1. jstack command
View thread stack information within a Java process.
jstack can locate the thread stack, the stack according to the information we can locate specific code , so it is very much in use JVM performance tuning.
2. Hot CPU issues:
cpu occupancy rate has continued relatively high
Positioning steps:
jps -m -l list the running processes ---- whether here with the top command better? top to see who occupied the highest cpu
top -H -p pid process to find the most cost within the cpu thread
printf "% x \ n" tid thread id into hexadecimal
jstack pid | grep converted to hexadecimal tid -A 50
Note 1: The information shown, focusing on the code I have written, to develop screenshots
Note 2: There may be a jstack not capture the information you need, you need to perform many times, because the state is caught in the moment
3. java.lang.stackoverflowerror,fatal:stack size too small
Parameters: -Xss: stack size for each thread that holds the function call, such as the return address, the default 1M, if error, instead 2M
Code: capturing memory snapshots, go to troubleshoot the code, there may be too many levels of recursive calls
