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Home -> Community -> Mailing Lists -> Oracle-L -> virtual circuit wait/shared server
Solaris 9 E4500 6-cpu 6 gigs mem
Oracle 9.2.0.4
We have a vendor-supplied app that was upgraded recently. The database is using shared server. We peak at about 1000 to 1050 sessions mid-morning.
Users complain of slowness compared to the old system. Nothing horrible, but they just perceive it’s not as quick as it used to be. Vendor consistently says the database is screwed up.
Before the upgrade it was rare to EVER see a session waiting on the virtual circuit latch. Now it’s just as rare to see no sessions waiting. 2 differences between old and new version of software: more sessions connected, and introduction of Citrix.
Virtual circuit status always tops our wait events. These are from 3 different statspack reports on 3 different days during peak morning hours. These numbers are typical:
Avg
Total Wait wait Waits
Event Waits Timeouts
Time (s) (ms) /txn
---------------------------- ------------ ----------
---------- ------ --------
virtual circuit status 460,380 2,831
100,414 218 19.6
virtual circuit status 526,272 2,801
99,410 189 30.4
virtual circuit status 372,273 1,677
65,342 176 15.3
-------------------------------------------------------------
When I push any statspack report through yapp, the
advice always comes back to tune mts:
Maximum gain: 94% what: Tune Multi-Threaded Server.
Trouble is that I don’t know what to tune. I have 2 dispatchers. They barely break a sweat, normally about 0.4 % busy, about a 0.04 avg wait.
I have 20 servers defined. The first couple get busy
(maybe up to 20% or so), but most of the servers do
not get used at all.
Any ideas? I’d be delighted for any help.
Barb
Here’s output from the mts script supplied on Tim Gorman’s web site:
MTS Dispatcher Statistics:
Name Owned Status Type Queued %Busy Avg
Wait
---- ----- -------- ---------- ------ --------
--------
D000 473 WAIT DISPATCHER 0 0.586
0.055
D001 464 WAIT DISPATCHER 0 0.582
0.054
----- --------
--------
avg 0.584
0.055
sum 937
MTS Shared Server Statistics:
Name Total Rqsts Rqst/Hour Rqst/Min %Busy
---- ------------ ------------ ------------ --------
S000 694,988 65,964.217 1,099.404 22.916
S001 350,251 33,243.787 554.063 10.856
S002 160,438 15,227.841 253.797 4.700
S003 58,155 5,519.734 91.996 1.854
S004 19,332 1,834.881 30.581 0.777
S005 5,678 538.923 8.982 0.340
S006 1,869 177.395 2.957 0.204
S007 704 66.820 1.114 0.184
S008 257 24.393 0.407 0.150
S009 245 23.254 0.388 0.107
S010 178 16.895 0.282 0.087
S011 151 14.332 0.239 0.085
S012 117 11.105 0.185 0.088
S013 93 8.827 0.147 0.090
S014 42 3.986 0.066 0.064
S015 41 3.891 0.065 0.060
S016 44 4.176 0.070 0.034
S017 31 2.942 0.049 0.047
S018 60 5.695 0.095 0.035
S019 38 3.607 0.060 0.023
--------
avg 2.135
MTS "Active Circuit" Statistics:
Session
Circuit ID,Serial# Disp Serv Queue Waiter
-------- ---------- ---- ---- -------- --------
2FA16850 38,454 D001 S001 SERVER 00
2FA16E20 17,41 D000 S002 SERVER 00
2FA68E4C 309,81 D000 S000 SERVER 00
Cumulative MTS Statistics:
Maximum Servers Servers
Servers
Connections MAXIMUM_SESSIONS Started Terminated
HighWater
----------- ---------------- ---------- ----------
----------
940 940 2 2
21
MTS configuration parameters:
Name Value
--------------------
-------------------------------------------------------
mts_dispatchers
mts_servers 20
mts_max_servers 100
mts_max_dispatchers 200
mts_circuits 1400
mts_sessions 1395
mts_service sidname
mts_listener_address
mts_multiple_listene FALSE
-- 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 Thu Apr 15 2004 - 12:53:58 CDT
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