I suspect that the slow startup in Jetty 9.2.10 is caused by annotation scanning. This wiki page describes the problem and provides a remedy:
As the page says:
"Since servlet 3.0 (supported by jetty-8.x), there has been the added requirement that both container and webapp jars can be scanned."
Some further research suggests that there are other plausible explanations. If the solution in the above wiki page doesn't help, I suggest that you:
Turn on verbose logging an try to narrow down what phase of the startup is taking the time.
Attach a profiler and find out where the startup code hotspots are.
Use external performance monitoring (e.g. the Windows Task Manager) to see if the JVM is busy or idle during the long startup.
These should give you some clues to help you / us diagnose the real problem.
