Jmap, Jhat, Jstat, Jstack

Jmap

-heap

-histo

-dump

Jhat

Jstat

Jstat–gcutil 2721 Print Time print count

Jstack

Consumes high CPU process, this Java process PID is 3227

Jstack 3227

System consumption is high, whether it is an IO bottleneck (iostat, look at the queue), need to keep track of the kernel call (what to do: strace).

The User application causes the thread ID to be found. How to see which thread ID is higher (top–p 3227 at the command line by H, show threads, sort by P by CPU)

PS-MP 3227-o Thread,tid,time

printf "%x\n" 3324 converted to 16 binary

Online stacks jstack 3227 |grep 16jinzhi

State:

Runnable, wait, monitor

Jmap, Jhat, Jstat, Jstack