You can restrict the number of users accessing a service by updating the tomcat.conf file.
Open Identity Server’s tomcat.conf and add the following parameter:
JAVA_OPTS="${JAVA_OPTS} -Dcom.novell.oauth.threshold.maxrequestsallowed=<number of requests>"
For example, JAVA_OPTS="${JAVA_OPTS} -Dcom.novell.oauth.threshold.maxrequestsallowed=10". It will not allow more than 10 requests per second.
For information about how to open and modify a file, see Modifying Configurations.