Details of error reporting:

ERROR  | wrapper  | 2021/08/15 10:21:36 | Startup failed: Timed out waiting for a signal from the JVM.
ERROR  | wrapper  | 2021/08/15 10:21:36 | JVM did not exit on request, terminated

Description:
the newly installed MYCAT starts with MYCAT start and directly reports an error. The environment is CentOS 7.6. I don’t have this error on CentOS 7.5 for the same operation. I’m blinded. I read it on the Internet. At first, I said that the memory of the virtual machine was too small. After trying, I still reported this error.

The solution is as follows:

[root@db02 conf]# vim wrapper.conf  #Modify the startup configuration file with the following parameter
wrapper.startup.timeout=300
[root@db02 logs]# vim /etc/hosts #Modify the correspondence between hostname and IP address
10.0.0.52 db02






[root@db02 conf]# mycat start # Restart it (may take more than a few seconds)

[root@db02 logs]# tailf wrapper.log # Check the logs again and see that it started successfully
INFO   | jvm 1    | 2021/08/15 10:24:24 | OpenJDK 64-Bit Server VM warning: ignoring option MaxPermSize=64M; support was removed in 8.0
INFO   | jvm 1    | 2021/08/15 10:24:50 | Wrapper (Version 3.2.3) http://wrapper.tanukisoftware.org
INFO   | jvm 1    | 2021/08/15 10:24:50 |   Copyright 1999-2006 Tanuki Software, Inc.  All Rights Reserved.
INFO   | jvm 1    | 2021/08/15 10:24:50 | 
INFO   | jvm 1    | 2021/08/15 10:25:16 | MyCAT Server startup successfully. see logs in logs/mycat.log

[root@db02 logs]# netstat -anptul |grep java   #Check port is also up
tcp        0      0 127.0.0.1:32000         0.0.0.0:*               LISTEN      8217/java           
tcp6       0      0 :::9066                 :::*                    LISTEN      8217/java           
tcp6       0      0 :::10579                :::*                    LISTEN      8217/java           
tcp6       0      0 :::1984                 :::*                    LISTEN      8217/java           
tcp6       0      0 :::8066                 :::*                    LISTEN      8217/java           
tcp6       0      0 :::10310                :::*                    LISTEN      8217/java           
tcp6       0      0 127.0.0.1:31000         127.0.0.1:32000         ESTABLISHED 8217/java