SEKE 2012 Proceedings - Knowledge Systems Institute

integrate the test results.
• Autotest, which is a framework for automated testing.
• Eucalyptus, which manages Xen nodes u sing cloud
controller, node controller and so on.
• Xen nodes, which makes virtual machine available by
virtualization in cloud infrastructure.
A. Test_Manager
T est_Manager is a module developed using Web
framework Django. It is the control center of AT-Cloud, which
manages the communication among the Web, Eucalyptus and
Autotest. The functions of Test_Manager are as follows:
1) Receives the test task, configuration file and test scene
flow graph from tester. The test task includes test source code,
test scripts based on test scene flow graph. The configuration
file describes the hardware and software environment
requirement of a test task.
2) Analyzes test scene flow graph and finds parallel paths
according to the prime path coverage criterion.
3) Transfers emi-id, unique ID of the registered machine
software image on the cloud, to the cloud controller.
4) Registers virtual machines to Autotest Server as clients
and schedules parallel test paths to run on the registered VMs.
5) Collects test results produced by each test path from
Autotest and integrates them together.
B. Autotest
A utotest is an open test framework for implementing
automated test. The test procedures are shown as follows:
1) Autotest Server receives test source code, test scripts
from Test_Manager.
2) Autotest Server receives VM IP address from cloud and
adds the VM IP to Autotest Server’s host list as an Autotest
client.
3) Scheduled by Test_Manager, Autotest Server creates test
job and run test job on Autotest client.
4) Autotest Server saves test results for every test.
C. Eucalyptus
A T-Cloud deploys virtual machine resource using
Eucalyptus, which comprised five components: Cloud
Controller, Walrus, Cluster Controller, Storage Controller, and
Node Controller. The procedures of providing virtual machine
resources VMs are as follows:
1) The cloud controller receives emi-id from Test_Manager.
2) According to the emi-id, Eucalyptus chooses or launches
an instance of VMs.
3) After creating an VM instance, Eucalyptus assigns the
instance an IP address, and this IP address will be transmitted
to Autotest Server by Test_Manager.
D. Xen
AT-Cloud uses Xen as virtualization software. Xen is a
virtual-machine monitor providing services that allow multiple
computer operating systems to execute on the same computer
hardware concurrently [7].
III. FINDING PARALLEL TEST PAHTS
Path test is a k ind of structure test based on program
source code in white-box test, which derives test path from
program graph [8]. In this paper, path test is introduced for
software function testing, modeling the test scene flow based
on prime path coverage criterion.
A. Test Scene Flow Graph and Test Path
By decomposing software functions based on the scenes of
a unit test, we can design the test cases according to the test
equivalence class, and use a test scene flow graph to describe
the function point and their relationships, which may have a
number of test paths.
B. Prime Path Coverage Criterion
Prime path coverage criterion has the practical advantage
of finding the parallel paths and improving the test coverage.
In prime path coverage, tests should tour each prime path in a
test scene flow graph. Prime path coverage requires touring all
subpaths of length 0 (all nodes), of length 1 (all edges), length
2, 3, etc. Thus it subsumes node coverage, edge coverage and
edge-pair coverage, which have a high path coverage rate [9].
The following are definitions about prime path coverage
criterion:
1) Simple path: n i and n j are nodes in test scene flow graph
G. A path form n i to n j is a simple path if no node a ppears
more than once in the path, with the exception that the first
and last nodes may be identical.
2) Prime path: A path from n i to n j is a prime path if it is a
simple path and it does not appear as a proper subpath of any
other simple path.
3) Prime path coverage (PPC) criterion: Test requirement
contains each prime path in graph G.
C. Finding Parallel Test Paths
According to PPC criterion, after finding all prime paths in
a graph, the parallel test paths can be obtained as follows.
1. Set up a test scene flow graph G
2. For path-length from 0 to the longest simple path in G,
find all possible prime path
If the simple path's final node in G has no outgoing
edges or the simple path's node is a lready in the
path and not the first node
A dd the simple path to path-list
Else
E xtending the simple path with every node that
can be reached from the final node
3. If one path in the path-list is a proper sub path of another
path in the path-list
Re move the path from the path-list, finally all the
pr ime paths will be found
4. For each prime path in the path-list
S tarting with the longest prime paths and extends
them to the beginning and end nodes in the graph
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