jenkins is waitingf for response

For the first time，it will be normal when I restart the tomcat.

It didn't take long to hang on.

I executed the command: jstack [tomcat_pid], find my access is blocked.

"Handling POST /jenkins/view/%E6%95%B0%E6%8D%AE%E4%B8%9A%E5%8A%A1%E7%BA%BF/ajaxExecutors from [MY IP] : http-nio-8080-exec-3" #56 daemon prio=5 os_prio=0 tid=0x00007f1810004800 nid=0x3ad waiting for monitor entry [0x00007f189e460000]
java.lang.Thread.State: BLOCKED (on object monitor)

It takes a long time for normal access and then is wait for response.I don't know how to slove it.

Is it due to insufficient memory?

Looking forward to your reply