Running out of DB connections!
问题 I'm running a Spring/Hibernate connecting to MySQL setup using c3p0 as my connection pool. For some bizarre reason it runs out of connections when the system is under load (of course). The site was pretty stable until we started hitting a new level of traffic (over a hundred concurrent users). At that point the DB would melt down (peg the CPU). My first action was in the application to improve performance through extensive caching and optimization of queries etc. Now it will just run out of