what is this number indicates in load on startup tag
This is what I found in the Servlet 2.3 Specification document.
The load-on-startup element indicates that this servlet should be
loaded on the startup of the web application.
The optional contents of these element must be a positive integer
indicating the order in which the servlet should be loaded.
Lower integers are loaded before higher integers.
If no value is specified, or if the value specified is not a positive
integer, the container is free to load it at any time in the startup