Re: MpxTestDaemon

From: Mladen Gogala <gogala.mladen_at_gmail.com>
Date: Wed, 21 Oct 2020 13:36:40 -0400
Message-ID: <1fba2e60-d2a9-c678-6609-5b3b718f5212_at_gmail.com>

Hi Jared,

If that is Linux, go to /proc/<pid>/fd and see what files does the process have open. Also, find the xeceutable and do ldd on it. That will show you the libraries. That looks something like this:

root_at_umajor:/home/mgogala# _*ldd /usr/bin/python3*_

     linux-vdso.so.1 (0x00007fff9458a000)
     libc.so.6 => /lib/x86_64-linux-gnu/libc.so.6 (0x00007f8c53013000)
     libpthread.so.0 => /lib/x86_64-linux-gnu/libpthread.so.0

(0x00007f8c52ff0000)

     libdl.so.2 => /lib/x86_64-linux-gnu/libdl.so.2 (0x00007f8c52fea000)
     libutil.so.1 => /lib/x86_64-linux-gnu/libutil.so.1 (0x00007f8c52fe5000)
     libm.so.6 => /lib/x86_64-linux-gnu/libm.so.6 (0x00007f8c52e96000)
     libexpat.so.1 => /lib/x86_64-linux-gnu/libexpat.so.1

(0x00007f8c52e68000)
libz.so.1 => /lib/x86_64-linux-gnu/libz.so.1 (0x00007f8c52e4a000) /lib64/ld-linux-x86-64.so.2 (0x00007f8c53230000)

If the process uses EMC libraries, you know who to ask. As for the /proc trick, it goes like this:

root_at_umajor:/proc/39972# cd /proc/39972/fd root_at_umajor:/proc/39972/fd# ls -l
total 0

lrwx------ 1 root root 64 Oct 21 12:50 0 -> /dev/pts/0
lrwx------ 1 root root 64 Oct 21 12:50 1 -> /dev/pts/0
lrwx------ 1 root root 64 Oct 21 12:50 2 -> /dev/pts/0
lrwx------ 1 root root 64 Oct 21 13:22 255 -> /dev/pts/0

root_at_umajor:/proc/39972/fd# ps -fp 39972 UID PID PPID C STIME TTY TIME CMD root 39972 39868 0 12:50 pts/0 00:00:00 bash root_at_umajor:/proc/39972/fd#

This is bash, it holds the terminal. You can also check /proc/<pid>/map_files. It gives you more details than ldd. If you are lucky, the executable will have some symbols, but mostly they do not. Symbols are usually stripped off:

root_at_umajor:/proc/39972/map_files# nm /bin/bash nm: /bin/bash: no symbols

Instead of nm, you can use objdump --syms -T /bin/bash The result looks like this:

bin/bash: file format elf64-x86-64

SYMBOL TABLE:
no symbols

DYNAMIC SYMBOL TABLE:

0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 endgrent
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.3

__ctype_toupper_loc

0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 iswlower
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 sigprocmask
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.3.4 __snprintf_chk
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 free
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 getservent
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 wcscmp
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 putchar
0000000000000000      DF *UND*  0000000000000000

NCURSES6_TINFO_5.0.19991023 tputs

0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 strcasecmp
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 localtime
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 mblen
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.3.4 __vfprintf_chk
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 abort
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5

__errno_location

0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 strncpy
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 strncmp
0000000000000000  w   D  *UND* 0000000000000000

_ITM_deregisterTMCloneTable

0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 wcscoll
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 strcpy
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 getgrent
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 iconv
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 puts
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 ferror
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 qsort
0000000000000000      DF *UND*  0000000000000000 GLIBC_2.2.5 isatty

The names should allow you to guess the purpose. Should all else fail, there is always the good, old "strings" command. Of course, you can use strace and ltrace to see what is the process doing. That might give you some idea about what it is.

Regards

On 10/20/20 6:00 PM, Jared Still wrote:
> Dear list:
>
> I am investigating a process 'MpxTestDaemon' on a Linux server (RedHat
> 6.9 as I recall).
>
> This server is running Oracle 12.1, and has 1.5T of RAM.
>
> It is a standalone server, not RAC.
>
> There are some anomalous things occurring with this process.
>
> For instance, at times pidstat reports impossible numbers of minflt/s
> (mem faults not requiring disk access) being performed: approx 1.85 *
> 10e18
>
> Right now though all I am asking is this:
>
> Does anyone know what this process is?
>
> Neither Oracle nor the Google have anything helpful.
>
> In Oracle's case, no references at all.
>
> In the meantime, I shall see if I can find out what it is doing.
>
> Thanks.
>
> Jared Still
> Certifiable Oracle DBA and Part Time Perl Evangelist
> Principal Consultant at Pythian
> Oracle ACE Alumni
> Pythian Blog http://www.pythian.com/blog/author/still/
> Github: https://github.com/jkstill
>
>

-- 
Mladen Gogala
Database Consultant
Tel: (347) 321-1217


--
http://www.freelists.org/webpage/oracle-l

Received on Wed Oct 21 2020 - 19:36:40 CEST

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