[ovirt-devel] [ATN] [ovirt-engine] engine master logging
Hello All,
Thanks to Martin Perina efforts[1] the ovirt-engine logging was cleaned up significantly
throughout the engine.
1. Logging Facade is slf4j.
2. Logging backend is jboss logging at jboss and java.util.logging at standalone.
3. No more commons-logging, log4j, combinations nor proprietary loggers.
The org.ovirt.engine.core.utils.log.LogFactory and org.ovirt.engine.core.utils.log.Log are
depreciated now, the correlation id is managed using logging MDC, so no need to use
wrapper, and correlation has much wider effect, as also 3rd parties log records are
attached with correlation id.
We will start to push changes to remove the usage of these classes in favor of plain slf4j
loggers.
Quick lineup...
1. Usage:
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
class x {
private static final Logger log = LoggerFactory.getLogger(x.class);
}
2. slf4j logger javadoc is here[2].
3. Crash course:
// simple string
log.info("string");
// string with exception and stack trace
log.info("string", exception);
// string with vars, logger will call argN.toString() for each {}.
log.info("string {} {} {}", arg1, arg2, arg3);
4. *NOTICE* Major difference than what we had:
Exception arguments are not "magically" detected.
// previous (utils Log): "exception" magically detected.
log.infoFormat("string {0}", arg1, exception);
// new (slf4j):
log.info("string {}", arg1);
log.info("Exception", exception);
// better new (slf4j):
log.info("string {}", arg1);
log.debug("Exception", exception);
Please do not hesitate to raise any related issue you may find.
Regards,
Alon Bar-Lev.
[1] https://bugzilla.redhat.com/show_bug.cgi?id=1109871
[2] http://www.slf4j.org/api/org/slf4j/Logger.html