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Thu May 23 22:45:24 HKT 2019

design



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Tue Feb 08 00:38:32 HKT 2011 From /weblog/design/distribute

GridGain


Implement ping-pong play between two nodes on the cloud using GridGain Distributed Actors - http://gridgaintech.wordpress.com[..]11/01/26/distributed-actors-in-gridgain/

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Sun Jan 16 01:51:29 HKT 2011 From /weblog/design

testable


http://misko.hevery.com/code-reviewers-guide/

Discussion on TDD algorithm - http://css.dzone.com/articles/tdd-algorithms

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Tue Dec 14 00:57:34 HKT 2010 From /weblog/design

language


Issues of annotation dependence test framework, usually new language feature come out to solve some problem people get excited. However people found that the problem it bring are not less than the problem it solve, it take time to proof the value - http://jroller.com[..]tmotion?entry=annotations_suck_a_lot_and

Compare OO feature of difference language - http://www.derangedcoder.net[..]ral/comparingObjectOrientedFeatures.html

Comparing C# and Java - http://www.25hoursaday.com/CsharpVsJava.html

Discussion about extending standard API - http://www.codinghorror.com/blog/archives/001151.html

Few good suggestion when thinking of design a language, Consider using ML, Don't be afraid of being the same - http://www.plsadventures.com[..]programming-language-design-is-hard.html

Design Principles Behind Smalltalk, see how idea of inheriance, polymorphism originated - http://web.archive.org[..]/design_principles_behind_smalltalk.html

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Thu Dec 09 02:55:30 HKT 2010 From /weblog/design

hashing


http://computinglife.wordpress.com[..]why-do-hash-functions-use-prime-numbers/
http://www.azillionmonkeys.com/qed/hash.html

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Thu Mar 25 02:07:15 HKT 2010 From /weblog/design

date


Date handling look simple but easy to fail in trap. Even worst is this is easy to have bad data which hard to fix. Here is an example - http://blogs.msdn.com/jensenh/archive/2005/11/23/496246.aspx

One tip for testing application with time dependence, treat it as random - http://googletesting.blogspot.com[..]pot.com/2008/04/tott-time-is-random.html

Explanation of issues of Joda-time, basically it still haven't map the human view of time close enough than machine view of time - http://www.jroller.com/scolebourne/entry/why_jsr_310_isn_t

Screencast of how to driven a fluent Date API - http://tedyoung.blogsome.com[..]-apis-in-java-episode-1-comparing-dates/

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Tue Feb 02 12:03:55 HKT 2010 From /weblog/design

indexing


twelve things you should know about indexing - http://www.ademero.com[..]elve-things-you-should-know/indexing.php

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Thu Jan 21 01:46:26 HKT 2010 From /weblog/design/IoC

Inversion of Control


When these containers talk about how they are so useful because they implement "Inversion of Control" I end up very puzzled. Inversion of control is a common characteristic of frameworks, so saying that these lightweight containers are special because they use inversion of control is like saying my car is special because it has wheels.

http://www.martinfowler.com[..]ticles/injection.html#InversionOfControl

This guy think IoC is going to use is more and more place as GC. However, I will think quit a lot of time IoC is use incorrectly, somebody even try to use it everywhere and replacing constructor... - http://howardlewisship.com[..]endency-injection-mirror-of-garbage.html

IMHO jetty is the first widely used program about IoC idea, even before spring - http://kasparov.skife.org/blog/2004/08/30/

Explain when IoC is overkill - http://blog.objectmentor.com[..]010/01/17/dependency-injection-inversion

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Thu Jan 14 19:13:15 HKT 2010 From /weblog/design

aspect


Article with example to show how aspect can help in most common case - http://www.infoq.com/articles/aspects-of-domain-model-mgmt

http://veerasundar.com[..]se-cases-of-aspect-oriented-programming/

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Wed Jan 06 01:47:53 HKT 2010 From /weblog/design

version


A Theory of Compatible Versions, and introduction of how and why difference versions are comptible or not - http://www.xml.com/lpt/a/1684

XStream offers some support for refactorings (aliases can help). But very soon you will run into big troubles and will have to make some decisions. Either avoid refactorings (just a little tweak here and there, will weaken your architecture over time) or start implementing workarounds – e.g. custom converters (much work, bad code). - http://blog.cedarsoft.com[..]ts-wrong-with-xstream-and-similar-tools/

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Thu Dec 31 00:46:40 HKT 2009 From /weblog/design/interview

Rod Johnson


Lessons Learned From Java EE’s Evolution, discuss about value of standard and opensource - http://www.infoq.com/presentations/Lessons-Learned-from-Java-EE

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Sat Dec 12 10:43:54 HKT 2009 From /weblog/design

login


Batch login Authentication - http://www.udidahan.com[..]us-high-performance-login-for-web-farms/

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Thu Dec 10 00:01:54 HKT 2009 From /weblog/design/interview

Ralph Johnson


http://www.infoq.com[..]h-Johnson-Parallel-Programming-Patterns#

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Fri Nov 27 15:56:17 HKT 2009 From /weblog/design/distribute

eventual-consistency


A short example to show how eventual-consistency work - http://sbtourist.blogspot.com[..]/11/eventual-consistency-by-example.html

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Thu Nov 12 09:57:25 HKT 2009 From /weblog/design/pattern

repository


http://giorgiosironi.blogspot.com/2009/10/repository-pattern.html

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Fri Sep 25 19:04:28 HKT 2009 From /weblog/design

mutability


http://en.wikipedia.org/wiki/Const
http://www.c2.com/cgi/wiki?ValueObjectsShouldBeImmutable
http://www.markhneedham.com[..]09/16/coding-watch-out-for-mutable-code/
Discuss issue of mutability from another aspect - http://www.artima.com/articles/hickey_on_time.html

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Thu Sep 24 12:35:05 HKT 2009 From /weblog/design

failfast


Have read this article long time before: http://www.martinfowler.com/ieeeSoftware/failFast.pdf However, the more I work on programming the more I find that reasonable default (may be with logging) work better in some cases, but really need to beware about the cost of debugging if there is problem....

Another discussion about failfast vs. failsafe - http://www.certpal.com[..]009/09/iterators-fail-fast-vs-fail-safe/

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Sat Sep 19 01:37:37 HKT 2009 From /weblog/design

concept


http://www.butunclebob.com[..].UncleBob.ArchitectureIsaSecondaryEffect

sunday-school truth: if you don't do well in small think, you will do worse at big thing: http://udidahan.weblogs.us/archives/035032.html

Wait for best solution - http://www.threeriversinstitute.org/blog/?p=374

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Sun Sep 13 00:05:27 HKT 2009 From /weblog/design

delete


I think there's perfectly reasonable scenarios for both soft and hard deletes, with and without audit trails.

1. Soft delete:
A user signs off of your service, but you need to keep (anonymized) stats data consistent for your customers - here you cannot remove the entire user, you just blank his personal data (name, email, phone, ...) and keep the anonymized statistical data (country, birth year, profession).

2. Soft (or super-soft) delete with audit trail:
Any financial transaction data, even if entered by error, may only be corrected by adding a correction entry, not by deleting the erroneous entry, or the IRS will be all over you. So either you flag it as deleted (soft delete) or you correct it by adding another entry ("super-soft delete").

3. Hard delete with audit trail:
A user unsubscribes from your newsletter. No need to keep the info "he once was subscribed to it" in the live database, but need to keep the info somewhere accessible in case he sues you for spamming and you can prove "but back in August when you got the mail, you were still subscribed".

4. Hard delete with no audit trail:
Personal data as in #1 if your local data protection laws require. (This means *no* more storing, *anywhere*, technically speaking not even in last month's backup, but that's another issue altogether.)

http://ayende.com/Blog/archive/2009/08/30/avoid-soft-deletes.aspx

And Udi think is real life, people usually never really delete something - http://www.udidahan.com/2009/09/01/dont-delete-just-dont/

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Thu Sep 03 00:28:22 HKT 2009 From /weblog/design

composition over inheritance


Good example of composition over inheritance - http://www.javablogging.com/comparable-vs-comparator/

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Mon Jan 12 23:05:43 HKT 2009 From /weblog/design

messaging


Why should you combine Reliable Messaging with Distributed Caching - http://www.theserverside.com[..]MessagingDistributedCaching/article.html

Read from cache, write the message system - http://radio.weblogs.com/0112098/2003/01/15.html#a319

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Wed Jun 25 09:59:02 HKT 2008 From /weblog/design/exception

problem of using exception for control flow


Other than harder to read, this approach is easier to have side effect, consider the following case:

// Code which fail
public String service() {
try {
// a lot of other code....
return getRecord();
} catch (SQLException re) {
return "defaultRecord";
}
}

private String getRecord() throws SQLException {
PreparedStatement ps = getConnection().prepareStatement("select something from sometable");
try {
final ResultSet rs = ps.executeQuery();
try {
if (rs.next())
return rs.getString(1);
else
throw new NotFoundException();
} finally {
rs.close();
}
} finally {
ps.close();
}

// definition of NotFoundException, analog to IOException and FileNotFoundException
public final class NotFoundException extends SQLException {....}


The idea is, for any database problem, just return default value. However, if someone change the interface of NotFoundException to

public final class NotFoundException extends RuntimeException {....}

Then it break service() silencely :-/ Some to it is better to have


// Code which fail
public String service() {
try {
// a lot of other code....
return getRecord() == null ? "defaultRecord" : getRecord();
} catch (SQLException re) {
// proper exception handling
}
}

private String getRecord() throws SQLException {
PreparedStatement ps = getConnection().prepareStatement("select something from sometable");
try {
final ResultSet rs = ps.executeQuery();
try {
if (rs.next())
return rs.getString(1);
else
return null;
} finally {
rs.close();
}
} finally {
ps.close();
}



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Tue May 06 14:25:04 HKT 2008 From /weblog/design/interview

Donald Knuth


Donald Knuth on Multi-Core, Unit Testing, Literate Programming, and XP:

I also must confess to a strong bias against the fashion for reusable code. To me, "re-editable code" is much, much better than an untouchable black box or toolkit. I could go on and on about this. If you’re totally convinced that reusable code is wonderful, I probably won’t be able to sway you anyway, but you’ll never convince me that reusable code isn’t mostly a menace...


http://www.artima.com/forums/flat.jsp?forum=276&thread=229705

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Tue Apr 29 01:46:55 HKT 2008 From /weblog/design/interview

Bjarne Stroustrup


Nice message cover DSL, IDE, multiple dispatch, message passing, and more

http://msdn2.microsoft.com/en-us/magazine/cc500572.aspx

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