When in embedded mode OpenEJB uses an embedded.logging.properties file packed in our openejb-core jar which use to configure the logging. This logging configuration is a bit lighter than the conf/logging.properties file created in a full standalone OpenEJB setup.
When searching for any config file in the classpath, multiple files with the same name may exist. OpenEJB will always attempt to favor the one closest to the openejb.base variable. This variable is set by default to the current directory where your vm is executing, which is more than likely the directory of your current module. So simply adding a file named embedded.logging.properties to your module may be all that you need to specify a new logging configuration for your tests.
Alternatively, you can set "openejb.logger.external" to "true" as a system property (will not work as an InitialContext property). Then OpenEJB will not attempt to configure logging at all and you can configure logging with Log4j directly using any of its APIs; xml, properties, or code.
There are a couple good reasons for not replacing the embedded.logging.properties file.
As mentioned in Embedded Configuration much can be done with simple overriding. The default embedded.logging.properties is quite good and there is really no need to replace it completely if all you want to do is tweak a few values.
You can also put logging tweaks right in your InitialContext properties like so:
Properties p = new Properties();
p.put(Context.INITIAL_CONTEXT_FACTORY, "org.apache.openejb.core.LocalInitialContextFactory");
p.put("log4j.rootLogger", "fatal,C");
p.put("log4j.category.OpenEJB", "warn");
p.put("log4j.category.OpenEJB.options", "info");
p.put("log4j.category.OpenEJB.server", "info");
p.put("log4j.category.OpenEJB.startup", "info");
p.put("log4j.category.OpenEJB.startup.service", "warn");
p.put("log4j.category.OpenEJB.startup.config", "info");
p.put("log4j.category.OpenEJB.hsql", "info");
p.put("log4j.category.CORBA-Adapter", "info");
p.put("log4j.category.Transaction", "warn");
p.put("log4j.category.org.apache.activemq", "error");
p.put("log4j.category.org.apache.geronimo", "error");
p.put("log4j.category.openjpa", "error");
p.put("log4j.appender.C", "org.apache.log4j.ConsoleAppender");
p.put("log4j.appender.C.layout", "org.apache.log4j.SimpleLayout");
Context context = new InitialContext(p);
Essentially, everything starting with "log4j." gets applied as overrides on top of the embedded.logging.properties we find in the classpath. This makes it possible to easily tweak the log levels while debugging a particular test.
Note, that InitialContext properties can also be supplied in a jndi.properties file in the classpath or via system properties. The overriding order is as follows: 1 = highest, 4 = lowest.
By default there are no logging settings in 1-3, so #4 is the only source of logging information.
For your purposes, here are the contents of the default embedded.logging.properties file contained in OpenEJB 3.1.1
log4j.rootLogger = fatal,C
log4j.category.OpenEJB = warn
log4j.category.OpenEJB.server = info
log4j.category.OpenEJB.startup = info
log4j.category.OpenEJB.startup.service = warn
log4j.category.OpenEJB.startup.config = info
log4j.category.OpenEJB.hsql = info
log4j.category.CORBA-Adapter = info
log4j.category.Transaction = warn
log4j.category.org.apache.activemq = error
log4j.category.org.apache.geronimo = error
log4j.category.openjpa = error
log4j.appender.C = org.apache.log4j.ConsoleAppender
log4j.appender.C.layout = org.apache.log4j.SimpleLayout
Here is that file's location in svn as well as all of the previous versions. Future versions will follow the same pattern.