We're using log4j successfully in financial B2B / B2C web applications for years. Now we would like to adopt Logback but therefore we need support for an asynchronous appender decorator like log4js AsyncAppender.

Attached you can find my take on this kind of appender cobbled together from ideas and code from various places:

• http://logging.apache.org/log4j/1.2/xref/org/apache/log4j/AsyncAppender.html
• http://jira.qos.ch/browse/LBCLASSIC-20
• http://jira.qos.ch/browse/LBCLASSIC-176
• http://www.simonsite.org.uk/