Single-thread Access
Servlets are inherently multithreaded. However, the servlet container supports a simple mechanism for serializing access to a particular servlet. If a servlet element contains the attribute single-thread="true", the container only allows one thread at a time to enter the servlet. If a new request arrives for the servlet while a thread is active in the servlet, the new request waits until the active thread leaves the servlet.
The servlet element below specifies that only one thread at a time may enter the servletInfo instance.
<servlet single-thread="true">
For more information on the implications of single-thread servlets, and how to address performance issues, see Single-Thread and Multithread Issues, in Chapter 3 of the HydraExpress User Guide.