I got an error like this
server ~]# grep MaxRequestWorkers /usr/local/apache/logs/error_log | grep -v 'not at'
[Sun Nov 29 17:31:59.460559 2020] [mpm_prefork:error] [pid 1537] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Tue Dec 15 23:41:01.757848 2020] [mpm_prefork:error] [pid 1355] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Fri Mar 19 10:28:21.778787 2021] [mpm_prefork:error] [pid 19278] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Sun Jun 20 13:22:13.941315 2021] [mpm_prefork:error] [pid 1523] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Thu Jul 01 18:08:08.357847 2021] [mpm_prefork:error] [pid 5316] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
[Mon Sep 13 12:27:30.214507 2021] [mpm_prefork:error] [pid 1491] AH00161: server reached MaxRequestWorkers setting, consider raising the MaxRequestWorkers setting
I increase the MaxRequestWorkers 150 to 500
server limit : 256 to 1024