<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p></p>
            <p>On saturday, I noticed that I could no longer check mail on my account. My mail server also has a couple of websites and a mysql database running on it. Those servers apeared to work fine. I opened a remote shell and trying looking through the qmail logs and the syslogs for errors by couldn't find any. Then I decided to forget it for a while cause I had more urgent matters to attend to (mail usually leads to more work anyway). That turned out to be a very bad decision cause soon after that SSH also died.</p>
            <p>In the end I had to ask the web hosting company to restart the server. When it came back up apache was running and the machine could be pinged but SSH, POP, IMAP and SMTP were all dead.Â&nbsp; Without SSH I was dependent on the hosting company to put it right and fortunately their support is excellent. ( It's a small outfit in California calledÂ&nbsp; the <a href="http://www.webquarry.com">Webquarry</a> ). It turned out that one of the two hard drives on the server had just kicked off and died. Because the /home folder was on this drive SSH and the mail servers all stopped responding.</p>
            <p>If /home was the only thing on it, we could have chucked it out and ignored a few emails that have gone missing and be done with it. Unfortunately the drive had some other stuff also on it which meant the OS was barely usable. So a new OS had to be put in (good thing too - it had Fedora Core 6 on it all this while). Then the sites had to be restored from the local copies and last but not least the mail accounts had to be recreated. </p>
            <p>This toast hard drive has tought me several lessons though. The first and most important is that it really is time to move all the static content to Amazon S3 - it not only removes a huge load from the server(s) but also helps to make the hardware last longer; specially the hard drives. Hard drives on servers never get a moments rest and it's no suprise that they burn out.</p>
            <p></p>
            <p></p>

        </div>
    </div>


</body>

</html>

Server Hard Drive Gets toasted

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p></p>
            <p style="text-align: left;">All of a sudden Wordpress refused to let me add a new post. It would take me to the add new page but would almost immediately make an XMLHtttpRequest and after that the TinyMCE editor just breaks up.</p>
            <p></p>

        </div>
    </div>


</body>

</html>

Is that a Wordpress Bug?

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p></p>
            <p>Everyone loves wordpress and everyone hates it's poor performance. The reason that it is so slow is because half a dozen mysql queries are executed for each fragment of a blog post that it displays. So I thought of trying to compress the wp_posts table to find out if it has any impact on performance but before doing that, the speed without compression has to be measured. Here is a typical result (when tested with httperf)</p>
            <p></p>
            <p></p>

        </div>
    </div>


</body>

</html>

WordPress Performance and GZip.

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            Despite a lot of lip service about being supportive of the open source movement Sun is yet to come up with an official release of Java FX for Linux till now.&nbsp; In spite of this JavaFX does show up in the Netbeans plugin installer, but when you try to install it the following error message pops up:
            <p style="text-align: center;"><img class="aligncenter" src="http://images.raditha.com/blog/images/f10/netbeans-javafx.png" alt="some plugins require capability javafx.sdk"></p>

            An widely referred to blog post by <a href="http://www.weiqigao.com/blog/2008/12/11/javafx_0_on_linux_netbeans_plugin.html">Weiqi Gao</a> describes how the OS X version can be used on linux. Unfortunately even after religiously following those instructions it didn't quite work for me. I get this error.
            <p style="text-align: center;"><img class="aligncenter" src="http://images.raditha.com/blog/images/f10/netbeans-javafx2.png" alt="no java fx"></p>

            Looks like I am going to have to do my java fx experiments on my macbook.

        </div>
    </div>


</body>

</html>

JavaFX On Linux.

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p><object data="https://www.youtube.com/v/y9RarK2wUHE&amp;hl=en&amp;fs=1" height="344" type="application/x-shockwave-flash" width="425">
                    <param name="allowFullScreen" value="true">
                    <param name="allowscriptaccess" value="always">
                    <param name="src" value="http://www.youtube.com/v/y9RarK2wUHE&amp;hl=en&amp;fs=1">
                    <param name="allowfullscreen" value="true">
                </object></p>
            <p>What you see here is a speed test carried out using a free tool by <a href="https://www.speedtest.net">Speedtest.net</a>. It's rather predictably named as speedtest mini. At first glance these results are impressive it shows that I have a very fast Local Area Network (184 mbps down and 277 mbps up) but it's a lie. I do have a very fast LAN but this figure is a huge understatement. My LAN is faster. Much much faster. I have gigabite ethernet and the actual speed is at least three times the speed that's reported.</p>
            <p>The result is inaccurate because the test method isn't very scientific. It works by downloading several large files from the web server ( in my case hosted on a server in the LAN). File access is limited by the speed of the hard drives. Unfortunately most hard drives cannot deliver at 100 mbps - the upper limit for gigabit ethernet. <a href="../../linux/drive-speed.php">Hard drives operate much slower</a>.</p>
            <p>For broadband speedtest which is what most people use the tool for - the hard drives will not act as a bottleneck because broadband links typically operate at much much slower speeds and will not place an undue burden on the hard drives (even if multiple users are trying the test concurrently).</p>
            <p>For the upload test, the widget POSTs some data to the server. The data appears to be generated internally or it's uploading a file that it just cached into memory. The result is that the hard drive bottleneck doesn't play such a significant role&nbsp; - at least not for smaller uploads which are held in memory at the server rather than being saved to disk. And speed test doesn't try to upload a lot of data at once anyway because most servers are not equipped to handle a large incoming upload (see this link if you want to learn how to configure your server : <a href="http://www.radinks.com/upload/config.php">http://www.radinks.com/upload/config.php</a></p>
            <p>So how do I know that my LAN really is as fast I as I claim it to be. I used this simple PHP scripts (which mimics a 128MB file being downloaded to test it out)</p>
            <p>$s="0";</p>
            <p>for($i = 0 ; $i &lt; 16 ; $i++)</p>
            <p>{</p>
            <p>$s .= $s;</p>
            <p>}</p>
            <p>for($i = 0 ; $i &lt; 2048 ; $i++)</p>
            <p>{</p>
            <p>echo $s;</p>
            <p>}</p>
            <p>?&gt;</p>
            <p>And this is what wget reported:</p>
            <p>Saving to: `nofile.php'</p>
            <p>[ &lt;=&gt; ] 67,108,864 52.2M/s in 1.2s</p>
            <p>2009-01-04 14:45:13 (52.2 MB/s) - `nofile.php' saved [67108864]</p>
            <p>52.2 MB/s that's already three times as fast as what speedtest reports but this is not accurate either. That's because wget is still saving the file to the local drive (which again acts as the bottleneck). Even that can be avoided by redirecting output to /dev/null/</p>
            <p>wget http://radmedia/speedtest/nofile.php -O /dev/null</p>
            <p>That gives a slightly faster result</p>
            <p>Saving to: `/dev/null'</p>
            <p>[ &lt;=&gt; ] 134,219,776 69.0M/s in 1.9s</p>
            <p>2009-01-04 14:56:25 (69.0 MB/s) - `/dev/null' saved [134219776]</p>
            <p>This result seems a lot more realistic. Yet I am disapointed that it's not close to the 100 MB/s mark which his about the max that you can get with gigabit ether. Do I have so much of noise in my cable to wipe off about 30% of the bandwidth?</p>

        </div>
    </div>


</body>

</html>

LAN Speed Test

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p>Wouldn't it be nice if the monthly archives could be displayed in the form for a chart? Unfortunately there isn't a plugin to do that. Well at least there wasn't one till now. I have just created a very basic plug-in it still needs a bit more work so I am not going to release it just yet. It's made entirely of CSS and javascript and I was inspired to build it after stumbling into this : <a href="http://applestooranges.com/blog/post/css-for-bar-graphs/?id=55">http://applestooranges.com/blog/post/css-for-bar-graphs/?id=55</a></p>

            <p>Right now though the plugin is added to my wordpress installation and it powers the newly created <a href="../archives">archives page</a>. I used to have an archives page earlier while with Movable Type (no there wasn't a chart on it). I couldn't find a way in Wordpress to create the exact same thing so it was not part of the blog till now.</p>

            <p>Having a full archives page means I can shorten the lengthy and ungainly list of monthly archives in the side bar. Some times with short posts the side bars is even 5 times longer in length than the content area (or it used to be that way till now)</p>

            <p>Update May 22, 2014: This site isn't powered by Wordpress now, but the plugin mentioned about vaporized long before that</p>



        </div>
    </div>


</body>

</html>

Wordpress Chart Plugin

<html>

<head></head>

<body>
    <div class="item">
        <div class="item-header">



        </div>

        <div class="item-body">

            <p></p>
            <p>May your projects be completed on time and may they not suffer from scope creep. May the suits realize that you are a hell of a lot smarter than they are.</p>
            <p>I wish you all the best in trying to write bug free code and may your designs be elegant yet simple and may you remember to take backups on time.</p>
            <p>May your social networks grow and it is my wish that your twitter followers mushroom and that you catch all the blogshares idea drops.</p>
            <p>May your ISP be speedy and may your software updates be trouble free.</p>
            <p></p>

        </div>
    </div>


</body>

</html>