IDS Forum

Re: A Sleeping Thread - Or is it?

Posted By: Michael Mueller
Date: Friday, 27 June 2003, at 3:54 a.m.

In Response To: Re: A Sleeping Thread - Or is it? (Madison Pruet )

Kevin,

Yes, it's probably undocumented. Its main purpose is to enable the
collection of thread run statistics data, output using "onstat -g wst".
The changed "onstat -g ath" output is only a side effect. This is what
it does:

Every time a thread changes scheduler status (ready, running, waiting
for mutexes, conditions, etc.) the os is called to get the microsecond
time. (This is where the cpu overhead comes from.) The time spent in
each state is kept in shared memory. This information is output using
onstat -g wst.

Michael

Kevin Struckhoff wrote:
> Michael,
>
> Is WSTATS an undocumented parameter? I couldn't find it anywhere in the
> docs.
>
> -----Original Message-----
> From: Michael Mueller [mailto:michael.mueller01@kay-mueller.de]
> Sent: Thursday, June 26, 2003 12:18 PM
> To: Kevin Struckhoff
> Cc: Madison Pruet; ids@iiug.org
> Subject: Re: A Sleeping Thread - Or is it? [1424]
>
>
> One way of finding out a little more about the wait reason is by
> specifying
>
> WSTATS 1
>
> in the server's onconfig file. For a thread waiting for io you will then
>
> see something like this:
>
> Threads:
> tid tcb rstcb prty status vp-class name
> 27 11145d70 10c48418 2 yield aiowait 1cpu sqlexec
>
> Some of the other things shown are "yield bufwait" and "yield lockwait".
>
> But WSTATS will use up a little more cpu time and therefore should not
> be set in heavily loaded systems.
>
> Michael
>
>
> Madison Pruet wrote:
>
>>Because it's waiting for a locked resource and you have lock mode set
>>to wait? Either that, or the thread is waiting for an IO completion
>>in the scan.
>>
>>
>>M.P.
>>
>>
>>
>
>
>> "Kevin Struc...."
>
>
>> <Kevin_Struckhoff@yamaha To:
>
> ids@iiug.org
>
>> -motor.com> cc:
>
>
>> Sent by: Subject: A
>
> Sleeping Thread - Or is it? [1422]
>
>> forum.subscriber@iiug.or
>
>
>> g
>
>
>
>
>> 06/25/2003 03:25 PM
>
>
>
>
>>
>>
>>
>>I am running an update statement on a single-cpu configured HP box w/
>>IDS 9.30FC2. The thread says that it is sleeping (Forever), yet the
>>the update statement is working it's way thru the table. It wakes up
>>once in a while, says it's running, then goes back to sleep. There is
>>currently 2 other select statements running. Is there a way to wake up
>
>
>>the thread and keep it awake? If it is sleeping, why is the table
>>still being updated?
>>
>>---- top of onstat -g ses output
>>---------------------------------------------------------
>>
>>Informix Dynamic Server Version 9.30.FC2 -- On-Line -- Up 19:49:50
>>-- 941084 Kbytes
>>
>>session #RSAM total used
>>id user tty pid hostname threads memory
>>memory
>>205 dw_admin ta 7055 pddwhdb1 1 208896
>
> 201744
>
>>tid name rstcb flags curstk
>
> status
>
>>365 sqlexec c00000002dc88c88 B--PR-- 24144 sleeping(Forever)
>>
>>----------------------------------------------------------------------
>>--
>>-------------------------------
>>
>>Thanks,
>>
>>Kevin Struckhoff
>>Data Warehouse Consultant
>>Kevin_Struckhoff@yamaha-motor.com
>>
>>
>>
>>
>>
>>
>>
>>
>>
>
>
>


--

=== Michael Mueller ==================
Tel. + 49 8171 63600
Fax. + 49 8171 63615
Web: http://www.mm.kay-mueller.de
http://www.planets.kay-mueller.de
======================================

Messages In This Thread

• A Sleeping Thread - Or is it?
  Kevin Struckhoff -- Wednesday, 25 June 2003, at 6:25 p.m.
  • RE: A Sleeping Thread - Or is it?
    Murray Wood \(IList\) -- Wednesday, 25 June 2003, at 7:31 p.m.
  • Re: A Sleeping Thread - Or is it?
    Madison Pruet -- Wednesday, 25 June 2003, at 7:56 p.m.
    • Re: A Sleeping Thread - Or is it?
      Michael Mueller -- Friday, 27 June 2003, at 3:54 a.m.

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