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The script used in this test is a single a single threaded script and
as such is limited by its capacity
to service requests on the provision that it has completed the previous
request in its entirity and will not service
further request until the previos request has been closed . So without
further ado , the figures .
The first illustration shows the results of the cgisock
script interacting with a single client producing
1000 requests in sequence pending reults from the server . This graph
gives a somewhat basic overview of
the consistent server response of a script that is ready and waiting
for the next hit . The colour scheme is
as follows .... The yellow dots represent the responses given
by the cgi server and the blue dots represent the
same content delivered by the Apache server as a static html page .
An important point must be made here
that the platform used is Linux and as such , once several calls have
been made on the same page , the Linux
Kernel will cache that page so that repeated disk accesses are
not required .
Figure 1. 1000 accesses with CGISOCK vs Static page serving.
The second illustration depicts a simulation of 10 clients accessing
the server simultaneously with each
client accessing the same page content 200 times to give an overall
2000 serves for the entire simulation.
Note that for this test ( as with all the test in this bracket ) 20
server processes were used .
Figure 2. 2000 accesses with 10 simultaneous clients
In this simulation it must be noted that although there are ten times
more clients to the single thread
process producing the web pages the responses from the the CGI server
manages to retain a near
linear reponse time to the client requests . The third illustration
simulates 100 clients trying to access
the same page simultaneously . Although there are 100 clients accessing
the same server , it still
manages to attain a near linear reponse time to the increased load
. The completetion time for all the
tests illustrated in this page was approximately 56 seconds , demonstrating
the maximum serving
capacity of this script which served all 2000 requests without failure
.
Figure 3. 2000 accesses with 100 simultaneous clients
Further Results: Faster than static file serving
After some more krufting of code , I present for your enjoyment further
results from the
torture chambers . Deep in the dungeons of the Castle and after some
krufting kludging together
of C source code , two more scipts were added to the cgisock test harness
series . The first was
a single thread program that does exactly the same thing as test_harness
, only faster , the
second is a multi - process monster using simmilat techniques to Apache
itself . Using this
its was possible to out serve apache static file serving under heavy
loads . The following
illustration depicts one of the runs where Apache kept its act together
for the duration
of the test . Please note that pushing Apache this hard on such limited
hardware can uncover
bugs that do not usually show up . Average hit rates of about 65 hits
per minute were
typical .
Figure 4. 1000 accesses with 100 simultaneous clients
Please note that not long after this test , Apache stopped serving pages
and started acting
erratically . The reason was that I had hit the server with sufficient
hits to swamp syslogd
and as such apache welded shut while the syslogd was restarting ( serval
times withing the
space of about several seconds . Me Apache log had grown to over 4Mbytes
in length .)
The second illustration is with a reduced server count ( 20 server
children were begining to get in
each others way so I dropped the count . The CGI server children count
was 6 ).
Figure 5. 2000 accesses with
100 simultaneous clients
The above benchmarks were carried out using Apache 1.3.4 with mod_cgisock
0.1.0 on a 486 dx 133 .
The 486 was equiped with 40Mb of RAM with a 4.2 Gbyte Seagate IDE Hard
drive over a PCI bus
connection . The client machine was a equipped with a Cyrix 300 Mhz
Process running blackdowns
JDK V1.17 Linux port , Window Maker Version 0.4 a Seagate 4.2 Gbyte
Hard drive 32Mbytes of
RAM and a 75Mhz PCI bus . The network interfaces were accomplished
with two ( extremely budget )
ne 200 compatible 10 base 2 10Mbit/s ethernet cards on ISA interfaces
. The operating system used on
both machines was Linux 2.0.36 which ( as usual ) performed flawlessly
. The output from
Velocigens(TM) VeloMeter(TM)was resized using the GIMP in conjunction
with xpaint for
gif converstion . All trademarks are copyright of their respective
owners and Linux is a
copyright of Linus Torvalds .
This document has been prepared in the interests of the general public .
