Kernel profile in SAP HANA

Activity 1:


The following statement starts profiling for the SYSTEM user, sets a memory limit of 1 GB, and sets a sampling interval of 2 milliseconds.



ALTER SYSTEM START KERNEL PROFILER USER SYSTEM MEMORY LIMIT 1073741824 SAMPLING INTERVAL 2; 

Activity 2:

The following statement stops profiling, saves the data for the specified call stacks into the trace directory, and then frees the memory that was used for the profiling data.

ALTER SYSTEM SAVE KERNEL PROFILER FOR CALLSTACK 'Execution::JobExecWatchdog::run','System::ProcessorInfo::getCurrentProcessorIndex' INTO CPU FILE 'cpu.dot' WAIT FILE 'wait.dot';

Activity 3:

ALTER SYSTEM STOP KERNEL PROFILER

Stops the Kernel Profiler (but does not free up the allocated memory).

<stop_profiler> ::= STOP KERNEL PROFILER [ <location> ]


Activity 4:

The following statement clears all previously collected Kernel Profiler data.


ALTER SYSTEM CLEAR KERNEL PROFILER;