1. REMOTE++: A Tool for Automatic Remote
Distribution of Programs on Windows Computers
Ashley Hopkins
Department of Computer Science and Engineering
University of South Florida
Tampa, Florida
AMH001 (thesis.ppt - 04/16/03)

2. Acknowledgements
I wish to thank Dr. Kenneth Christensen for his encouragement,
his enthusiasm, and his support in writing this thesis.
I also wish to thank my committee member Zornitza Genova
Prodanoff for taking the time to read this thesis and provide
valuable feedback.
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3. Topics Introduction – remote distribution
Description of Remote distribution methods
Design of REMOTE++
Evaluation of REMOTE++
Summary and future work
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4. Introduction Two key issues addressed by remote distribution
Simulation programs require significant time to execute
Many require multiple runs to complete an experiment
Many computer resources are under utilized
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5. Introduction continued
Parallelization of programs reduces overall execution time
Two types of parallelization
Space based parallelization
Addresses programs that can be broken down easily
Time based parallelization
Addresses programs that require multiple executions
Many simulations fit this category
REMOTE++ implements time parallelization
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6. Introduction continued
Remote Distribution Network
Remote
Remote
Remote
Network
Master
Remote
Remote
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7. Introduction continued
Remote distribution of programs
Enables execution of independent programs in parallel
Harnesses the idle CPU cycles of remote machines
Reduces the overall execution time of experiments
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8. Introduction continued
Requirements of Distribution Tools
Distribution must be automatic (no manual interaction)
2) Tool must be simple for easy maintenance and modification
3) Output files must be available on the master PC
4) A single process must be distributed to each remote machine
5) Once a job completes, the next job must be sent
Each job must be executed only once
The failure of a job to complete must be detected
The failure of a remote host must be detected
Error messages must be displayed at the master PC
A log file should be kept
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9. Remote Distribution Methods
Methods for Remote Distribution
Remote shell (rsh) and remote execute (rexec) commands
Cluster systems
Beowulf
Grid Computing
Unix based remote distribution tools
Condor
Original REMOTE tool developed by Dr. Christensen
REMOTE++ built upon this tool
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10. Remote Distribution Methods continued
Drawbacks of current tools
Primarily designed for Unix platforms
Many are large or complex
Many require extensive installation and maintenance
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11. Remote Distribution Methods continued
Key challenge is…
Develop a Windows based Remote Distribution tool
that is easy to use, maintain, and modify.
Must be able to reduce overall execution time
Overhead in distribution of processes must be overcome
Must be able to execute many different programs
No modification to the programs
Various input and output methods allowed
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12. Description of REMOTE++
REMOTE++ is built upon REMOTE
Sockets interface replaced by rcp/rsh commands
Programs read/write to standard input/output
An invalid job is detected
An invalid host is detected
REMOTE++ also has drawbacks
Each remote host required to have an rsh/rcp daemon
Status feature of REMOTE not available
Security concerns with remote shell commands
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13. Description of REMOTE++ continued
Set-up of REMOTE++
1) Each client must have a remote shell/remote copy daemon.
2) REMOTE++ must be loaded on the master machine.
3) A joblist.txt file must contain a list of jobs to be
executed.
4) A hostlist.txt file must contain a list of the hostnames
of all remote machines.
5) A status.txt file must be created as a log file containing
the success or failure of each job and each remote host.
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14. Description of REMOTE++ continued
Sample joblist.txt file
file mm1.exe input1.txt output1.txt
std hello.exe input2.txt output2.txt
file mm1.exe input3.txt output3.txt
Sample Hostlist.txt file
giga2.csee.usf.edu
giga3.csee.usf.edu
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15. Description of REMOTE++ continued
Sample status.txt file
Mode is classic.
Executable file mm1.exe found
Input file input1.txt found
Output file output1.txt found
Mode is new.
Executable file hello.exe found
Input file input2.txt found
Output file output2.txt found
Input file input3.txt was not found
Output file output3.txt found
giga2.csee.usf.edu is a valid host
giga3.csee.usf.edu is a valid host
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16. Description of REMOTE++ continued
Operation of REMOTE++
1) The existence of each job in joblist.txt is validated.
2) Threads are used to assign a job to each host in the host list.
3) The executable is remote copied (rcp) to the remote host.
rcp failure makes host unavailable and job is reassigned
4) The job is executed using a remote shell (rsh) command.
5) When the job finishes the host is assigned another job
until all jobs in joblist.txt are complete.
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17. Description of REMOTE++ continued
Sample Execution of REMTOE++
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18. Description of REMOTE++ continued
Two input/output methods are supported by REMOTE++
1) File or “Classic” method
Used with programs that read from and write to files
Implemented in original REMOTE tool
Requires transfer of input and output files
2) Std or “New” method
Used with programs that use standard input/output
New in REMOTE++ tool
Input and Output redirected from files
No transfer of files required
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19. Description of REMOTE++ continued
The remote shell/remote copy daemon:
1) Vendor version (tested with Denicomp’s rshd)
Dependable
Cost prohibitive
Not open source
2) Free version (by Silviu Marghescu)
Free
Open source
Does not support standard input/output method
Not as reliable
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20. Evaluation of REMOTE++
Queuing systems can be modeled using simulation
Queue simulations must be executed numerous times with varying
input to gather statistical information
A queue simulation was utilized to evaluate the REMOTE++ tool
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21. Evaluation of REMOTE++ continued
A queue is a sequence of customers waiting to receive service
The following features determine the behavior of a queue:
The distribution of time between arriving customers
The distribution of time to service a customer
The number of servers available to service the customers
The capacity of the queue
The population size of customers
The queuing discipline determines the order of service
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22. Evaluation of REMOTE++ continued
An M/M/1 queue has the following features:
Markovian (exponentially distributed) inter-arrival of
customers
Markovian (exponentially distributed) service times
A single server
An unlimited queue capacity
An infinite customer population
An M/M/1 queue has FIFO queuing discipline
Server
Arrivals
Queue
Departures
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23. Evaluation of REMOTE++ continued
Evaluated REMOTE++ with an M/M/1 queue simulation
Performance of an M/M/1 queue measured by its utilization
Utilization (ρ) is the fraction of the time the system is busy
Utilization is a ratio of arrival rate and the service rate
The length (L) of the queue is dependent on the utilization
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24. Evaluation of REMOTE++ continued
Goal of Evaluation…
Determine the relationship between the utilization and the
simulation run time for mean queue length within a percent
of the theoretical length
At the same time…
Evaluate the reduction in execution time when executing
simulation with REMOTE++ on five machines
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25. Evaluation of REMOTE++ continued
M/M/1 queue simulation time was evaluated for...
Utilization from 1% to 99.5%
Length within 10% of the theoretical length
Statistical mean of 10 executions at each interval
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26. Evaluation of REMOTE++ continued
As the target utilization approaches 100% the simulation time
of the M/M/1 queue increasingly grows longer.
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27. Evaluation of REMOTE++ continued
Simulation time grows slightly faster than order six
polynomial growth
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28. Evaluation of REMOTE++ continued
The M/M/1 queue execution...
Projected a five time speed up on five machines
Achieved about two and a half time speed-up on five machines
seven seconds of overhead per job
at low utilization jobs executed in several seconds
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29. Summary and future work
Remote Distribution can be used to reduce execution time.
Existing systems are Unix-based and complex
Need a simple Windows based tool
REMOTE++ improves upon REMOTE
Complex sockets interface replaced by simple rsh/rcp script
Enables wider variety of programs to be executed
Able to recover from invalid jobs and hosts
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30. Summary and future work
Improve free remote shell daemon
Support std or “new” input/output method
Reduce overhead in distribution to increase reduction in execution
time.
Support more and mixed input/output methods
Implement security in REMOTE++
Currently relies on rsh daemon for security
Implement status feature similar to original REMOTE tool
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31. Thank You Questions? Ashley Hopkins
Department of Computer Science and Engineering
University of South Florida
Tampa, Florida
REMOTE++ soon available at:
Thank You
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