AMH001 (thesis - 04/16/03)

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 33620 amhopki2@csee.usf.edu 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. AMH002

3. Topics • Introduction – remote distribution • Description of Remote distribution methods • Design of REMOTE++ • Evaluation of REMOTE++ • Summary and future work AMH003

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 AMH004

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 AMH005

6. Introduction continued • Remote Distribution Network Remote Remote Remote Network Master Remote Remote AMH006

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 AMH007

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 AMH008

9. Remote Distribution Methods • Methods for Remote Distribution • Remote shell (rsh) and remote execute (rexec) commands • Cluster systems • Beowulf • Grid Computing • SETI@home • Unix based remote distribution tools • Condor • Original REMOTE tool developed by Dr. Christensen • REMOTE++ built upon this tool AMH009

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 AMH010

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 AMH011

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 AMH012

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. AMH013

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 AMH014

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 • Mode is classic. • 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 AMH015

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. AMH016

17. Description of REMOTE++ continued • Sample Execution of REMTOE++ AMH017

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 AMH018

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 AMH019

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 AMH020

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 AMH021

22. Queue Server Arrivals Departures 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 AMH022

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 AMH023

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 AMH024

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 AMH025

26. Evaluation of REMOTE++ continued • As the target utilization approaches 100% the simulation time • of the M/M/1 queue increasingly grows longer. AMH026

27. Evaluation of REMOTE++ continued • Simulation time grows slightly faster than order six • polynomial growth AMH027

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 AMH028

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 AMH029

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 AMH030

31. Questions? Ashley Hopkins Department of Computer Science and Engineering University of South Florida Tampa, Florida 33620 amhopki2@csee.usf.edu • REMOTE++ soon available at: • http://www.csee.usf.edu/~amhopki2/research • http://www.csee.usf.edu/~christen/tools/toolpage.html Thank You AMH031