.ops4j.pax.logging.DefaultServiceLog.level = DEBUG
• org.ops4j.pax.logging.useFileLogFallback = /path/to/file.log

you'll see information about how Pax Logging configures logback.

If you could share your project via GitHub, I could have a look too.

[jmini]

At the end, changing the global log level to an higher level than INFO (like ERROR or WARN) is all I need, so I will go with that.

Thank you very much!