This section describes individual components of the PolyMix-4 workload
and is mostly auto-generated from PGL configuration files. The
configuration files should be consulted whenever a conflict in
documentation is suspected.
3.1
Phase schedule
The workload schedule consists of 10 phases. The schedule includes 9 phases with time-based goals and 1 other phase. The total test duration (based on the time-based goals) is about 10.33hour.
|
Phase
|
Factors (%)
|
Other
|
|
Populus
|
Recurrence
|
Special Msgs
|
|
beg
|
end
|
beg
|
end
|
beg
|
end
|
|
framp
|
0.04
|
50.00
|
9.09
|
9.09
|
10.00
|
10.00
|
|
|
fill
|
50.00
|
50.00
|
9.09
|
9.09
|
10.00
|
10.00
|
wait for WSS to freeze
|
|
fexit
|
50.00
|
0.04
|
9.09
|
100.00
|
10.00
|
100.00
|
|
|
inc1
|
0.04
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
top1
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
dec1
|
100.00
|
10.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
idle
|
10.00
|
10.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
inc2
|
10.00
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
top2
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
100.00
|
|
|
dec2
|
100.00
|
0.04
|
100.00
|
100.00
|
100.00
|
100.00
|
|
Phase "framp" lasts for 20.00min. During this phase, the robot population size increases from 0.04% to 50.00%. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 9.09% of robot recurrence ratios. The portion of special messages remains stable at 10.00%.
Phase "fill" does not have a time-based duration configured. During this phase, the robot population size remains stable at 50.00% of its peak level. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 9.09% of robot recurrence ratios. The portion of special messages remains stable at 10.00%. 1 samples of per-transaction statistics are collected. The phase will continue until working set size is frozen.
Phase "fexit" lasts for 20.00min. During this phase, the robot population size decreases from 50.00% to 0.04%. The offered per-robot load remains stable at 100.00% of its peak level. The offered recurrence level increases from 9.09% to 100.00% of robot recurrence ratios. The portion of special messages changes increases from 10.00% to 100.00%.
Phase "inc1" lasts for 20.00min. During this phase, the robot population size increases from 0.04% to 100.00%. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%.
Phase "top1" lasts for 4.00hour. During this phase, the robot population size remains stable at 100.00% of its peak level. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%. 1 samples of per-transaction statistics are collected.
Phase "dec1" lasts for 20.00min. During this phase, the robot population size decreases from 100.00% to 10.00%. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%.
Phase "idle" lasts for 20.00min. During this phase, the robot population size remains stable at 10.00% of its peak level. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%.
Phase "inc2" lasts for 20.00min. During this phase, the robot population size increases from 10.00% to 100.00%. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%.
Phase "top2" lasts for 4.00hour. During this phase, the robot population size remains stable at 100.00% of its peak level. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%. 1 samples of per-transaction statistics are collected.
Phase "dec2" lasts for 20.00min. During this phase, the robot population size decreases from 100.00% to 0.04%. The offered per-robot load remains stable at 100.00% of its peak level. The recurrence level remains stable at 100.00% of robot recurrence ratios. The portion of special messages remains stable at 100.00%.
3.2
Servers configuration
The workload defines 1 server type.
Server "PolyMix-4-srv" hosts the following 4 content types: "image" (65.00% of all hosted content), "HTML" (15.00%), "download" (0.50%), and "other" (19.50%). The following 3 content types can be accessed directly: "HTML", "download", and "other". Server "think time" distribution is set to norm(2.50sec, 1.00sec). This server uses persistent connections. The number of transactions per connection is distributed as zipf(16). Idle persistent connections are closed after a 15.00sec timeout. Only basic reply types are used.
3.3
Robots configuration
The workload defines 1 robot type.
Robot "PolyMix-4-rbt" is a "constant request rate" robot with request rate of 0.40 requests per second. About 50.00% of requests refer to URLs in a globally shared, public working set. This robot revisits 91.67% of previously requested URLs (offering a hit when a URL is cachable). About 100.00% of embedded objects will be loaded.
This robot is not allowed to open more than 4 connections at any given time, even if that limit causes decrease in request rate or memory exhaustion. Moreover, waiting transaction queue can grow without bounds. Robot's private cache is limited to 1000 entries. This robot uses persistent connections. The number of transactions per connection is distributed as zipf(64). Idle persistent connections are never closed by this robot. The following 3 request types are used: "IMS" (20.00% of all possible request types), "Reload" (5.00%), and "Basic" (75.00%).
"PolyMix-4-rbt" robots direct 10.00% of all requests to 1.00% of the working set, using popUnif() popularity distribution.
3.4
Content types
The workload uses 4 unique content types.
|
Type
|
Reply Size
|
Cachability
|
Extensions
|
|
image
|
exp(4.500KB)
|
80.00%
|
.gif, .jpeg, and .png
|
|
HTML
|
exp(8.500KB)
|
90.00%
|
.html and .htm
|
|
download
|
logn(300.000KB, 300.000KB)
|
95.00%
|
.exe, .zip, and .gz
|
|
other
|
logn(25.000KB, 10.000KB)
|
72.00%
|
|
The size distribution for "image" content type is exp(4.500KB). About 80.00% of "image" objects are cachable. This content type does not contain other types. The following 3 extensions may appear at the end of URLs: ".gif", ".jpeg", and ".png".
The size distribution for "HTML" content type is exp(8.500KB). About 90.00% of "HTML" objects are cachable. This content type is a container. Objects may contain (embed) the following 1 content type: "image" (100.00% of all embedded content). The number of embedded objects per container is distributed as zipf(13). The following 2 extensions may appear at the end of URLs: ".html" and ".htm".
The size distribution for "download" content type is logn(300.000KB, 300.000KB). About 95.00% of "download" objects are cachable. This content type does not contain other types. The following 3 extensions may appear at the end of URLs: ".exe", ".zip", and ".gz".
The size distribution for "other" content type is logn(25.000KB, 10.000KB). About 72.00% of "other" objects are cachable. This content type does not contain other types.
3.5 WAN latency and packet loss
The Polygraph client and server machines are configured to
use FreeBSD's DummyNet feature.
We configure Polygraph servers with 40 millisecond delays (per
packet, incoming or outgoing), and with a 0.05% probability of dropping a
packet (incoming or outgoing). Server think times are normally
distributed with a 2.5 second mean and a 1 second standard
deviation. Note that the server think time does not depend on the oid.
Instead, it is randomly chosen for every request.
We do not use packet delays or packet loss on Polygraph clients.
3.6 Other
Histograms and aggregate stats for PolyMix content types based on Squid
caching proxy tests are available elsewhere.
This section describes algorithms and rules used to allocate domain
names and IP addresses used in PolyMix-4. Most of the addresses are
computed automatically based on request rates and address space parameters
specified in the workload file.
5.1 Robot addresses
The number of PolyMix-4 robots is determined by peak request rate.
Each robot is capable of producing 0.4 req/sec load. The total number of
robots is adjusted so that every client-side host has the same number of
robots (other similar minor adjustments are also made). The number of
hosts is determined based on the maximum host load of 500 req/sec.
Two robots share the same IP address. All IP addresses use /22
subnet.
To allocate IP addresses for robot pairs, Polygraph iterates through the
client-side addr_space array and gives the next robot pair the
next IP address, until enough IP addresses are allocated for a host.
Polygraph then skips remaining IP addresses that belong to the same /22
subnet (if any), and starts allocation for the next host (if any).
The above scheme ensures that individual IPs do not "migrate" from one
host to another when request rate changes. Instead, only the number of IPs
"enabled" on each host changes.
Robot addresses are bound to loopback interfaces. The bench setup must
provide appropriate routes for robots to be able to communicate with the
world.
PolyMix-4 uses lo0::10.X.0-123.1-250/22 client-side address
space, where X is the bench ID that can vary from 100 to 199.
5.2 Server addresses
Server-side IP allocation algorithm is very similar to the client-side
algorithm described above. The only significant difference is that the
total number of server agents is computed as 500 + 0.1*R, where
R is the total number of robots.
Each server gets a unique IP address. PolyMix-4 uses
lo0::10.101.128-251.1-250:80/22 server-side address space.
In addition to server IP addresses, PolyMix-4 uses domain names. Each
server gets a unique domain name derived from the server IP address using
the IpsToNames() PGL function call. The mapping is 1:1. All
domain names have the same length. All domain names belong to the
"bench.tst" zone. Robots know the servers by their domain names rather
than IP addresses.
Needless to say, PolyMix-4 tests require a functioning DNS server.
5.3 Proxy address
If Polygraph robots should use a proxy address, that single address
must be 172.16.X.32 where X is the bench ID.