The maxThreads attribute determines the maximum number of request processing threads to be created by the HTTP Connector, which therefore determines the maximum number of simultaneous requests that can be handled. If you are receiving the "Please increase maxThreads" error, it means that the connector is unable to create a new thread to handle a new request because the maximum number of threads has been reached.
To increase the value of maxThreads, you will need to edit the server.xml file, which is typically located in the conf directory of your Tomcat installation. Locate the <Connector> element that corresponds to the HTTP connector, and set the maxThreads attribute to the desired value. For example:
<Connector port="8080" protocol="HTTP/1.1"
connectionTimeout="20000"
redirectPort="8443"
maxThreads="200" />
After modifying the server.xml file, restart Tomcat for the changes to take effect.