Re: Blocking sessions related to client process
- From: Niall Litchfield <niall.litchfield@xxxxxxxxx>
- To: tanel@xxxxxxxxxx
- Date: Wed, 29 Sep 2010 16:03:45 +0100
Didn't know about that Magic Number - thanks Tanel. I believe that
client_info can be set using JDBC thin though right so maybe the application
developers could help out if they are available. I can't imagine this would
be the only time knowing who is doing what is helpful - not sure how that
works with connection pools either..
On Wed, Sep 29, 2010 at 2:07 PM, Tanel Poder <tanel@xxxxxxxxxx> wrote:
> JDBC Thin drivers always set the client process to 1234 as thin drivers,
> being fully contained within JVM, don't have a way to find out the PID of
> the JVM process itself. Someone JDBC developer in the java world figured
> that a good number for specifying "unknown" value is 1234, instead of 0 or
> -1.
>
> In such case you can identify the SPID of the database process, run lsof
> (or pfiles if on solaris) on the process to see to which IP/port combo it's
> talking to. Then log on to that IP and run lsof there to see which process
> uses that peer port... this won't work well with connection pools though...
>
>
> --
> Tanel Poder
> http://tech.e2sn.com
> http://blog.tanelpoder.com
>
>
>
>
> On Wed, Sep 29, 2010 at 3:06 PM, <Joel.Patterson@xxxxxxxxxxx> wrote:
>
>> Any help would be appreciated.
>>
>> I respect and appreciate every ones time. If this is considered to basic
>> a question, then perhaps pointing me to the right place would be helpful
>> because I can’t find the right docs or get to the bottom of this. It
>> should be more of a clarification as I have been doing this a long time,
>> so I figure I’m missing something.
>>
>> The person asking me was using EM, and saw 4 blocking locks, (in the
>> blocking sessions section), and in the client section he sees OS process
>> 1234 but cannot grep for this process on the client machine. He wants to
>> go from the blocking sessions in the database (jaxlawdw), and link to the
>> corresponding process on the client machine.
>>
>> The person says that it is always client process 1234 as indicated in
>> enterprise manager ‘blocking sessions’ , ‘session details’, ‘Client’, ‘OS
>> Process ID’. The person believes it is a ‘fake’ or phantom process.
>>
>> How do I help, as I may not be giving the correct explanation, else we
>> should see the process on the client machine?
>>
>> Example of first row when combining v$session and v$process, shows s.sid
>> 486, p.pid 47, p.spid 8105, and s.process 1234.
>>
>> Note when querying these two tables for s.process 1234 it returned 58
>> rows, (but this was done then next day and not live when the blocking
>> sessions where happening).
>>
>> Session Process p.pid p.spid Session
>>
>> SID Serial# Serial# Ora ProcID OS ProcID Process Session
>> Username OS Username STATUS MACHINE Process Program
>>
>> ------ ------- ------- ---------- ------------ ------------
>> -------------------- ------------ -------- --------- ----------------------
>>
>> 486 36738 136 47 8105 1234
>> GENTRAN b2badmin INACTIVE jaxb2bprd oracleGISPROD@jaxlawdw
>>
>> Joel Patterson
>> Database Administrator
>> 904 727-2546
>>
>>
>
--
Niall Litchfield
Oracle DBA
http://www.orawin.info
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