Rockstar Programmer - Latest Comments

Re: RockStarProgrammer - The Differences Between Mercurial and Git

Samuel — Wed, 20 May 2009 18:53:31 -0000

Users who remain with Mercurial will want to use bitbucket.org, which in my opinion, is one of the best software hosting services ever.

Re: RockStarProgrammer - Good, Fast, Cheap? Eh, No Thanks

colocation — Mon, 27 Apr 2009 07:08:10 -0000

Interesting, I am sure people think loads of servers = bigger business despite the cost and the lack of need for them!

Re: RockStarProgrammer - What Matters in an Asynchronous Job Queue

Stu — Sun, 26 Apr 2009 11:50:39 -0000

Great post. It is stunning how many problems can be solved with a queue, and you hit the key points.

Re: RockStarProgrammer - What's Up? — An XMPP-based Web Monitor

web reader — Mon, 23 Mar 2009 13:27:00 -0000

this comment window is here even if i dont want it - i am unable to see contents of the page i am looking on

http://www.rockstarprogrammer.org/post/2008/jul...

Re: RockStarProgrammer - Git Tag Does the Wrong Thing by Default

Stuart Hughes — Mon, 02 Mar 2009 12:59:38 -0000

Thanks, that helped me out a lot.

Re: RockStarProgrammer - What Matters in an Asynchronous Job Queue

dlsspy — Sat, 21 Feb 2009 00:26:15 -0000

I've not actually used SQS, but from looking in the documentation, it seems that getting a job isn't blocking. I use beanstalkd in places where I need low-latency, so I either have to poll really fast, or ignore my latency requirements.

beanstalkd currently does everything I need and it's quite simple. One file, only libevent as a dependency, and it's currently using less than half a meg of RAM on my box.

Re: RockStarProgrammer - What Matters in an Asynchronous Job Queue

Alex Kane — Fri, 20 Feb 2009 22:52:41 -0000

Use rabbitmq with an ACK or amazon sqs and you'll get what your looking for

Re: RockStarProgrammer - The Differences Between Mercurial and Git

poko — Thu, 01 Jan 2009 08:33:18 -0000

mercurial (v1.1) introduced rebase and git-like local branch support:

http://www.selenic.com/mercurial/wiki/index.cgi...

http://www.selenic.com/mercurial/wiki/index.cgi...

Re: RockStarProgrammer - Stack Overflow is a Time Machine

dlsspy — Sat, 27 Dec 2008 15:34:26 -0000

Yes, I saw it there, and I think I saw the boolean one there, too. They were somewhat popular before that.

Certainly nothing wrong with newbie questions, but if you look at what's most popular over there -- it's that.

But the recommendations of subversion *everywhere* blow my mind. Just last night I saw another one where a guy was recommending subversion to someone because it makes branching so easy. Seriously? Compared to what?

Re: RockStarProgrammer - Stack Overflow is a Time Machine

Calvin Spealman — Sat, 27 Dec 2008 10:41:31 -0000

The array question got on the reddit programming front page, hence the high views.

Re: RockStarProgrammer - Java Singletons Without Locks

dlsspy — Tue, 23 Dec 2008 12:53:41 -0000

Right, so you need to check first.

Consider if the contained object is a thread -- you'll want to try to avoid spinning up a new one, but if you do, you'll nee to tear it down before returning.

In that case, it's get + check + construct + CAS + check + shutdown on race.

Re: RockStarProgrammer - Java Singletons Without Locks

foobar-fred — Tue, 23 Dec 2008 11:32:59 -0000

Drat, the big problem with this implementation is that it instantiats the Singleton class everytime getInstance() is called. No good. Too simple to work.

Re: RockStarProgrammer - Java Singletons Without Locks

foobar-fred — Tue, 23 Dec 2008 11:16:06 -0000

Here is a simplified version. It is too bad that compareAndSet() does not return the new value, but all the same, it may work. Note how getInstance() is not synchronized, but it should be OK if multiple threads are running throught it, I think:

public class Singleton {
private Singleton() {}

private static AtomicReference<Singleton> instance=
new AtomicReference<Singleton>();

public final static Singleton getInstance() {
instance.compareAndSet(null, new Singleton());
return instance.get();
}
}

Re: RockStarProgrammer - Java Singletons Without Locks

dlsspy — Mon, 22 Dec 2008 19:09:57 -0000

I haven't looked at this code in a while. There's at least too much synchronization in it.

I think the fundamental difference between mine and yours is that I try to avoid constructing an object unnecessarily. Just using atomics, it should be easy to do it without ever synchronizing, though.

Re: RockStarProgrammer - Java Singletons Without Locks

foobar-fred — Mon, 22 Dec 2008 18:41:25 -0000

Can you simplify the singleton thus:

import java.util.concurrent.atomic.AtomicReference;
import java.util.Date;

public class Singleton {
public Date d = new Date();
private Singleton() {}

private static AtomicReference<Singleton> instance=
new AtomicReference<Singleton>();

public final static Singleton getInstance() {
instance.compareAndSet(null, new Singleton());
return instance.get();
}

public static void main(String[] args) {
PropsSingleton p = PropsSingleton.getInstance();
System.out.println ("d = " + p.d);
}
}

Re: RockStarProgrammer - The Differences Between Mercurial and Git

Thomas — Thu, 11 Dec 2008 16:51:31 -0000

That depends on how you use it. If you already pushed your comits, rebase against another branch and push it again you've just done it. You will have to force the push though, this is a safety measure.

Re: RockStarProgrammer - Realtime Data with ZK

abhi — Tue, 09 Dec 2008 07:13:49 -0000

how to make grid editable

Re: RockStarProgrammer - The Differences Between Mercurial and Git

AlexMikhalev — Sun, 30 Nov 2008 16:29:39 -0000

May be useful for you - I was looking for github for mercurial and found this
http://www.bitbucket.org/

Re: RockStarProgrammer - Git Tag Does the Wrong Thing by Default

John McCaffrey — Thu, 20 Nov 2008 13:57:21 -0000

thanks, you just saved me some time. I was about to do it the wrong way.

Re: RockStarProgrammer - What Matters in an Asynchronous Job Queue

dlsspy — Wed, 12 Nov 2008 00:14:07 -0000

It's certainly worth talking about.

I'd hate to think about what would have to happen on the inside of memcached to get it performing blocking operations and multiple states of of an item (available, checked out) and automatically changing states based on client events (disconnect -> available), though.

Some of it is certainly backend, but there's a lot of front-end work required to make that work.

Re: RockStarProgrammer - What Matters in an Asynchronous Job Queue

Aaron Stone — Tue, 11 Nov 2008 23:52:26 -0000

Funny thing that just a month later I'd write to the memcached mailing list proposing exactly the use of memcached protocol for a message queue :-)

My thinking is that we can use the binary protocol's extension capability to build the commands of a queue into the binary protocol. The benefit is, as some other commenters have mentioned, to build off the installed base of memcached clients, and to connect with the future development of memcached storage backends -- durability of the server can be achieved with a database backend, for example.

I don't think I want to see a grand unified memcached binary that can do everything, but to have interoperability from a protocol standpoint is very worthwhile, IMHO.

Re: RockStarProgrammer - Good, Fast, Cheap? Eh, No Thanks

dlsspy — Sun, 02 Nov 2008 19:45:57 -0000

Absolutely, and you've done a great job of finding the core of the issue:

What do you want your core competence to be?

For a growing population, computers don't really exist. This is natural progression for UNIX sysadmins, I'm sure the majority of whom have operated at least computer they've never seen before. The only difference is that now we get to operate machines we never can see because they don't *really* exist in any physical form.

Re: RockStarProgrammer - Good, Fast, Cheap? Eh, No Thanks

sdiwakar — Sun, 02 Nov 2008 19:10:57 -0000

I couldn't agree more Dustin!

Being able to sleep at night not having to wonder whether my server has tanked is great for peace of mind - because only then can you really start focussing on the core objective i.e. having a great app :-)

Re: RockStarProgrammer - Good, Fast, Cheap? Eh, No Thanks

dlsspy — Sun, 02 Nov 2008 18:49:21 -0000

I've had a lot of fun with a $20/mo linode instance, even.

I did have first outage with it this morning (my VM crashed or something). However, the stuff I used to have running in-house cost me more than that, and would break quite a bit more frequently. Never having to try to replace hardware in the middle of the night is worth it to me. :)

Re: RockStarProgrammer - Good, Fast, Cheap? Eh, No Thanks

sdiwakar — Sun, 02 Nov 2008 18:31:01 -0000

LOL, its seems as though insecurities about outsourcing aren't restricted to India, Vietnam or the Philippines! I have a good friend who is hosting his application on servers in his garage - the problem is that he's going to have to keep track of the boxes, keep the place dust/fire free etc. monitor uptimes, bandwidth congestion, disk problems, troubleshoot routing problems when they arise, worry about security etc. all without even having starting on the application!

I'd rather pay $50 for a decent quality VPS for the homepage and use EC2/S3 or even Google's AppEngine for the behind the scenes grunt work.