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            <p></p>
            <p>Last week we released a major update to <a href="http://www.radinks.com/upload/">Rad Upload</a>. It's been a long time since the last release (too long to be honest). During that time the browser market placed had changed quite a lot. There were quite a few changes under the hood as well. . Some of those changes, along with changes in the java virtual machine (why hey named it Java 6 update 10 instead of giving it a proper version number is anybody's guess) lead to some irritating inconsistencies.</p>
            <p>One of those annoyances was the proxy detection code breaking. We were in fact using some sun proprietary classes for proxy detection and that's something that's advised against in the API doc. At the time we had no choice cause browsers were reluctant to share proxy server information with applets. Fortunately java 5 onwards a new set of classes were made available that allowed access to proxy info but we never got around to rewriting the Rad Upload code to make use it. Till now that is.</p>
            <p>In the process we also added digest authentication support for proxy servers - something that wasn't available in the previous version. Most proxies that support digest auth will support basic auth as well (what some people call .htaccess authentication but in the case of proxies there isn't an htaccess file (but there usually is an htpasswd file))</p>
            <p>As always most people will be able to get the upgrade free of charge. The full change docs are <a href="http://www.radinks.com/upload/new.php">here ....</a></p>
            <p></p>

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Rad Upload 4.10

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            <p><a href="http://www.gogrid.com">Go Grid</a> is an alternative to <a href="https://aws.amazon.com/ec2/">Amazon EC2</a> and if you go purely by the explanation on the Go Grid website it's cheaper and better than EC2.&nbsp; Certainly there are some areas in which Go Grid is miles ahead of EC2. Their web based control panel is one example. Even a die hard geek can be put off by the EC2 API while even a non tech can probably launch a Go Grid virtual machine thanks to their web interface (but then let us not forget Cloudfront).</p>
            <p>Once you create an Go Grid instance it takes a long time for the virtual machine to actually start up and become usable. That means on demand scaling really isn't on demand. You cannot just create a lot of instances and leave them lying about because you will be billed regardless of whether the instance has booted up or has been shut down.</p>
            <p>Though the pricing comparison on Go Grid website shows their services to be cheaper, that is true only if you are a heavy user. The Go Gridd pricing in the comparison chart is based on their 'Enterprise plan' which has a minimum monthly commitment of USD 2500.&nbsp; Amazon also offers volume discounts so a fair comparison ought to have taken that into account. EC2 discounted prices are as low as $0.03&nbsp; per hour (vs 0.08 per hour on Go Grid)</p>
            <p>Another factor is the Go Grid charges you based on the amount of RAM that you use. While it's possible to start up any server with just 512MB of memory, in practice you are going to need much more. It will be at least 1 GB for linux servers and 2GB for windows servers so you real cost is going to be a lot higher.&nbsp; The CPU on Go Grid packs more power than one on an Amazon Machine Instance (AMI) but CPU is never the bottleneck. The bottleneck is always the RAM , the hard drive or available bandwidth.</p>
            <p>The other day, <a href="amazing-speed-of-amazon-virtual-drives.html">I did a drive speed test on an AMI</a> and found that the virtual drives were amazingly fast. The same test on Go Grid showed wildly fluctuating results 297MB/s to 509KB/s (yes that's right the first one is in mega bytes the second one is in kilo bytes).</p>
            <p></p>
            <div style="margin: 15px; overflow: auto; height: 120px;">
                <p></p>
                <p>[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="cdbfa2a2b98dfffcfafbf5">[email&nbsp;protected]</a>_1_15193_84622 ~]# hdparm -t -T /dev/hda2</p>
                <p>/dev/hda2:</p>
                <p>Timing cached reads: 17024 MB in 1.99 seconds = 8553.32 MB/sec</p>
                <p>Timing buffered disk reads: 530 MB in 3.00 seconds = 176.64 MB/sec</p>
                <p>[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="6d1f0202192d5f5c5a5b55">[email&nbsp;protected]</a>_1_15193_84622 ~]# hdparm -t -T /dev/hda2</p>
                <p>/dev/hda2:</p>
                <p>Timing cached reads: 14944 MB in 1.99 seconds = 7499.96 MB/sec</p>
                <p>Timing buffered disk reads: 2 MB in 4.02 seconds = 509.17 kB/sec</p>
                <p>[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="96e4f9f9e2d6a4a7a1a0ae">[email&nbsp;protected]</a>_1_15193_84622 ~]# hdparm -t -T /dev/hda2</p>
                <p>/dev/hda2:</p>
                <p>Timing cached reads: 12204 MB in 1.99 seconds = 6117.46 MB/sec</p>
                <p>Timing buffered disk reads: 52 MB in 3.02 seconds = 17.23 MB/sec</p>
                <p>[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="b2c0ddddc6f2808385848a">[email&nbsp;protected]</a>_1_15193_84622 ~]# hdparm -t -T /dev/hda2</p>
                <p>/dev/hda2:</p>
                <p>Timing cached reads: 13232 MB in 1.99 seconds = 6634.23 MB/sec</p>
                <p>Timing buffered disk reads: 158 MB in 3.01 seconds = 52.58 MB/sec</p>
                <p>[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="077568687347353630313f">[email&nbsp;protected]</a>_1_15193_84622 ~]# hdparm -t -T /dev/hda2</p>
                <p>/dev/hda2:</p>
                <p>Timing cached reads: 10904 MB in 1.99 seconds = 5468.99 MB/sec</p>
                <p>Timing buffered disk reads: 892 MB in 3.00 seconds = 296.97 MB/sec</p>
            </div>
            <p></p>
            <p>So what's my recommendation: well just try it out yourself, you might end up liking it even though I didn't.&nbsp; Go Grid is giving away a USD 50 coupon at the moment to make it possible for you to do just that without spending any money.<script data-cfasync="false" src="../../cdn-cgi/scripts/5c5dd728/cloudflare-static/email-decode.min.js"></script>
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Go Grid vs Amazon EC2

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            Though people are always coughing up large sums of money, the real bottleneck in both servers and desktop computers is the hard drive. Hard drives find it hard to deliver data as fast as they can be processed. With servers you sometimes find that your network capacity is also used up well before the processor hits 100%. But all that changes with Amazon EC2. The hard drives on Amazon Machine Images is blazing fast. And it isn't even a real hard drive.

            Consider this typical speed test result:
            <p style="padding-left: 30px;"><span style="color: #333333;">[<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="87f5e8e8f3c7e3e8ead2aab6b5aab4b6aab4beaab7b7aab3c6aab5b5">[email&nbsp;protected]</a> ~]# hdparm -t -T /dev/sda2
                    /dev/sda2:
                    Timing cached reads:&nbsp;&nbsp; 874 MB in&nbsp; 2.01 seconds = 434.12 MB/sec</span>
            </p>
            <p style="padding-left: 30px;"><span style="color: #333333;">Timing buffered disk reads:&nbsp; 746 MB in&nbsp; 3.03 seconds = 246.27 MB/sec</span></p>

            As you can see, the drive on the AMI can deliver at 246.27 MB/sec which is at least three times as fast as the drives on my desktop and about 50% faster than a software RAID (<a href="../../linux/drive-speed.php">see here for the result</a>).

            Amazon is truly Amazing

            For the record this test was done with Amazon ec2 small machine instance (instance id: ami-2b5fba42). It doesn't have hdparm by default&nbsp; and it had to be installed with yum. hdparm should be run several times and the average be taken. Detailed test report is below.
            <div style="margin: 12px; overflow: auto; height: 100px;">Test #1:
                [<a href="../../cdn-cgi/l/email-protection" class="__cf_email__" data-cfemail="394b56564d795d56546c14080b140a08140a00140909140d78140b0b">[email&nbsp;protected]</a> ~]# hdparm -t -T /dev/sda2
                /dev/sda2:
                Timing cached reads: 874 MB in 2.01 seconds = 434.12 MB/sec

                Timing buffered disk reads: 746 MB in 3.03 seconds = 246.27 MB/sec

                Test #2:
                Timing cached reads:&nbsp;&nbsp; 900 MB in&nbsp; 2.00 seconds = 449.88 MB/sec
                Timing buffered disk reads:&nbsp; 808 MB in&nbsp; 3.00 seconds = 269.21 MB/sec

                Test #1:
                Timing cached reads:&nbsp;&nbsp; 816 MB in&nbsp; 2.01 seconds = 405.57 MB/sec
                Timing buffered disk reads:&nbsp; 770 MB in&nbsp; 3.02 seconds = 255.39 MB/sec

                On second partition on the same instance (/dev/sda1 ):
                Test #1:
                Timing cached reads:&nbsp;&nbsp; 820 MB in&nbsp; 2.00 seconds = 409.85 MB/sec
                Timing buffered disk reads:&nbsp; 488 MB in&nbsp; 3.00 seconds = 162.51 MB/sec

                Test #2:
                Timing cached reads:&nbsp;&nbsp; 806 MB in&nbsp; 2.01 seconds = 400.77 MB/sec
                Timing buffered disk reads:&nbsp; 716 MB in&nbsp; 3.01 seconds = 237.77 MB/sec

                Test #1:
                Timing cached reads:&nbsp;&nbsp; 908 MB in&nbsp; 2.02 seconds = 449.60 MB/sec
                Timing buffered disk reads:&nbsp; 746 MB in&nbsp; 3.00 seconds = 248.35 MB/sec</div>
            Cached reads average (mean) at 434.12 MB/sec and buffered at 256.96 MB/sec that is more than twice as fast as a Gigabit network card can deliver data

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Amazing speed of Amazon virtual drives

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            <p></p>
            <p>They say, release early, release often and Wordpress is one software that seems to follow that mantra pretty well. Fortunately upgrading from one version of Wordpress to another is a painless task - unless of course you have a customized installation. Upgrading a customized installation can be made easier if you use subversion.</p>
            <p>Normally, in order to upgrade, all you need to do is to delete the old stuff, copy over the set of scripts from the new version and invoke upgrade.php . But if you recursively delete all the old stuff you lose your version control info. So this is my approach to upgrading a customized WP installation which has been subversioned.</p>
            <p>1) copy the files that you have modified into a safe place (themes and plugins will make up the bulk of this)</p>
            <p>2) Download wordpress and unzip it, then change into the source directory and use rsync to copy over the new files while deleting obsolete files from the previous version. the --exclude '.svn' part will ensure that subversion info is not discard. If you are using another revision control system, you can use the appropriate directory here</p>
            <p>rsync . /var/www/raditha/blog/ -avz --exclude '.svn' --delete</p>
            <p>3) Then add new files into the repository with</p>
            <p>svn add `svn stat | grep '^?' | cut -d' ' -f8`</p>
            <p>4) copy back the themes and plugins (inclusive of the .svn folders).</p>
            <p>4) delete the obsolete ones with:</p>
            <p>svn rm `svn stat | grep '^!' | cut -d' ' -f8`</p>
            <p>5) Merging - unfortunately there is no easy recipe for this, you need to manually Kompare , Meld or diff the files to see if your code needs to be merged.</p>
            <p>6) commit.</p>
            <p>7) run upgrade.php</p>
            <p></p>

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Monthly Archives for 2009 03

Rad Upload 4.10

Go Grid vs Amazon EC2

Amazing speed of Amazon virtual drives

Subversioned Wordpress Upgrade