Re: High CPU utilization

Hi Mladen,

> How precisely would you use profiler to answer the question of which instance is hogging CPU and memory? Can you please elucidate me?

Krishna wanted to know which instances/databases are utilizing the CPU - so you run xcapture (from the 0xtools software suite) as a daemon and you get a CSV file that contains all OS processes which are running on CPU or waiting on something for every second.

As the Oracle instance name is included in the OS process name you finally just grep the CSV file(s) for status "R" and group by the Oracle instance name. The 0xtools website also has an example with Oracle and also an example for aggregating the CSV data, e.g.

$ head 2020-10-16.21.csv
TS,PID,TID,USERNAME,ST,COMMAND,SYSCALL,WCHAN,EXE,CMDLINE,KSTACK ...
2020-10-16 21:00:02.075,16762,16762,oracle,R,(ora_m000_lin19c),[running],0,oracle,ora_m000_LIN19C,->do_blockdev_direct_IO()->dio_complete() ...

$ cat 2020-10-13.01.csv | awk -F, '{ printf("%2s %-20s %-20s %s\n",$5,$4,$7,$10) }' | sort | uniq -c | sort -nbr | head -20 ...

     51 R oracle [running] oracleLIN19C ...

Of course Krishna could also do this on his own by reading the /proc filesystem but why doing it by yourself when there is already a great and free software suite for that.

Best Regards
Stefan Koehler

Independent Oracle performance consultant and researcher Website: www.soocs.de
Twitter: _at_OracleSK

> Mladen Gogala <gogala.mladen_at_gmail.com> hat am 17.03.2024 19:26 CET geschrieben:
>
> Hi Stefan,
> I might have misunderstood the 0x.tools. My understanding was that is can be used for profiling sessions and doing the event analysis of Oracle performance problems. It's a profiler, similar in purpose to gprof. How precisely would you use profiler to answer the question of which instance is hogging CPU and memory? Can you please elucidate me?
> Regards
> --
> Mladen Gogala
> Database SME
> https://dbwhisperer.wordpress.com
>

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