1. A data processing system for system monitoring in an information technology (IT) system, the data processing system comprising: a client monitoring module configured to monitor a performance parameter of a client of the IT system; a first determining module configured to determine, based on the performance parameter of the client, whether to monitor a service endpoint directly called by the client; a service endpoint locating module configured to, in response to a determination to monitor the service endpoint directly called by the client, locate the service endpoint to be monitored, wherein the service endpoint locating module is configured to locate the service endpoint by: determining an IP address and a port number of the service endpoint directly called by the client; and obtaining application information regarding an application running on the service endpoint based on the IP address and the port number, wherein the application information includes at least a name and a version number of the application; and a service endpoint monitoring module configured to monitor a performance parameter of the service endpoint in response to a determination to monitor the service endpoint, wherein the service endpoint monitoring module is configured to monitor the performance parameter of the service endpoint by: determining, based on the obtained application information, whether a monitor agent corresponding to the application has been deployed on the service endpoint; in response to determining that the monitor agent has not been deployed on the service endpoint, selecting, from among a plurality of monitor agents, the monitor agent corresponding to the application based on the name and version number of the application and a monitor agent mapping data structure, and deploying the monitor agent on the service endpoint; activating the monitor agent on the service endpoint and monitoring the performance parameter through the monitor agent deployed on the service endpoint.