Fwd: Change in log level removes appenders attached to async appender

[piyush goyal]

Hi Team,

We are trying to writing our custom appenders on top of sling in AEM and
referred to documentation
<https://sling.apache.org/documentation/development/logging.html#appenders-as-osgi-services>.
We want to send logs of the configured loggers to redis. For this, we wrote
a custom Redis Appender extending UnsynchronizedAppenderBase which would
just send the logs to redis. This redis appender is wrapped inside an async
appender which is getting registered as an OSGI service after reading the
redis related configurations from config manager page. Below is a small
snapshot of the custom code:

       redisAppender = new RedisAppender(host, port, redisList);
asyncAppender = new AsyncAppender();
        asyncAppender.setName("ASYNC");
        asyncAppender.setDiscardingThreshold(0);
        asyncAppender.addAppender(this.redisAppender);

        Dictionary<String, Object> asyncProps = new Hashtable<String,
Object>();

        String[] loggers = {
                "com.foo.base"
        };

        asyncAppenderRegistration =
bundleContext.registerService(Appender.class.getName(), asyncAppender,
asyncProps);


  As soon as the async appender is registered as a service, we can see our
logs reaching the redis instance. Since no logging level is defined for the
logger, it inherits from the ROOT logger which is by default INFO. The
problem comes when we try to change the log level of ROOT logger. We saw
that when we change the log level, logbackManager class is called and a
context reset method is executed. After this process, although Async
Appender is still linked to the defined loggers, but async appender looses
the redis appender attached to it.

I tried doing the same process with config fragment as well, but everytime
a change in log level causes redis appender to be detached from the async
appender. I even tried creating factory.config so that I can directly
change the logger level of the my logger and not inheriting it from ROOT
level. But here also async appender detaches the redis appender attached to
it.

What could be the reason behind it? And what should be the correct approach
to be taken so that after changing the log level, async appender does not
detach redis appender.

Thanks and Regards
Piyush Goyal