Yesterday I have got this issue. Just replace this from another server.
Replace this, it works for me.
Timeout 150
KeepAlive On
MaxKeepAliveRequests 100
KeepAliveTimeout 15
<IfModule prefork.c>
StartServers 2
MinSpareServers 63
MaxSpareServers 127
ServerLimit 127
<IfVersion >= 2.4>
MaxRequestWorkers 127
MaxConnectionsPerChild 4000
</IfVersion>
<IfVersion < 2.4>
MaxClients 127
MaxRequestsPerChild 4000
</IfVersion>
MaxMemFree 2
SendBufferSize 65536
ReceiveBufferSize 65536
</IfModule>
<IfModule itk.c>
StartServers 2
MinSpareServers 63
MaxSpareServers 127
ServerLimit 127
<IfVersion >= 2.4>
MaxRequestWorkers 127
MaxConnectionsPerChild 4000
</IfVersion>
<IfVersion < 2.4>
MaxClients 127
MaxRequestsPerChild 4000
</IfVersion>
MaxMemFree 2
SendBufferSize 65536
ReceiveBufferSize 65536
</IfModule>
<IfModule worker.c>
StartServers 2
MinSpareThreads 54
MaxSpareThreads 109
ThreadsPerChild 25
ServerLimit 109
<IfVersion >= 2.4>
MaxRequestWorkers 2725
MaxConnectionsPerChild 0
</IfVersion>
<IfVersion < 2.4>
MaxClients 2725
MaxRequestsPerChild 0
</IfVersion>
SendBufferSize 65536
ReceiveBufferSize 65536
</IfModule>
<IfModule event.c>
StartServers 2
MinSpareThreads 54
MaxSpareThreads 109
ThreadsPerChild 25
ServerLimit 109
MaxRequestsPerChild 0
<IfVersion >= 2.4>
MaxRequestWorkers 2725
MaxConnectionsPerChild 0
</IfVersion>
<IfVersion < 2.4>
MaxClients 2725
MaxRequestsPerChild 0
</IfVersion>
SendBufferSize 65536
ReceiveBufferSize 65536
</IfModule>
Include /opt/configs/apache/conf/defaults/*.conf
Include /opt/configs/apache/conf/domains/*.conf
### selected: high ###