I read somewhere use of webservcies in apps. After a lot of research I am able to create one Webservice which will accept Json and JsonP both format as request and response accordingly. I developed the webservcies using Java, Apache Axis2, Hibernate and MySQL as database. there are few problems and I dont know how to solve ?

1. Insert or delete option, sometimes if at a time more than two users call that service that is insert or delete any row the queries go in sleep mode and next time someone tries to fetch that service he couldnt. Accroding to server log it says error SQL Lockout State. If I checks Processlist in MYSQL it is showing that query in Sleep, I have to kill to resume.
2. The performance of webservice doesnt seems to be upto mark, it takes time some more time as what i experienced it shouldn't. In simple words how to obtain better performance by the services
3. How to implement security feature such that if a user logins he/she can be provided an id and validation of that id so that unauthorized access can be prevented

Or just guide me what should be the most appropriate and optmized Webservice methodology that can be used using Java