Yum install error: Another app is currently holding the yum lock

When yum-y install gcc * gcc-c ++ * autoconf * automake * zlib * libxml * ncurses-devel * libmcrypt * libtool * On CentOS, an error occurs:
 
1) What is going on? According to the prompt, an update is already running in the system process. View in the process: ps-ef | grep update

2) kill the process to kill the process. After killing the process, the error persists. In the original/var/run directory, there is also the yum process ID, which needs to be forcibly deleted:
 
3) restart the yum Update Service as follows:

4) Restart yum-y install gcc * gcc-c ++ * autoconf * automake * zlib * libxml * ncurses-devel * libmcrypt * libtool *.

This article is from the second dwelling blog