JVM freezes after switching to jdk1.8.0_74

Question

I have a java application that works fine with java 7. After switching to java 8 with the following confiugration, it started to hang.

-Xms3g -Xmx3g -verbose:gc -XX:+UseG1GC -XX:G1ReservePercent=25 -XX:+PrintGCDateStamps 

I took jstack dump and it shows that all threads are in BLOCKED state. I also took jmap dump, which shows the following information.

Can someone help me in solving this problem?

 Attaching to process ID 2554, please wait... Debugger attached successfully. Server compiler detected. JVM version is 25.74-b02 using thread-local object allocation. Garbage-First (G1) GC with 18 thread(s) Heap Configuration: MinHeapFreeRatio = 40 MaxHeapFreeRatio = 70 MaxHeapSize = 3221225472 (3072.0MB) NewSize = 1363144 (1.2999954223632812MB) MaxNewSize = 1932525568 (1843.0MB) OldSize = 5452592 (5.1999969482421875MB) NewRatio = 2 SurvivorRatio = 8 MetaspaceSize = 21807104 (20.796875MB) CompressedClassSpaceSize = 1073741824 (1024.0MB) MaxMetaspaceSize = 17592186044415 MB G1HeapRegionSize = 1048576 (1.0MB) Heap Usage: G1 Heap: regions = 3072 capacity = 3221225472 (3072.0MB) used = 2112667712 (2014.7969360351562MB) free = 1108557760 (1057.2030639648438MB) 65.58583776156108% used G1 Young Generation: Eden Space: regions = 1665 capacity = 2024800256 (1931.0MB) used = 1745879040 (1665.0MB) free = 278921216 (266.0MB) 86.22475401346452% used Survivor Space: regions = 5 capacity = 5242880 (5.0MB) used = 5242880 (5.0MB) free = 0 (0.0MB) 100.0% used G1 Old Generation: regions = 349 capacity = 1191182336 (1136.0MB) used = 361545792 (344.79693603515625MB) free = 829636544 (791.2030639648438MB) 30.351842960841218% used 18753 interned Strings occupying 1751224 bytes. 

Answer 1

You need to take a stream dump and carefully analyze it to understand where they are stuck, this is most likely a thread safety issue in your code. We faced a similar lock problem in the past when we switched from Linux 4 to Linux 6 (a very powerful machine with several processors and cores). Faster machines may exhibit such long thread-related software errors.