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Home -> Community -> Mailing Lists -> Oracle-L -> RE: systemstate dump
cool, so it was DLM and intermachine networking.
groovy baby.
-----Original Message-----
From: Mladen Gogala [mailto:mgogala_at_adelphia.net]
Sent: Wed 4/28/2004 4:52 AM
To: oracle-l_at_freelists.org
Cc:
Subject: Re: systemstate dump
I only now saw this post. Sorry for being late. There is an oracle bug in 8i with DLM. To make the long story short, a global enqueue "loses" owner, and, consequently, cannot be relased. That causes all kinds of beautiful events. Here is what I'm talking about and what Mogens would call CTNOM:
Article-ID: <Note:157766.1> Circulation: PUBLISHED (EXTERNAL) Folder: server.HA.RAC Topic: Performance, Tuning and Hanging Issues Title: Sessions Wait Forever for 'global cache cr request' Wait Event in OPS or RAC Document-Type: PROBLEM Impact: MEDIUM Skill-Level: NOVICE Server-Version: 08.01 to 09.00 Updated-Date: 18-FEB-2003 11:35:45 References: <BUG:1916409> Shared-Refs: Authors: MPOLASKI.US Attachments: NONE Content-Type: TEXT/PLAIN Products: 5/RDBMS; Platforms: GENERIC;
Problem Description
Sessions hang indefinately in an OPS environment. Session(s) wait forever
for
the 'global cache cr request' wait event. Other sessions could end up
waiting
for the 'buffer busy due to global cache' or 'global cache lock busy' wait
events.
Solution Description
This is a known issue (Bug 1916409). To immediately resolve the hang all instances will have to be restarted.
To permanently correct the problem upgrade to a fixed release or apply necessary patches available on Metalink.
Fixed Versions:
Explanation
Due to Bug 1916409 a PCM lock with the expired timeout might not be ever cancelled.
Possible Symptoms:
select sid, event, seq#, seconds_in_wait from gv$session_wait where event like 'global cache%';
PCM lock has On_timer_q? : Y and a negative timeout value. Example:
----------lock-------------------------- lock version : 10165 Owner node : 0 grant_level : KJUSERNL <-- Granted in Null Mode req_level : KJUSERPR <-- Requesting Protected Read bast_level : KJUSERNL notify_func : 0 resp : 0x99dd5174 procp : 0x9866e644 remote_lockp : 0x9916d114 pid : 5012 proc version : 418 oprocp : 0x9866e644 opid : 5012 gid : 1 xid : 0 0 crstate : 5 dd_time : 0.0 secs dd_count : 0 timeout : -26786.0 secs <-- Negative timeout value On_timer_q? : Y <-- On Timer Queue On_dd_q? : N lock_state : KJUSEROPENING Open Options : KJUSERPERSISTENT Convert options : KJUSERGETVALUE History : 0x231726cd Msg_Seq : 0x0
References
Bug 1916409
Additional Search Words
OPS RAC Hang Global Cache cr request buffer busy timeout
@ OPS RAC Hang Global Cache cr request buffer busy timeout @ OPS RAC Hang Global Cache cr request buffer busy timeout @ OPS RAC Hang Global Cache cr request buffer busy timeout
So, please, check the note on Metalink.
On 04/28/2004 12:32:01 AM, "Mohan, Ross" wrote:
> here is a bleary-eyed and largely uninformed comment. > > I once saw an OPS cluster screw up badly due to inter machine networking > considerations. > > I would look at the DLM latching, intermachine networking word size, > latencies, > and collisions. > > I think you are digging a deep hole, when what you need is an effective > tunnel. > > Bon Chance > -----Original Message----- > From: Henry Poras [mailto:hporas_at_comcast.net <mailto:hporas_at_comcast.net> ] > Sent: Wed 4/28/2004 2:08 AM > To: oracle-l_at_freelists.org > Cc: > Subject: systemstate dump > > > > We have an Oracle/PeopleSoft implementation (8.1.7 on Solaris) which on> occasion stops any new logons from happening. Performance for existing > sessions is so slow as to be non-existent. This is a two instance OPS system
> with the second instance existing solely for failover. The data I have > gathered comes from three sources:statspack snapshots at 15 minute > intervals, some 10046 traces (level 12) which have since been deleted, > systemstate dump. > > >From statspack, I compared the 15 (closer to 20) minute snapshot wherethe
> > -CPU time almost unchanged > -a huge change in the Total Wait Time (cs) for the following events (the > number of waits were all within an order of 2 of each other except forlatch
> free which jumped from 200 to 150,000). > > NAME TIME-initial (cs)TIME-final
> (cs) > latch free 200 > 2,800,000 > enqueue 900 > 280,000 > global cache lock busy 8,200 30,000 > library cache pin 500 18,000 > row cache lock 600 15,000 > library cache lock 600 8,000 > DFS lock handle 30 5,000 > PX Deq: Execution Msg -- 5,000 > > -latch sleeps skyrocketed for library cache, shared pool, and row cache> objects with many having at least 4 sleeps. The 'dlm resource hash list' > latch had about the same number of sleeps, but the number of gets increased
> by ~x10. > > For the 10046 traces (taken a few weeks ago) I had a chance to lookthrough
> a few of the multitude before they were deleted. > > -Lots of latch free:library cache, shared pool, and row cache objectwaits.
> children). > > -Increase in library cache lock and library cache pin. These are pointingto
> lock enqueue. > > My working model is that the latch free (library cache) waits are asymptom.
> Get a latch. Someone else wants it. Latch contention. Latch contention > builds. Spin, sleep, another process, more latch contention, ... Take a > systemstate dump to see what is happening. > > >From systemstate dump. (I thought I once saw a document on metalink tohelp
> the process which holds the shared pool latch follows: > > PROCESS 23: > ---------------------------------------- > SO: d9523624, type: 1, owner: 0, pt: 0, flag: INIT/-/-/0x00 > (process) Oracle pid=23, calls cur/top: d960d7d4/d960d7d4, flag: (0) - > int error: 0, call error: 0, sess error: 0, txn error 0 > (post info) last post received: 3648316968 0 1 > last post received-location: kslfre > last process to post me: d9522cd0 4 0 > last post sent: 2147544044 0 1 > last post sent-location: kslfre > last process posted by me: d9525220 41 0 > (latch info) wait_event=0 bits=90 > holding 8000ebec shared pool level=7 > Location from where latch is held: kghfrunp: alloc: clatch nowait: > Context saved from call: 0 > state=busy > holding 8000c114 row cache objects level=4 > Location from where latch is held: kghfrunp: clatch: nowait: > Context saved from call: 0 > state=busy > Process Group: DEFAULT, pseudo proc: d955952c > O/S info: user: oracle, term: UNKNOWN, ospid: 5345 > OSD pid info: 5345 > ---------------------------------------- > SO: d95991a0, type: 3, owner: d9523624, pt: 0, flag: INIT/-/-/0x00 > (session) trans: 0, creator: d9523624, flag: (41) USR/- BSY/-/-/-/-/- > DID: 0000-0000-00000000, short-term DID: 0000-0000-00000000 > txn branch: 0 > oct: 47, prv: 0, user: 20/SYSADM > O/S info: user: dp943, term: PHSPSPAPP8, ospid: 2028:3424, machine: > PARTNERS\PHSPSPAPP8 > program: PSAPPSRV.exe > client info: ,dp943,PHSPSPAPP8,,PSAPPSRV.exe, > last wait for 'latch free' blocking sess=0x0 seq=14093 wait_time=-1 > address=d974e628, number=6a, tries=1 > ---------------------------------------- > SO: d97c6674, type: 36, owner: d95991a0, flag: INIT/-/-/0x00 > LIBRARY OBJECT PIN: pin=d97c6674 handle=da02bb1c mode=X lock=d97d5c84 > user=d95991a0 session=d95991a0 count=0 mask=007d savepoint=68 > flags=[00] > ---------------------------------------- > SO: d97d5c84, type: 35, owner: d95991a0, flag: INIT/-/-/0x00 > LIBRARY OBJECT LOCK: lock=d97d5c84 handle=da02bb1c mode=N > call pin=0 session pin=d97c6674 > user=d95991a0 session=d95991a0 count=1 flags=PNS/[08] savepoint=68 > LIBRARY OBJECT HANDLE: handle=da02bb1c > namespace=CRSR flags=RON/KGHP/PN0/[10010000] > kkkk-dddd-llll=0000-0000-0000 lock=N pin=X latch=2 > lwt=da02bb34[da02bb34,da02bb34] ltm=da02bb3c[da02bb3c,da02bb3c] > pwt=da02bb4c[da02bb4c,da02bb4c] ptm=da02bba4[da02bba4,da02bba4] > ref=da02bb24[cac6f6d8,cac6f6d8] lnd=da02bbb0[da02bbb0,da02bbb0] > LIBRARY OBJECT: object=dadfc344 > type=CRSR flags=EXS/BCM[0001] pflags=NST [101] status=VALD load=0 > DEPENDENCIES: count=4 size=16 > ACCESSES: count=1 size=16 > TRANSLATIONS: count=1 size=16 > DATA BLOCKS: > data# heap pointer status pins change > ----- -------- -------- ------ ---- ------ > 0 c9cee16c dadfc1b4 I/P/A 0 NONE > 2 dadfc3d8 c9c4bb3c I/P/A 1 NONE > 3 dadfc438 0 -/P/- 1 NONE > 4 dadfc498 cf49aef0 I/P/A 1 NONE > 5 dadfc104 0 -/P/- 1 NONE > 6 dadfc164 cb43e3e4 I/P/A 1 NONE > ---------------------------------------- > SO: d97cc9cc, type: 35, owner: d95991a0, flag: INIT/-/-/0x00 > LIBRARY OBJECT LOCK: lock=d97cc9cc handle=cac6f768 mode=N >
> and time you already invested. > > Henry > > > ---------------------------------------------------------------- > Please see the official ORACLE-L FAQ: http://www.orafaq.com<http://www.orafaq.com>
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-- Mladen Gogala Oracle DBA ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com <http://www.orafaq.com> ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ <http://www.freelists.org/archives/oracle-l/> FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html <http://www.freelists.org/help/fom-serve/cache/1.html> ----------------------------------------------------------------- -- Binary/unsupported file stripped by Ecartis -- -- Type: application/ms-tnef ---------------------------------------------------------------- Please see the official ORACLE-L FAQ: http://www.orafaq.com ---------------------------------------------------------------- To unsubscribe send email to: oracle-l-request_at_freelists.org put 'unsubscribe' in the subject line. -- Archives are at http://www.freelists.org/archives/oracle-l/ FAQ is at http://www.freelists.org/help/fom-serve/cache/1.html -----------------------------------------------------------------Received on Wed Apr 28 2004 - 00:09:51 CDT
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