The namespace debug
gives you access to several non-standard RPC methods, which will allow you to inspect, debug and set certain debugging flags at run time.
​debug_backtraceAt​
​debug_setVMLogTarget​
​debug_verbosity​
​debug_vmodule​
​debug_blockProfile​
​debug_cpuProfile​
​debug_isPProfRunning​
​debug_startCPUProfile​
​debug_stopCPUProfile​
​debug_startPProf​
​debug_stopPProf​
​debug_writeBlockProfile​
​debug_writeMemProfile​
​debug_goTrace​
​debug_startGoTrace​
​debug_stopGoTrace​
​debug_freeOSMemory​
​debug_gcStats​
​debug_memStats​
​debug_metrics​
​debug_setGCPercent​
​debug_stacks​
​debug_traceBadBlock​
​debug_traceBlock​
​debug_traceBlockByHash​
​debug_traceBlockByNumber​
​debug_traceBlockFromFile​
​debug_traceTransaction​
​Tracing Options​
​JavaScript-based Tracing​
​Standard Tracing Options​
​debug_dumpBlock​
​debug_getBlockRlp​
​debug_preimage​
​debug_printBlock​
​debug_setHead​