Spring Security deletes session form the database when user logs out - spring

Question

I'm implementing spring security in my project and have used mysql database to store sessions. Everything works fine but when the user logs out, its session is also deleted from the database which I do not want. I only want session to be invalidated but not deleted from the database.
On debugging, I found :
public void logout(HttpServletRequest request, HttpServletResponse response,
Authentication authentication) {
Assert.notNull(request, "HttpServletRequest required");
if (invalidateHttpSession) {
HttpSession session = request.getSession(false);
if (session != null) {
logger.debug("Invalidating session: " + session.getId());
**session.invalidate();**
}
}
if (clearAuthentication) {
SecurityContext context = SecurityContextHolder.getContext();
context.setAuthentication(null);
}
SecurityContextHolder.clearContext();
}
This code is from SecurityContextLogoutHandler class.
Further, the code execution goes in:
private final class HttpSessionWrapper extends HttpSessionAdapter<S> {
HttpSessionWrapper(S session, ServletContext servletContext) {
super(session, servletContext);
}
#Override
public void invalidate() {
super.invalidate();
SessionRepositoryRequestWrapper.this.requestedSessionInvalidated = true;
setCurrentSession(null);
clearRequestedSessionCache();
**SessionRepositoryFilter.this.sessionRepository.deleteById(getId());**
}
}
The last line of the function deletes the session which I do not want.
My question is can I stop spring security from deleting sessions from the DB when user logs out or this is how spring security works?

Answer 1

Is there any specific reason why you don't want to delete session from DB once user log's out ? This is pretty much common behavior. Session is representing your logged in client. Once client log's in (provide valid credentials, password with username for example) session ID is created and sent to client. This session ID is representing valid logged in connection. On subsequent request's from this client he will only send this session ID inside header, your app will check if this session ID is stored inside valid session's (your DB for example) and if it is this request is considered authenticated (therefore client doesn't have to send his credential's which has to be verified with each request, he is only sending session ID). Once client log's out the session ID is invalidated since with logout his connection is no longer authenticated. Therefore yes this is how spring security work's, there is no need to persist invalidated session's. You would also have to implement custom mechanism for clearing session's from DB (when will be session cleared if not at time of user logout). Also you might consider to use session pool inside memory instead of DB.
Edit: i don't how spring check's valid session's in case of DB session pool but at some time it has to access DB read all session's so it can find out which session ID's are valid (i guess this is done for each after - login request at least). How could be invalidated session in your case be persisted inside database session pool when valid session's are defined by that pool at same time ?