In ch.qos.logback.core.rolling.helper.AsynchronousCompressor.compressAsynchronously(String, String, String), a new thread pool is allocated every time to run a single Runnable. When I restart the application, sometimes logback invokes this code hundreds or thousands of times with temporary log file names that do not even exist. For each such invocation, a new thread pool is created, making Eclipse's debugger view with the thread list jump/flash as the new thread is created/removed. Even not considering that, this is a very bad usage of resources. Why not have a fixed thread pool and use it for all asynchronous executions?