Gets server performance statistics depending on the mode. This works on all platforms.
perf_monitor Returns internal data in a structure. Returned data includes: InstanceName, PageHits, ReqQueued, DBHits, ReqRunning, ReqTimedOut, BytesIn, BytesOut, AvgQueueTime, AvgReqTime, AvgDBTime.
simple_load Returns an integer value that is computed from the state of the server's internal queues.
prev_req_time Returns the time, in milliseconds, that it took the server to process the previous request.
avg_req_time Returns the average time, in milliseconds, that it takes the server to process a request.