java memory structure
heap memory composition
Garbage Collection Algorithm
Mark-sweep Mark Sweep Disadvantage: Lots of memory fragmentation
Copying copying disadvantages: can only be used with half of the memory new generation
mark-compact mark compression disadvantage: slightly lower efficiency than copy old generation use
garbage collector
serial collector : single thread is rarely used
Parallel collector: parallel recycling java8 default large concurrency jvm needs to stop
CMS collector: short pause times
G1 collector: short pause time and high concurrency
Common parameter settings
Tuning tomcat
