Oracle Background Processes

[s_radhak]

When I log on to the Database using DBA Studio I see 12 active sessions . 1 is for DBA Studio and 11 of them are the background processes.

What are these background processes. Can u please list them?

Is their any significance for all the background processes to have the serial# as 1? What if the serial# for background processes 7 thro' 10 (and these processes do not specify any OS info or username or the program which it is using) are something other than 1? Is there something wrong with the database?

Thank you.

[padmam]

Hi, 4th May 2001 20:04 hrs chennai

Normally 5 BG process or 6 if Archiving.

In addition to that you have Java runtime environment process running.

If i am wrong please correct me.(JRE).

I also saw v$process but it shows all as ORACLE.EXE's

20:01:18 SQL> select sid,USERNAME,PROCESS,PROGRAM from v$session;

SID USERNAME PROCESS PROGRAM
---------- ------------------------------ --------- ---------------
1 2356 ORACLE.EXE
2 548 ORACLE.EXE
3 2300 ORACLE.EXE
4 1960 ORACLE.EXE
5 1052 ORACLE.EXE
6 884 ORACLE.EXE
7
8
9
10
11 SYS 2652:2304 SQLPLUSW.EXE

SID USERNAME PROCESS PROGRAM
---------- ------------------------------ --------- ---------------
12 SYSMAN 812:1924 jre.exe
13 SYSMAN 812:2608 jre.exe
14 SYSMAN 812:1924 jre.exe
15 SYSMAN 812:1924 jre.exe
16 SYSMAN 812:1924 jre.exe
17 SYSMAN 812:1924 jre.exe
18 SYSMAN 812:1924 jre.exe
19 SYSMAN 812:1924 jre.exe

Cheers

Padmam

[sambavan]

PMON process cleanup
TRWR trace writer process
LMON lkmgr monitor
LMD0 lkmgr daemon 0
DBW0 db writer process 0
ARC0 Archival Process 0
LGWR Redo etc.
LCK0 Lock Process 0
BSP0 Buffer Server Process 0
CKPT checkpoint
SMON System Monitor Process
RECO distributed recovery
EMN0 Event Monitor Process 0
SNP0 Job Queue Process 0
QMN0 AQ Time Manager Process 0
S001 MTS server threads process 0
D001 MTS dispatcher thread process 0

I might have missed some. But these are the some of the pimary processes that you would see when an instance were to start.


Sam

[s_radhak]

Padmam,

In the list u see processes 7 thro 10 without any program associated with it. Is this always the case?

Sam,

U mean these are some of the processes that start when a "database" is started or an when an "instance" is started???

[padmam]

Hi, 4th May 2001 21:02 hrs chennai

I see them as user process i am not much sure like

21:01:08 SQL> /

SID TYPE PROCESS PROGRAM
---------- ---------- --------- --------------
1 BACKGROUND 2356 ORACLE.EXE
2 BACKGROUND 548 ORACLE.EXE
3 BACKGROUND 2300 ORACLE.EXE
4 BACKGROUND 1960 ORACLE.EXE
5 BACKGROUND 1052 ORACLE.EXE
6 BACKGROUND 884 ORACLE.EXE
7 USER
8 USER
9 USER
10 USER
11 USER 2652:2304 SQLPLUSW.EXE

Now after i stopped the OMServer and data gatherer the list has trimmed to 11 so all JRE is created during the above 2 services.

For 7-10 it shows as user process i saw in the process list of task manager it shows

ORADIME.EXE ,owastsvr.exe,TNSLNR.EXE,Launch.exe are running so probably this should be that ....This are oracle exe i think identified as a process in v$session.I also checked whether any other oracle exe are running other than the above nothing.

By Checking all the oracle Exe's available in Bin dir.

In your condition of DBA studio please check it what process running from Task manager may be some more oracle exe'd requ for that.

Expecting your feedback on this.

If i am wrong please correct me.

Of course the SQLPLUSW.EXE you know the session i work on.(user process).

Cheers

Padmam

[Edited by padmam on 05-04-2001 at 12:12 PM]

[sambavan]

Yes, that is correct. The sadest part on Bills product is it would just say that it was background process. I so far I haven't found a way to associate those backgroud proceess to the process names. In any Unix or Linux, you can see the processes with the names and they get tagged with the SID. As a result you can easily associate the procees to the operation they perform.


Now, if you have the MTS setup say that you have set 2 dispatchers and 10 servers to start. YOu would see an increase in the bg processes. If you are in the unix env, then you would see ora_s000_SID,... ora_s009_SID, and ora_d000_SID, .. ora_d002_SID and so on. IF you have more than one archive destination, then your archiver process would be those count. On the other hand if you have a dedicated server setup and then you would see an increase in the db writer processes.


I hope this would help you to undestand these better.

Sam