[Zope-DB] Zope-DCOracle2 vs Tomcat-JDBC performance

[Umberto Nicoletti]

Hi all,
we're proud users of Zope, but recently we ran into some performance
issues.

We have some Zope applications that are database (Oracle) intensive and
recently experienced some *huge* slowdowns when under heavy usage. We
had no problems before because the usage was modest (under 5 concurrent
users).
Since this is SHOW STOPPER for us we decided to spend some time and 
investigate further. We took a server and installed Zope 2.6.1, python 
2.1.3 and DCOracle2 1.3b on Suse
Linux 8.0. On the same server we installed jakarta tomcat 4.1.24 with 
Sun JDK 1.4.1_02 and Oracle JDBC.

On another server (identical HW and SW) we have an Oracle 8.1.7 instance 
and so we ran some simple queries against it from Zope and Tomcat.

Result is that with small pages in both size and number of records 
(under 5) displayed Zope is head to head with Tomcat.

With larger pages (about 50 records displayed with no whatsoever html
tables or other embellishment) Tomcat is MUCH faster (see below).

We believe the problem is somehow related to threading issues in
Zope/Python.

Can anyone help us figure out what's wrong with our Zope setup?
Best regards,
Umberto

Env Details:

HW (for both Zope/Tomcat and Oracle): PIII 1GHZ, 256 MB RAM, 2 Ultra160 
SCSI drives (HP NetServer E800), 100Mb Switched Ethernet

Zope:
	2.6.1
	Startup parameters:
/usr/bin/python /opt/zope261/z2.py -X -f 7022 -t 7 -i 250 -w 7080 -u 
zope -z /opt/zope261 -Z /var/run/zope.pid -L en_US -l /var/log/zope.log

	We tried this optimization (second zope run):
#cat /opt/zope261/custom_zodb.py
import ZODB.FileStorage
import ZODB.DB
import os.path

filename = os.path.join(INSTANCE_HOME, 'var', 'Data.fs')
Storage = ZODB.FileStorage.FileStorage(filename)
DB = ZODB.DB(Storage, pool_size=7, cache_size=8000)
#EOF

Tomcat:
	4.1.24 binary from jakarta.apache.org
	Sun JDK 1.4.1_02
	*NO OPTIMIZATION WHATSOEVER*

	The page querying Oracle opens a connection for every user and that is 
saved into the session. So there are as many connections opened at the 
end of a test run as are the users.

Test client:
	JMeter built from cvs 1 week ago

Test setup:
	two jmeter slave and one server: 25 threads, ramp up time 10, loop
count 5 (total of 250 requests)

test items:
	1 static page, jakarta_html (about 30K = jakarta.apache.org home page)
	1 dynamic page, lista50 from Oracle DB (about 22K = first 50 of 1700 
records from select)

TEST results:

all times in ms
rt=response time: from first byte sent of the request to last byte
received

Round 1 (static page and dynamic with 50 records showed from db):

page		req.	avg	min	max	errors	rate
		number	rt	rt	rt	
	----------------------ZOPE----------------------
jakarta_html	250	52710	50	112752	0,00%	22,9/min
/test/lista50	250	73238	10405	140512	0,00%	21,5/min
	------------ZOPE with custom_zodb.py------------
jakarta_html	250	52740	20	109748	0,00%	22,8/min
/test/lista50	250	73026	11246	133833	0,00%	21,6/min
	---------------------TOMCAT---------------------
/jakarta.html	250	560	0	2604	0,00%	10,4/sec
/index.jsp	250	455	40	2944	0,00%	10,4/sec

Comparison results (CSV format for your graphing pleasure):

Response times per URL (ms),(max1),(max2),(max1-max2),(%)
index.jsp,133833,2944,130889,97.80
jakarta.html,109748,2604,107144,97.63

max1=zope
max2=tomcat

Response times per URL 
(ms),(samples),(max1),(avg1),(min1),(max2),(avg2),(min2)
index.jsp,250,133833,73026,11246,2944,455,40
jakarta.html,250,109748,52740,20,2604,560,0

max1,min1,avg1=zope
max2,min2,avg2=tomcat

As you see the difference is enourmous.