Hello Anders, Historically, logback's first components were developped with JDK 1.4, and we decided to switch to JDK 1.5 a bit later. The ConcurrentHashMap looks interesting, I'm check it out, thanks! Sébastien Anders Wallgren wrote:

Is there a reason logback isn't taking advantage of the java.util.concurrent package?

For example, LoggerContext uses a Hashtable (which synchronizes all access) rather than a ConcurrentHashMap, which supports lock-free read access.

anders

-- Sébastien Pennec sebastien@qos.ch Logback: The reliable, generic, fast and flexible logging framework for Java. http://logback.qos.ch/