Simulating a Distributed
Collaborative Environment
Jon A. Preston
CSc8350 – Dr. Xiaolin Hu
Purpose
• Examine the interactions among clients
and servers in a distributed artifact
management system
• Examine how adding a middleware
(capable of fine-grain locking) can be
added and how such a change effects
collision rate (fail rate) of checkouts
• Examine various client behaviors
– Random, Clustered, Hybrid
Initial Version
Adding the Proxy Middleware
• Middleware added to
ServerMachine
• Maintains DB of
artifacts checked out
• Each artifact contains
subsections
• Check out/in passed
to server only as
needed
• Server & Repository
unchanged
System with Middleware
Results
Client Distribution
Repository Distribution (# Artifacts)
Fail Rate
Without Finegrain Locking
With Finegrain Locking
1
32.75
7.27
2
1
23.33
11.67
1
2
1
26.92
6.38
3
1
2
1
19.64
7.02
1
1
10
20
10
2.00
0.75
10
10
10
30
50
80
30
30
40
40
100
100
16.39
5.81
5000
10
10
10
30
50
80
30
30
40
40
100
100
7.91
2.62
8
2500
10
10
10
15
25
40
15
15
20
20
50
50
9.08
2.99
9
5000
1
1
1
1
2
1
26.55
7.24
Test
Iterations
Random
Clustered
Hybrid
S1
S2
S3
1
500
1
1
1
1
2
2
500
3
0
0
1
3
500
0
3
0
4
500
0
0
5
500*
1
6
500
7
S4
S5
S6
* Test 5 for the fine-grain version was run to 5000 iterations to obtain lock failures
S7
S8
S9
Future Work
• Implement a parsing algorithm to generate
authentic subsections in artifacts (open
source repository)
• Better analyze and model clients’ edit
behaviors