AA Project Docs v2.2

5/28/2018 AA Project Docs v2.2

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IS303 Architectural Analysis Project

Re-architecting an Exchanges Web

Application version ! beta " #anuary 0$%&

$! 'bjectiveStudents are required to demonstrate their understanding of concepts related to performance,

availability, scalability, system architecture design, and exhibit practical skills in dealing with these

issues on a Web application. For this project, a prototype Web application is provided, and students

are required to modify its original design and demonstrate the rearchitected solution during the final

presentation to meet certain nonfunctional requirements. !ou will also get an opportunity to revisit

concepts that you have learnt in several "S courses in this project such as ##$%, S&, &", %' and

(omputational )hinking *if you have done that+.

! Project (i)eline

Week $ctivities

-elease of project requirements *this document+.

o -elease of Scoring -ubric

"n class project briefing.

%eploy prototype on individual laptops

(ollection of switches / 0$1 cables from )$.

2 0ab 3 *Setting up a network+

-un prototype in private network

4 0ab *)omcat clustering+.

Set up project with tomcat cluster

$llocation of interim demonstration tasks to teams by )$

5 0ab 2 *0oad testing+.

Start working on your project6interim demo.

-elease of sample test scripts

7 -un project with concurrent users

(ontinue work on interim task and project

8 (ontinue work on interim task and project

-un some load tests, collect some data

9 "n class "nterim demonstration each team is to give a 37 minute demonstration

of its assigned task. *)his demonstration is worth 7: of your final marks.+

;*recess+

"nstructor may meet up with selected teams to check on progress. !ou will benotified if your team gets selected.

"nstructors will let teams select slots for week 2 presentation.


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IS303 AA Project v2.2 (Term 2, 2013/14)

3! (he Story so *ar!our client is a small brickandmortar stock exchange intending to *finally+ extend its trading

operations to the Web. )he &xchange?s inhouse ") department has developed a simple Web

application prototype to demonstrate functionality to management. )he prototype was developed

using @S


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*igure $6 7se 8ase 2iagra)

%!$ ,ie static Web pages

0ike most Web sites, the &xchange provides several informational C)'0 pages to all visitors.

(heck out the C)'0 pages in the staticpagesfolder of the prototype Web application. )here are

a variety of C)'0 pages available of different siDes. Some of these pages are huge that may take

a long time to appear in the client?s browser. !ou should preserve how these static pages look

like since they have already been approved by the &xchange?s management. $nyone can view

static pagesE there is no need for authentication. *)hese static pages can be viewed using

http6//9hostIP6port:/Prototype/staticpages/9page;na)e:!ht)l after you have successfully

hosted the prototype.+

%! ,ie current prices

0ike static pages, anyone can view this page without logging in. Aut unlike static pages, this page

shows, for each stock, the last price, the current *highest+ bid price and the current *lowest+ ask

price. )his means that every time this page is refreshed in the browser, it may show different

figures as new buy6sell orders come in. *)his current prices page can be viewed using

http6//9hostIP6port:/Prototype/current!jsp after you have successfully hosted the prototype.+

%!3 .og in/out

Bsers with accounts with the &xchange are able to log into the Web site and log off. When clients

log in to perform a buy or sell operation, they provide a user "% and a password. )o keep things

simple, for this project, there is no need to check if the user "%s and passwords are correctE you

can simply assume that the user "%s and passwords provided are always correct. *)he login

page can be viewed using http6//9hostIP6port:/Prototype/login!jsp after you have successfully

hosted the prototype.+ "f a user attempts to view a protectedG page such as buy!jspor sell!jsp

directly by keying in the full B-0 to these pages, he may be redirected to login!jspif he hasn?t

been authenticated yet.

3


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%!% uy shares

#nly users who have logged in *i.e. authenticated users+ are able to buy shares. Shares are

always transacted in lots of 333 shares at this &xchange, and you can assume that the unit

share price ranges only between H and H33 *including H and H33, with no cents+. When a

user buys shares, the following information is important and needs to be sent to your Web

application the buyer?s user "%, the stock "%, the bid price for each share, and the date6time

stamp of this request. Auyers cannot retract their buy orders once they have sent one in, and all

buy orders will always be for 333 shares *rather than a multiple of 333+. &ach buy order will be

queued in the Web application until it matches a sell order. $t the end of the trading day, all

unmatched buy orders will be discarded. Since this is a small &xchange, there are only 4 types of

shares to buy S'B, 1BS and 1)B.

*)he buy shares page can be viewed using http6//9hostIP6port:/Prototype/buy!jsp after you

have successfully hosted the prototype.+

Aecause settlement of trades *i.e. payment for purchase+ is only done the following day, all

purchasesG are made on credit. )he exchange imposes a credit limit of H,333,333 per user

which is reset at the beginning of each trading day. When a user enters a buy order, your system

must ensure that the buyer?s daily credit limit is not breached. "f so, the buyer?s buy order is

ignored and is not even placed into the queue. For example, a particular buyer has submitted 25

buy orders of 333 S'B shares each at H53 per share. Ce has hence used upG H=83,333 of his

credit, and is left with only H53,333 of credit for buy orders for the day. Ce then submits another

buy order for another lot of S'B shares at a bid price of H73 per share *or H73,333 for 333

shares+. Bnfortunately in this scenario, the system should not allow this new buy order to be

submitted regardless of whether the previous 25 buy orders have been fulfilled, because thebuyer?s credit limit of H,333,333 will be breached if the last buy order goes through. Aesides

showing the user an error message to notify him that his buy order cannot be processed, such

buy orders need to be logged in a log file *rejecte2!log+.

%!< Sell shares

#nly users who have logged in successfully *i.e. authenticated users+ are able to sell shares.

Shares are always transacted lots of 333 shares at this &xchange, and the unit share priceranges between H and H33 *including H and H33+. When a user enters a sell order, the

following information is important and needs to be sent to your Web application the seller?s user

"%, the stock "%, the ask price for each share, and the date6time stamp of this request. Sellers

cannot retract their sell orders once they have made a sell order. &ach sell order will be queued in

the Web application until it matches a buy order. $t the end of the trading day, all unmatched sell

orders will be discarded.

*)he sell shares page can be viewed using http6//9hostIP6port:/Prototype/sell!jsp after you

have successfully hosted the prototype.+

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)he ask price is the lowest price a seller of a stock is willing to accept for a share of that given

stock. #n the other hand, the bid price is the highest price a buyer of a stock is willing to pay for a

share of that given stock. )he currentG bid price is the highest bid price in the queue so far, and

the currentG ask price is the lowest ask price in the queue. "n order to match the hordes of buy

and sell orders, the exchange starts with the highest bid and try to match it up with the lowest ask.

"f there is a match, the transaction occurs at either the current ask or current bid price dependingon whether it is a selling trade or a buying trade. $ buying tradeG occurs when a match happens

because of a new buying order. "n a buying tradeG, the transaction price is the current ask price.

$ selling tradeG occurs when a match happens because of a new selling order. "n a selling

tradeG, the transaction price is the current bid price.

Cere is an example to illustrate these rules for a particular stock

)ime

$ction "n the buy queue "n the sell queue (urrent*highest+bid

(urrent*lowest+ask

0ast price

3 $ makes a buy order for 333 shares of

S'B at bid price of H36share

$ *H36share, tI3+ H3 16$ 16$

A makes a buy order for 333 shares ofS'B at bid price of H6share

$ *H36share, tI3+A *H6share, tI+

H 16$ 16$

2 ( makes a sel l order for 333 shares ofS'B at ask price of H26share.*no match+


(*H26share, tI2+ H H2 16$

4 % makes a sel l order for 333 shares ofS'B at ask price of H;6share.*match between % and A. )his is a sellingtrade, and the transaction happens at thecurrent bid price+


(*H26share, tI2+%*H;6share, tI4+

H3 H2 H

5 & makes a sel l order for 333 shares ofS'B at ask price of H26share.*no match+

$ *H36share, tI3+ (*H26share, tI2+&*H26share, tI5+

H3 H2 H

7 F makes a buy order for 333 shares ofS'B at bid price of H26share.*match between F and (. )his is a buyingtrade, and the transaction happens at the

current ask price. 1ote that even though (and & are both asking for H26share, (gets matched first because of its earliertime stamp.+

$ *H36share, tI3+F *H26share, tI7+

(*H26share, tI2+&*H26share, tI5+

H3 H2 H2

)he current prices page should always reflect the correct last, current bid and current ask prices

for each stock. !ou can refer to the following Web pages for a description of the technical termsG

for trading

http66daytrading.about.com6od6daytradingbasics6a6'arket


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*iii+ !our application sends information about the transaction *as in your log file+ to a

remote Aack #ffice Server. !our application communicates with the Aack #ffice

Server using J'0 Web services. Study the prototype to determine how this is done.

)he Aack #ffice Server will then contact the seller and buyer via email and snail mail about their

successful transaction, and perform the necessary followup activities *such as collecting payment

from the buyer and paying the seller, adjusting their balances with the (entral %epository etc+.

)his Aack #ffice Server is 1#) part of your system, but provided as a service by another vendor,

so you do not need to know how it does its job. "t is of course important that the transaction

information received by the Aack #ffice Server tallies with the information in your log file.

%!4 ,ie 7n+ul+ille2 'r2ers

)his page is used primarily for debugging and troubleshooting. "t shows the list of queued *i.e.

unfulfilled buy and sell orders for each of the 4 stocks+, as well as the credit limit of each user "%.

%o ensure that this Web page works and reflects correctly the current stateG of your system. *)he

view unfulfilled orders page can be viewed using

http6//9hostIP6port:/Prototype/vie'r2ers!jsp after you have successfully hosted the

prototype.+

%!5 En2 (ra2ing =ay

)his page is used to simulate the end of a trading day. Aasically when this page is accessed, the

system cleans upG and prepares for the next trading day. For example, unfulfilled buy and sell

requests are discarded as part of the cleaning upG process, and the last pricesG of each stock is

reinitialiDed. *)he &nd )rading %ay page can be viewed using

http6//9hostIP6port:/Prototype/en2(ra2ing=ay!jsp after you have successfully hosted the

prototype.+

.


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1etAeanshttp66netbeans.org6downloadsor any other @ava "%& *)he prototype application

has been tested with 1etAeans 9.2 and )omcat 9.3.28 that comes with 1etAeans.+ K %o not

run your experiments6demo using 1etAeansL

)omcat Web Server *"mportant note during your demonstration, you should 1#) be hosting

your application on )omcat that comes with 1etbeans, but on an independent )omcat server."n other words, your Web application should be running without your "%& open during your

demonstration.+

Misual Studio.1&) 232 Bltimate edition *from %reamSpark+ to perform simulated client tests

*For teams preferring to use @'eter to perform load testing+ @'eter

http66jmeter.apache.org6downloadNjmeter.cgi . )here are a few useful tutorial videos on

!ou)ube about @'eter as well.

1! >our (as!our team?s task is to study the prototype provided and to either modify it or build from scratch a new

Web application to meet the nonfunctional requirements described below. %o not modify the

functionalities and lookandfeel of the Web pages in the prototype as they have already been

approved by the &xchange?s management.

!our final liveG implementation will need to cater for

. *ault tolerance. )he prototype runs on a single physical server, which means that if that

server goes down, your whole application goes down. !ou need to design your system so

that your entire Web site does not depend on the availability of a single server only. "f you

want to set up a cluster for your servers, any client should not be awareG of any failure in yourcluster *except for perhaps, a longer response time+.

*i+ )hink about the various situations in which one of the servers fail *sudden loss of power,

disconnected from the network etc.+ and how your system will react to each of these

scenarios. !ou can simulate some of these failures during your demonstration.

*ii+ "s it possible to automate a server restart in each case of failureO "t will be great if you can

demonstrate a system with automated and seamless failover *the client will not be aware

of any failures, and the system administrator will not need to intervene manually, and

there should be a log file showing erroneous conditions that can be analyDed

subsequently+.

*iii+ "s there any single point of failure *S


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*remember to preserve the functionality and lookandfeel+. )here are three categories of

pages that should run faster

*i+ -esponse time of the various static pages*ii+ -esponse time of the current priceG page*iii+ -esponse time for the buy share and sell share pages

4. ?igh (hroughput. $s a market exchange, volume is as important as response time. !our

application should be able to handle a significant number of concurrent requests. Bse your

load tester to measure the rate at which your application accepts and processes incoming

buy6sell orders. 1ote that response times *discussed above+ and throughput may be inter

dependent K be aware of and discuss any tradeoffs involved.

5. ?ori@ontal scalability. !our Web application is expected to be easily scalable as the number

of online users increase over time. !our team is expected only to focus on horiDontal

scalability *scaling by adding more servers+, and not on vertical scalability *scaling by adding

more physical resources to each machine such as -$'+.

7. Reliance on an external syste). !our Web application communicates with an external Web

service provided by your Aack #ffice Server partner. )here is no guarantee that this Web

service will be always upE in fact, your team has been warned that this communications

gateway does suffer from periodic unscheduled downtime as your partner struggles with

capacity issues. !our team has to make a decision as to what should be done in the event

that your application is unable to communicate with the Aack #ffice Server during a send to

back officeG operation.

Whatever the case, it is very important that the figuresG balance in the sense that all the

transaction information is correctly sent over. )hat is, you need to ensure that by the end of

each trading day, all the transactions in your log file match the information sent over to the

Aack #ffice Server. $fter all, clients will be very unhappy if they are not informed if theirbuy6sell bid went through *-ecall that there were some system hiccups during Facebook?s

"


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*i+ $ll buying orders and selling orders that have been successfully sent to the server are

taken into consideration. 1o orders should be lostG. For example

total number of buying orders successfully sent to the server Itotal number of buying orders in your unfulfilled buying order list Pnumber of matched transactions *as recorded in your )atche2!logfile+ P

number of rejected buy orders *recorded in your rejecte2!logfile+.

*ii+ )he credit limit of each user should never be breached at any time during a buyG.

*iii+ When a series of buy and sell orders are placed in slow sequence, they should result

in a fixed stable state *for example, if the series of requests in the table in section 5.7

are played out in a simulation using a load tester, the outcome of current!jsp,

)atche2!logand rejecte2!logshould be predictable and consistent.

*iv+ $t the end of the trading day, the contents of )atche2!logand the information sent

to the Aack #ffice system are consistent.

"t is very important to think about how each of these goals can be achieved if you have aclustered environment. Malidate empirically *using load tests+ that your system produces the

same results when clustered and when running singly.

9. 'thers! "t is very important that you are able to demonstrate that you have achieved

improvement in the abovementioned nonfunctional attributes in a scientific and rigorous

manner. For example, you need to show C#W you detected that the average response time

to a particular static page has decreased for the same client load, with figures to support your

claim. (redit will also be given to teams which can improve the other aspects of *i+

maintainability, *ii+ manageability and *iii+ extensibility of your Web application.

!ou should apply the theoretical concepts taught in the course, and find out how scalability,

availability and performance can be improved in a real enterprise system *these may not be covered

in the course+. Sometimes decisions about tradeoffs will need to be made for example, between

performance and availability. 1o marks will be awarded for effort spent on beautifying the user

interface *i.e. Web pages+. !ou should focus on the nonfunctional aspects instead.

1ote we have decided to exclude the *very important+ nonfunctional attribute of securityfrom your

scope. For example, there is also no need to encrypt communications between clients and the

exchange server using SS0 *this is also always done for such Web applications involving financial

liability+. Security is often antagonistic to other nonfunctional attributes *for example, running the Web

application over SS0 improves security by encrypting all the data transmitted over the network, but

inevitably decreases performance+. For this project, you can ignore the security aspect of your Web

application and focus on the other quality attributes. Aut do be aware that in real enterprise

applications, security is often one of the most important quality attributes and often takes precedence

over performance, availability and scalability.

4! Rules

. !our final Web application implementation should be based on @S


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technologies. So if your team wishes to select a different platform *e.g. $S< instead of @S


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&ach team will be given 4< )inutesfor your final presentation, questions and demonstration.

!ou !ll "!#$ t%!& t!'%t. Ae sure to arrive early to setup and be ready.

1ote that no servers will be provided for your demonstrations which means that you will need to host

your solution on your own laptops. $s previously noted, you do not gain additional points for

demonstrating a short response time, but you need to demonstrate a SC#-)&- response time

compared to the original prototype under same network conditions. !ou do 1#) get points for

improving response time by decreasing network latency *for example, using a private wired 0$1 over

wireless 0$1+, but you do gain points by showing that certain code or architectural changes have

decreased response time of clients viewing your Web pages.

! =eliverables)he following are to be submitted in a BSA portable drive $) )C& S)$-) of your final presentation

*we will return your drive after copying the contents+

. $ 2eploy)ent 2iagra)showing how your solution is hosted, with short notes justifying your

deployment decisions, if necessary.

2. Full source co2eof your working system.


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*igure 6 Sub)ission +or)at

)eams will be penaliDed for missing deliverables or failure to prepare the deliverables as required

*e.g. wrong folder names+.

$0! Bra2ing)his project comprises 30Cof your final score for this course *7: for interim demonstration, 27: for

final presentation6demonstration6submission+. "t is important that all team members contribute fairly to

the project. $ll team members should expect to be asked questions about the experiments and

system.

)he peer review form allows students to grade fellow team members on quality of work contributed,

quantity of work contributed, technical expertise and general contribution. )he peer review results will

be used to identify outstanding and undercontributing team members within the team, and can be

used to vary individual scores for the project. 1evertheless, teams are encouraged to surface teaming

issues earlier on in the semester to instructors so that they can be monitored early and resolved.

10.1 Interim demonstration:

!ou will receive a score between 3 and 7 based on your demonstration. Rrading rubric

Score

%escription

3 )eam is still in lalaland.

0ittle work has been done, but we pity you enough not to award a Dero.

2 Some work has been done, but team has difficulties getting the basic setup right.

4 )eam has completed a major part of the assigned task, and answered some of thequestions in their task description with empirical evidence.

5 -esults are presented in a clear and systematic manner. )eam has completed theassigned task, and has answered most of the questions with empirical evidence.

7 )eam has demonstrated good overall investigative skills and done a significantamount of experimental work to answer the questions in the task description.

10.2 Final Presentation:

)he following list is detailed in the grading sheet, posted separately. $ filled outgrading

sheet must be brought to the final presentation.

%eliverables 7: quality of code, material, all required files and documents included

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Fault )olerance 43: any single points of failureO Cow fast is failoverO "s restart

simple and easyO

Cigh


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Appen2ix A6 Running the Prototype)he prototype can be easily executed and edited using 1etbeans 9.2 *with $pache )omcat 9.2.29+,

although you are free to use any other @ava "%& you prefer.

#btain the prototype.Dip file from e0earn, and unDip it to your hard disk

"f you have 1etbeans 9.2, select, File#pen


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Appen2ix 6 So)e 7se+ul Re+erences

"S434 0ab (overs clustering of 2 )omcat servers using modNjk

"S434 0ab 2 (overs load testing of a Web application using Misual Studio )eam System

'y ST0 (luster http66dev.mysql.com6downloads6cluster69.3.html*"f you intend to perform

database server clustering using 'yST0, you will need to get the 'yST0 (luster editionE the

(ommunity Server edition does not support clustering.+

Bseful book on 'yST0 (lustering ?igh Per+or)ance DyS.G *2ndedition+ by SchwartD,

Uaitsev, )kachenko, Uawodny, 0entD and Aalling. S'B students have access to the online

version of this book via the S'B library Website.

$ brief overview of )omcat clustering *what are sticky sessionsO What is session replicationO+

http66www.easywayserver.com6tomcatclustering.htm

)wo quick writeups about general conceptshttp66www.datadisk.co.uk6htmlNdocs6javaNapp6tomcat86tomcat8Nclustering.htmandhttp66www.vicconsult.com6tips6apachetomcatloadbalancesessionreplication.html

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http://dev.mysql.com/downloads/cluster/7.0.htmlhttp://library.smu.edu.sg/http://library.smu.edu.sg/http://www.easywayserver.com/tomcat-clustering.htmhttp://www.datadisk.co.uk/html_docs/java_app/tomcat6/tomcat6_clustering.htmhttp://www.datadisk.co.uk/html_docs/java_app/tomcat6/tomcat6_clustering.htmhttp://www.vicconsult.com/tips/apache-tomcat-load-balance-session-replication.htmlhttp://dev.mysql.com/downloads/cluster/7.0.htmlhttp://library.smu.edu.sg/http://www.easywayserver.com/tomcat-clustering.htmhttp://www.datadisk.co.uk/html_docs/java_app/tomcat6/tomcat6_clustering.htmhttp://www.vicconsult.com/tips/apache-tomcat-load-balance-session-replication.html


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Appen2ix 86 Presentation 8heclist

o $ll deliverables in section = placed on thumb drive before presentation

o Slides showing response time include variance *points awarded for including, and deducted if

missing+

o (ode for transaction matching and for back office opened in development environment for

instructors to view it.

o 0oad test, including buys6sells, ready to run *Vusers K should not create errorsE time 43 minE

bids6asks should be random+

o %atabase set and ready to go

o

Documents

AA Project Docs v2.2