Fragmentation Investigation And Evaluation In Distributed DBMS Using JDBC and OGSA-DAI by ijcsiseditor

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									                                                               (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                  Vol. 8, No. 9, 2010

    FRAGMENTATION INVESTIGATION AND
  EVALUATION IN DISTRIBUTED DBMS USING
           JDBC AND OGSA-DAI

                            Ahmed Almadi, Ahmed Manasrah, Omer Abouabdalla, Homam El-Taj
                                        National Advanced IPv6 Center of Excellence (NAv6)
                                                 UNIVERSITI SAINS MALAYSIA
                                                         Penang, Malaysia
                                             {almadi, ahmad, omar, homam}@nav6.org

Abstract— This research investigates and evaluate the impact of                Moreover, some noticeable overheads are come into view
the fragmentation on different database retrieval modes based on           clearly from several new technologies in the distributed
derived horizontal fragmentation by generating and distributing            systems such as OGSA-DAI middleware. A reason is that the
the query to the servers (distributed search) or send the query to         high-level technologies and processing gives a noticeable
the direct server (direct search). Moreover, it provides
                                                                           overhead. In particular, the perceptible overheads are
recommendation on suitable query execution strategies based on
a proposed fitness fragmentation formula. Furthermore, examine             appearing clearly on retrieving databases and accessing the
the suitable technology such as OGSA-DAI and JDBC in grid                  distributed systems. From this point of view, main research
database to examine the time overhead in distributed systems and           question is "How to reduce the overhead in the grid systems
grid environments in different cases like size or number of                and distributed systems on distributed database retrieval
servers. The results show that the fragmentation's time                    service?"
performance impact is clearly effective and positively applied             Sub-questions arise from the research are as the following:
while increasing the database size or the number of servers. On             • What is the best database size to apply the fragmentation
the other hand, the OGSA-DAI kept on showing slower execution
                                                                                 if we consider the performance in order to generate sub-
time on all conducted scenarios, and the differences between the
execution time exceeds up to 70% while increasing the size of
                                                                                 queries to the servers or just to the local server?
data or number of servers. In addition, this thesis has tested the          • What is the tradeoff between transparency and the
impact of fragmentation search against the distributed search                    performance in case of using JDBC and OGSA-DAI?
where the first one submit the query to direct server(s) (direct
search), and the second one distribute the query to the servers                This paper focuses on the impact of the fragmentation on
(distributed search). The result shows that the speed effectiveness        different cases of database systems, and on the JDBC
of direct search technique in JDBC case is around 70% faster               performance under several layers of executions against the
than the distributed search and around 50% faster in OGSA-DAI              OGSA-DAI. The evaluation part will be based a quantitative
case.
                                                                           evaluation and the execution time overhead is the main
    Keywords-component; JDBC; OGSA-DAI; Fragmentation;                     attribute of the evaluation.
Distributed DBMS
                                                                                             II.   LITERATURE REVIEW
                                                                                                   1B




                       I.    INTRODUCTION                                    1) Distributed Query Performance
                                                                                 16B




    In distributed systems, data are fragmented, located and                   In processing such an index partitioning scheme two
being retrieved in a transparent manner among the distributed              approaches are presented in response to a range query. A
sites[3]. Therefore, accessing some distributed data from                  comparison between such approaches and other similar
different locations are applied using a “View” of the data.                schemes is done in order to compare their performances.
However, technically, in the distributed systems, the catalogue            Accordingly, this performance is assessed from the
database is an essential demand where it makes an affix for the            perspective of the response time, system throughput network
physical location into the catalogue [11].                                 utilization and disk utilization. Taking in account varying the
    Moreover, web-services are playing a big role on retrieving            number of nodes and query mix [12].
the fragmented database and applying certain services.
Fragmentation is considered to be one of the most important                    Sidell in (1997) presented the distributed query processing
phases that is been conducted to achieve the distributed                   problem in Mariposa. A comparison of its performance with a
database design. Yet, the impact of the fragmentation                      traditional cost-based distributed query optimizer is obtained
performance on the case of increasing or decreasing the                    [9].
overhead is unclear.



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                                                                                                        ISSN 1947-5500
                                                             (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                Vol. 8, No. 9, 2010
    The ability to adapt a dynamic workload is displayed                 services model; trying to serve the needs of the various target
through a Mariposa system. In addition, the adaptive                     communities; and using the Globus Toolkit OGSI core
distributed query processing in Mariposa and its interaction             distribution [7].
with multi-user workloads, network latencies and query size                  In 2008, Hoarau & Tixeuil, presented an experimental
benefits are investigated. Performance results observed to               study of studying the OGSA-DAI [5]. Results were quite
show that the Mariposa system outperforms a static optimizer             stable and performed quite well in scalability tests, and were
as it distributes works regularly among the available sites.             executed on Grid5000. It is also discussed that the OGSA-DAI
Besides, it is to be noticed that the overhead which is                  WSI uses a SOAP container (Apache Axis1.2.1) which suffers
introduced by Mariposa's budding protocol gives insignificant            from severe memory leaks. It is shown that the default
results if it is used with large, expensive queries. In addition,        configuration of OGSA-DAI is not affected by that problem;
though for small queries it is outweighed by the benefits of             however, a small change in the configuration of a Web-service
load balancing. Truthfully , the comparisons based on the                could lead to very unreliable execution of OGSA-DAI [5].
TPC-D benchmark show that the authors' point of view in                      An OGSA-DQP is an open source service-based
which their approach behave as a static optimizer is influenced          distributed query processor. The evaluation of queries is
by network latency and query size [9].                                   supported by this processor. The OGSA-DQP effects over
    In 2003, a paper in title of “Distributed Query Processing           several layers of service-oriented infrastructure. Experiences
on the Grid” [10] argues on the significant of the distributed           in investigating the impact of infrastructure layers were
query processing in the Grid and on the facilities in the grid           discussed in a study in [1]. In addition, this study presents an
that support the distributed query processing producers. The             understanding of the performance issues, identify bottlenecks,
paper describes a Polar prototype implementation of                      and improve response times of queries. It also describes the
distributed query processing running over Globus. They used a            experiments carried out and presents the results gained [1].
bioinformatics case study to illustrate the benefits of the                  However, as illustrated in Figure 1 the processes in the
approach [10].                                                           OGSA-DAI which are in high-level schematically
    Oliveira et al., have presents in 2007 a paper that shows the        representations are passing through several layers of interfaces
development on the grid computing and a comparison was                   between each layer. Therefore, it gives the fact of the time
conducted on two algorithms for planning the distribution and            overhead performance through using the OGSA-DAI high-
parallelization of database equerry on grid computing [8].               level schematically representation to communicate and
Showing the partial order planning algorithm with resource               retrieve the database [6].
and monitoring constraints is the best choice for distribution
and parallel DBMS queries was their main contribution.

  2) Investigating the OGSA-DAI
    In grid computing, many investigations and studies on
OGSA technology where aim to decipher the importance of
OGSA-DAI and the benefits of its services.
    An overview of the design and implementation of the core
components of the OGSA-DAI project was presented in High-
                                                                                  Figure 1. OGSA-DAI architecture and flow processes
level manner. The paper describes the design decisions made
the project’s interaction with the Data Access and Integration
Working Group of the Global Grid Forum and provides an                                 III.   FRAGMENTATION FRAMEWORK
                                                                                              2B




overview of implementation characteristics. Implementation
                                                                             The derived fragmentation is a fragmentation where
details could be seen from the project web site [2].
                                                                         databases are fragmented according to a specific attribute.
    In describing experiences of the OGSA-DAI team, a team
                                                                         Since that, a catalogue table is a compulsion in the main server
has an experience in designing and building a database access
                                                                         to keep on mind knowledge for all fragmented databases.
layer using the OGSI and the emerging DAIS GGF
                                                                             Catalogue database is a database that contains the
recommendations [7].
                                                                         information of the distributed database. It contains the site, the
    They designed this middleware to enable other UK e-
                                                                         name of the database and the attributes in where the database
Science projects which need database access. It also provides
                                                                         was fragmented.
basic primitives for higher-level services such as Distributed
                                                                             We will apply a basic student database which consists of
Query Processing. In addition, OGSA-DAI intends to produce
                                                                         student’s information such as name, id and year of each
one of the required reference implementations of the DAIS
                                                                         student. Table I. shows the catalogue table which will be
specification once this becomes a proposed recommendation
                                                                         conducted in the research implantation.
and, until then, scope out their ideas, provide feedback as well
as directly contributing to the GGF working group [7].
    In this paper, issues that have arisen in tracking the DAIS
and OGSI specifications are presented. These issues appeared
during a development of a software distribution using the Grid




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                                                                                                      ISSN 1947-5500
                                                                   (IJCSIS) International Journal of Computer Science and Information Security,
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                   TABLE I.        CATALOGUE DATABASE

 Table
             FAbase           Dbname         Serverid     FAconstraints
 Name
Student           Year          DB1             S1             1
student           year          DB2             S2             2

Table I. above consists of 5 main attributes that displays the
main information about the fragmented relational or tables in
the distributed system:
 1. Table Name: contains the name of the fragmented tables.
 2. FAbase: contains the attribute where the tables where
     fragmented according on.
 3. Dbname: contains the name of the DB in the distributed
     servers where it handles the fragmented table.
 4. Serverid: contains the server ID to refer to the server’s
     IP for the distributed DB.
 5. FAconstraints: contains the value of the fragmentation
     base attribute for each table.


      IV.    MAIN FRAMEWORK FOR ENGINE SEARCHING
             3B




    In distributed systems, database retrieval process is
achieved on two main ways. The first way is to directly access
the server that contains the required data. The second
technique is to distribute the searching query into the
distributed servers. In this research, we will be calling these                  Figure 3. Flowchart for database retreiving based on catalogue database
two techniques direct search and distributed search
respectively.                                                                  A. SQL Processing Search
                                                                                   7B




    The system will take the decision of choosing the
searching method after analyzing and understanding the SQL                     In SQL processing step, several procedures will be done inside
statement. The decision will be based on the existing of the                   the engine to process the SQL, which are:
fragmentation attribute via the query, in such case, system will                   1. Getting the SQL statement from the web-server: in
choose the direct search and. The existing of the fragmentation                       the interface, the user will write the SQL statement for
attribute in the query means that the system can get directly                         retrieving certain data as a string.
the data from the distributed server(s) by getting the site of                     2. Select checking: (validation) does it start with
that server from the catalogue database, by referring to the                          “SELECT”, by using searching method for this word
FAbase in that table. In this case, the performance will be                           (select), if yes, continue to next step, else, give an error
higher since it reduces lots of time if it was using the                              message and back to the main page .
distributed search.                                                                3. Table Name Searching: After getting the SQL, a table
    From Figure 2. we can see the main architecture of the                            searching method will be called. Its main job is to
research framework. The processes can be categorized into                             search for the table's name inside the SQL statement
five main layers: User interface, SQL Processing System                               (string).
Management Connections (JDBC) and Servers pool.                                    4. Checking Name: checks if the name was mentioned
                                                                                      (the SQL statement is correct so far), if yes, save the
                                                                                      table name and continue to next step, else, give an error
                                                                                      message and back to the main page.
                                                                                   5. Retrieving Fragmentation Attribute (FA): Get the FA
                                                                                      style for that table from the catalogue database which is
                                                                                      saved in the main server.
                                                                                   6. FA Searching: Another searching method will be called
                                                                                      to search for the FA style in the SQL statement.
                                                                                   7. Found: If the FA was found in the SQL statement, the
                                                                                      system will choose the direct search; else it will choose
                                                                                      the distributed search.

                  Figure 2. Main framework and architecture




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                                                                                                               ISSN 1947-5500
                                                           (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                              Vol. 8, No. 9, 2010
B. Direct Search                                                       difference between using distributed processing using JDBC
In direct search step, after receiving the FA, several                 or OGSA-DAI as a quantitative evaluation based.
procedures will be done inside the engine to process and               Moreover, examining the significant of the direct search and
achieve the result, which are:                                         distributed search approaches will be highlighted.
    1. FA Receiving: System will receive the FA from SQL               A. Implementation
         processing step.
                                                                           The implementation and examinations were carried out on
    2. Select Statement Generator: Calling a generator
                                                                       the Grid Computing Lab, in University Sains Malaysia, 2008.
         method that generates a select statement that will
                                                                       Implementation was applied using java code applied on an
         select from catalogue database locations according to
                                                                       open development platform (Eclipse). Frome the hardware
         the FA.
                                                                       point of view, There were 4 workstations were applied to
    3. Main Server Connection: Calling the connection to
                                                                       conduct the testing of this research and one for the
         the main server.
                                                                       development detailed in Table II.
    4. Sending Generated Select Statement: Send the
         generated select statement to the main server.                 TABLE II.     HARDWARE USED DURING IMPLEMENTATION AND TESTING
    5. Server Location Retrieving: Getting back the site
         information for the server.                                   Machine used for development
    6. Server Connection: Prepare a connection to that                                                     Hard disk        Operating
                                                                       Processor(s)      Memory
         server (site).                                                                                    drive            System
    7. Sending User's SQL: Send the user's SQL statement               Intel ® Core
         to the server.                                                ™ 2 CPU          1GB RAM            80 GB            Mac OS X
    8. Check Data Availability: If the data were found, get            T7200 @                                              Leopard v10.5
         back the result from the server and save it, else,            2.00GHz
         return a message to the system (“No Data Found”).             4 Machines used for testing
    9. Getting Results: Get the result and save to display it                                              Hard disk        Operating
                                                                       Processor(s)      Memory
         to the user.                                                                                      drive            System
                                                                       Intel Pentium 4
                                                                                                                            CentOS
C. Distributed Search                                                  processor 1.8      512 MB           80 GB
                                                                                                                            Rocks
   1. Select Statement Generator: Calling a generator                  GHz
       method that generates a select statement, it will select
       all sites that the table was fragmented to.
   2. Main Server Connection: Calling the connection to                   From the software point of view, Software, libraries and
       the main server.                                                web servers where used are:
   3. Sending Generated Select Statement: Send the                        o Java EE open development platform (Eclipse).
       generated select statement to the main server.                     o MySQL as the DBMS for the data base.
   4. Servers Location Retrieving: Getting back the sites                 o Apache Tomcat 5.5.25 web server. downloaded from:
       information for the servers.                                           (http://tomcat.apache.org/).
   5. Servers Connection: Prepare a connection to all                     o Main libraries: java.sql.connection; java.util.*;
       servers (sites).
   6. Sending User's SQL: Start to send the user's SQL                    In addition, the OGSA-DAI were deployed in the stations.
       statement to the selected servers at the same time.             B. Experimental Designe
   7. Check Data Availability: If the data were found, stop                In order to achieve the objectives of the research, several
       searching, else, return a message to the system (“No            experiments and scenarios has been examined and analyzed.
       Data Found”).                                                   The first group of tests was concerned about comparing the
   8. Saving Result: get back the result from the server and           time execution performance of JDBC beside OGSA, besides
       save it.                                                        the speed up while increasing the database size. The second
   9. Display Result: Display the result to the user.                  group of tests was concerned on the symptomatic of the of
                                                                       fragmentation service system. Moreover, analysis of the
             V.    IMPLEMENTATION AND RESULTS                          experimental results and recommendation will be presented.

   In the following sections, we will present the process flow         C. Performance of JDBC next to OGSA-DAI
or model that the research implementation will be based on.                According to the research framework, several experiments
   The main concern on these experiments is to evaluate the            have been conducted based on two general scenarios of
usability of JDBC connection in low-level manner against the           distributed database retrieval systems. These main scenarios
OGSA-DAI middleware by measuring the time overhead                     are generally under the following headlines:
                                                                            1. Direct Search.



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     2. Distributed Search.                                                      As a conclusion for the previous experiments, results show a
  1) Scenario 1: Direct Search                                                   less time overhead using JDBC connection in comparison to
          In this case, the system will access the data from                     OGSA-DAI.
direct server according to the fragmentation constraint. We                        2) Scenario 2: Distributed Search
based our scenarios on 2 cases:                                                      In this case, the system will send generated query to the
1. Data quantity in the servers.                                                 servers at once, and access the data from all fragmented
2. Server Quantity.                                                              databases. The experiments aims to show the distributed
     The testing was applied using different connection                          search approach among JDBC and OGSA-DAI. We based the
approaches:                                                                      scenarios on the cases of data quantity in the servers.
- Request is sent via JDBC in low level of parsing and                               The testing was applied using different connection
    connecting.                                                                  approaches:
- Request is sent via OGSA-DAI Grid Data Service (GDS)                            • Request is sent via JDBC in low level of parsing and
    to the same relational database.                                                 connecting.
                                                                                  • Request is sent via OGSA-DAI Grid Data Service (GDS)
 (a) Case of Data Quantity                                                           to the same relational database.
    Each query case is being tested while increasing the                             Accordingly, we will start to conduct the phase of data
amount of database rows, and the time for each case is given                     quantity in servers, by increasing the data gradually and test
in Milliseconds (ms).                                                            the given scenarios of query. From here the computational
                                                                                 time for the database retrieving must show differences
                                                                                 between JDBC connection and OGSA-DAI.
                                                                                     Figure 6 illustrates clearly the differences query execution
                                                                                 time using JDBC and OGSA-DAI, which it gives better results
                                                                                 using the JDBC.




    Figure 4. Average query execution time in JDBC and OGSA-DAI

    The previous experiments show a less time overhead on
using JDBC low level connection rather than OGSA-DAI
connection on scalable database size.
                                                                                  Figure 6. Execution time on case of retrieving the entire database from all
(b) Case of Server Quantity                                                                                       servers
    In this case, the experiments are done while increasing the
number of servers and taking the previous average execution                          The second distributed query is being processed among the
time experiment result..                                                         distributed system. The table below shows the experimental
          These results were gained by applying different size                   result of that case.
of database starting from 10 rows up to 50000 rows. The                                    Second query test: “Select * from Table where
average execution time of the query on the multiple amounts                                gender=’M’ ”.
of servers via JDBC and OGSA-DAI is illustrated in Figure 5.
                                                                                                                                                          (1)

                                                                                 In Figure 6, the result is similar comparing with the previous
                                                                                 scenario with slightly small differences. According to the
                                                                                 previous gained results, increasing of speed up in JDBC while
                                                                                 increasing the size of database is clear as shown in the
                                                                                 following figure. The speed up was measured by using the
                                                                                 Formula (1) of speed up.
                                                                                          Figure 7 shows the speed up and the increasing of the
                                                                                 execution time differences between JDBC and OGSA-DAI
 Figure 5. Average query execution time on multiple amounts of servers in        among the servers.
                             direct search




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                                                                                  TABLE III.         FRAGMENTATION SPEED BASED ON FORMULA (3)

                                                                              Data        1 server       2 servers     3 servers        4 servers
                                                                             amount        (local)
                                                                              1000           75            142.5       141.6             141.25

                                                                              5000           95             165        148.3             146.25

                                                                             10000           120            190        156.6              152.5

                                                                             30000           270            215        190                177.5




                                                                                   Figure 8 illustrates the result table (Table III) of the
 Figure 7. Speed up of distributed process using JDBC versus OGSA-DAI        fragmentation among the distributed servers. Well, it’s clear
                                                                             that if performance is taking on account, the fragmentation is
                                                                             not always the right choice. Yet, it gives better speed on the
                                                                             case of increasing the database amount and server amount.
D. Fragmentation Significant
    In this case, the test is going to test the execution on
multiple servers in order to realize the significant of the
fragmentation. In fact, the main goal of these experiments is to
answer the question: “when should we fragment?”
    To answer the earlier question, we need to consider several
formulas to be based on while analyzing the answer.
      If we consider the following variables:
     • Number of servers = ns
     • Time of SQL processing = tsp
     • Time for retrieving one row = tdr
     • Amount of data = ad
     • Direct Search Time = dst                                                      Figure 8. Fragmentation speed on different amount of servers
     • Distributed Search execution time = distst
     • Parallel Process time = ppt                                                According to the fitness case, Figure 9 below shows the
                                                                             scale of fragmentation speed on different amount of servers.
    The total time T for accessing data based on distributed
database according to general approach is represented by the
following formula:

                                                                (2)

    From here, time elapsed without distributing the data (local
search) gives less overhead than if it was subjected to the
distributed system. Accordingly, the execution time for the
distributed search is presented as in the following formula:

                                                                 (3)                     Figure 9. Fragmentation significant based on fitness

Consequently, the fitness case here will event when the time                     From Figure 9 above, it's clear that the fragmentation scale
for local search is equal to the distributed search time                     starts with giving overheads for the system; yet, it shows a
execution for the same amount of data.                                       better performance on the time when increasing the data
    From the second formula, dst search gives 50% less                       amount and the server amount as well.
execution time as an average case than the total of distst                       Figure 9 and analysis table shows quantitative evaluation
average. Base on that, for understanding and analyzing the                   regarding the proposed fragmentation which uses this amount
situations, we presented the following results table that                    of database is not giving much efficient results always. The
illustrates Formula (3).                                                     reason is although the generating method is done on parallel
    By referring to Connolly’s assumptions, that the tsp = 70                and the query sending to the global servers is done on parallel
milliseconds and tdr= 0.005 milliseconds / one row [4]:                      by creating threads, the process spends longer time while
                                                                             generating the obtained methods and creating threads than just



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                                                                                                             ISSN 1947-5500
                                                                          (IJCSIS) International Journal of Computer Science and Information Security,
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retrieving it from one place. Nevertheless, the results also                       distributed system in high-level manner. Moreover, the
demonstrate a better result in the case of huge amount of data                     approaches, which were conducted to examine the distributed
and comparing more than two servers with each other. The                           environment, illustrate the distributed concept among
expected approach to gain a good fragmentation result is to                        fragmentation.
exceed the amount and the size of data, and expanding the                              The main framework has passed through different phases
amount of servers to more than 10 servers will show a better                       to examine the distributed system environment:
result.                                                                                 1. Fragmentation design.
                                                                                        2. SQL optimizing.
E. Direct Search versus Distributed Search
                                                                                        3. In addition, the web-server based approaches to
    The conducted search schema of direct search is giving a                                 demonstrate the work.
good result in big amount of databases. From previous tests,
we can see the average effectiveness that has been found by                            Fragmentation design was based on derived horizontal
using the direct search. Figure 4.13 captures the average of                       fragmentation design in this research, and the experimental
these differences while deploying it using JDBC and using                          results on the retrieval system shows a speed up on the
OGSA-DAI.                                                                          distributed search approach using parallel features instead of
    Figure 10 below shows the speed effectiveness of direct                        using central located database. Moreover, the second approach
search technique. In JDBC case, it shows around 70% faster                         of the direct search shows an efficient execution and less time
than the distributed search and around 50% faster in OGSA-                         consuming for retrieval system than distributing the queries
DAI case.                                                                          among the database.
                                                                                       In the SQL optimizing, the query system shows a good
                                                                                   result on processing the query on basic tested cases, where it
                                                                                   generates directly a query for sending the request according to
                                                                                   the fragmented database.
                                                                                       Accordingly, there is a big relation of distributed
                                                                                   fragmentation design and its impact on the query optimization
                                                                                   for the reason that the SQL processing system will find a
                                                                                   suitable generation method according to the specification of
                                                                                   the fragmented tables.
                                                                                       In the web-server, analytical analysis shows that the
  Figure 10. Effectiveness of using direct search versus distributed search        process under a low-level manner gives a faster speed on
                                                                                   distributed systems than the high-level based connection.
                                                                                       As we can see from the results in the previous chapter, the
F. 4.7 Findings and Recommendations                                                OGSA-DAI gives considerable overheads over the JDBC
From the previous presented experiments, we found that:                            connection in low level. Moreover, the better results are being
1. The time overhead performance differences increases                             gained while increasing the size of database or the number of
   between distributed systems processing using JDBC and                           servers.
   OGSA-DAI while increasing the data quantity or the
   number of servers.
2. Nevertheless, the OGSA-DAI still more secure in the grid                                                  VII. REFERENCES
   environment since it provides message and transparent
   level.                                                                          [1]   Alpdemir1, M. N. Mukherjee, A., Paton1, N. W., Fernandes, A. A. A.,
3. Moreover, unlike the distributed processing using JDBC,                               Watson, P., Glover3, K., Greenhalgh, C., Oinn, T., and Tipney, H.
                                                                                         (2005) Contextualised Workflow Execution in MyGrid P.M.A. Sloot et
   OGSA-DAI is data heterogeneous.                                                       al. (Eds.): EGC, LNCS 3470, pp. 444–453. Springer-Verlag Berlin
4. On the fragmentation side, the distributed system was                                 Heidelberg.
   tested on a 4 servers in where the fragmented database                          [2]   Anjomshoaa, A., Brisard, F., Drescher, M., Fellows, D., Ly, A.,
   where applied there. It will be useful on the event of using                          McGough, S., Pulsipher, D. and Savva, A. (2005) Job Submission
                                                                                         Description Language (JSDL) Specification, Version 1.0 (draft 19),
   a large size of database around more than 10000 in our                                Global Grid Forum 27.
   tests case.                                                                     [3]   Browne, J.C. (2004) “Grid Computing as Applied Distributed
5. Moreover, increasing the database size, gives the                                     Computation: A Graduate Seminar on Internet and Grid
   fragmentation process a positive impact on the                                        Computing“.IEEE international Symposium on Cluster Computing and
   performance.                                                                          the Grid, pp. 239-245.
                                                                                   [4]   Connolly, b. (1999) Distributed System and Database A Practical
                                                                                         Approach to Design, Implementation, and Management.2nd ed.
                          VI.     CONCLUSIONS                                            England: Addison Wesley. pp. 603-638, 645-686.
                                                                                   [5]   Hoarau, W., and Tixeuil, S. (2008) Dependability Evaluation of the
    In this research, we have discussed about the distributed                            OGSA-DAI MiddleWare. Achievements in European Research on Grid
systems and the features of the distributed database design.                             Systems.
Fragmentation and transparency are a main concept of the                           [6]   International Business Machines Corporation. OGSA-DAI Architecture.
                                                                                         [Online]. [Accessed 17 March 2008]. Available from the World Wide




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                                                                                                                  ISSN 1947-5500
                                                                       (IJCSIS) International Journal of Computer Science and Information Security,
                                                                                                                          Vol. 8, No. 9, 2010
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      ccgrid07.lncc.br/docs/posters/27468.pdf                                           Fourth Annual Hawaii International Conference, 8-11 Jan 1991, Kauai,
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                                                                                                                   ISSN 1947-5500

								
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