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Posts from the ‘Technology’ Category

21
Dec

The New and Improved Mozy for Mac 1.6

Of course, it can’t really be both new and improved. Logically, it has to be one or the other. It’s just that I’m excited about the 1.6 release of Mozy’s Mac client. It was finished last week and the response has been very positive.

It seems that with #Mozy for #Mac 1.6 it’s finally reliable. Awesome! — @donut2d

Latest Mozy update (1.6) on Mac OS X is a major improvement – it actually works, and doesn’t suck out all of your RAM. — @mmetcalfe

Our last few releases, while making improvements in many areas, seemed to have lingering and subtle problems. With the 1.6 version, we hope to have finally put them behind us.

We turned on auto-update today. If Mozy hasn’t updated itself yet, please feel free to grab the latest version of MozyHome (or MozyPro) and let us know what you think.

Official List of Changes

You can see the official list at the pages linked above. Mozy only makes the list of changes available for the current release, so I’ve copied them here for the future. You can see the changes in Mozy for Mac 1.4 and Mozy for Mac 1.5 too.

Enhancements

  • Removed dependency on Spotlight since Spotlight queries are unreliable under certain circumstances
  • Changes to backup selections are now saved automatically
  • Reduced memory usage
  • Decrease size of SupportFiles.zip file
  • Improved the performance of the Configuration window
  • Improved support for Snow Leopard and fixed issues caused by Snow Leopard’s 64-bit architecture
  • Improved interaction between Mozy’s preferences and Snow Leopard; Mozy’s preferences no longer require System Preferences to be re-started
  • Improved the use of temporary files
  • Improved reports in Admin Console for Pro users
  • Improved support of our external drive feature by addressing edge cases that can cause stability issues
  • Improved feedback when setting a preference to an invalid value
  • Improved error handling when an auto-update fails to download successfully
  • Added support for nine non-English languages
  • Added the ability to delete a Backup Set using the keyboard
  • Added the ability to undo and redo configuration changes
  • Added the ability to sort Backup Sets by file count or total size
  • Added history information to main Configuration window
  • Added “Install updates automatically” checkbox to dialog which prompts user to upgrade
  • Added ability to manually check for an update
  • Added ability to back up network drives using the NFS protocol for Pro users

Bug Fixes

  • Fixed issues which caused the “Show status in menu bar” preference to not work properly
  • Fixed the link in the Readme file for downloading the software
  • Fixed a computer name display issue in the Setup Assistant
  • Fixed an issue causing the Configuration window to crash when browsing a folder with lots of files
  • Fixed an issue which caused the file exclusion warning to not show up properly
  • Fixed an issue which caused network connection errors
  • Fixed an issue which caused several duplicate warning dialogs to appear
  • Fixed an issue which prevented the use of certain non-Roman characters in a password
  • Fixed an issue which caused a file to be accidentally excluded
  • Fixed an issue which caused the Backup Set Editor to display the wrong file size
  • Fixed an issue which caused files to be re-uploaded unnecessarily
  • Fixed an issue which caused files in Trash to be backed up

Languages

One of the two major changes in this release is support for nine languages in addition to American English:

  1. German
  2. Greek
  3. British English
  4. Castillian Spanish
  5. French
  6. Italian
  7. Dutch
  8. Portuguese
  9. Slovenian

If you have chosen one of those languages in System Preferences, Mozy will use it automatically. No assembly required. If you find spots where the translation doesn’t make sense, please let us know.

File Scanning

The other major change — the one I’m most excited about — is the new file scanning engine. This is how Mozy finds all your files and decides which ones to back up.

In the past, we’ve depended on Spotlight, Apple’s file scanning feature in OS X, for about half of our scanning. Backup Sets that searched for files of a certain type used Spotlight. Backup Sets that matched a folder (and selections made in the Files & Folders tab) scanned the hard drive directly. We kept finding that Spotlight returned inconsistent results in some cases. So we decided to stop using it.

While we were making the change, we simplified how things work and made everything but the initial scan much, much faster. Mozy now uses far less memory, even when backing up millions of files. There are still some improvements we want to make, but the new file scanning engine makes Mozy feel rock solid.

Conclusion

If you’ve gotten this far, thanks for reading. Please feel free to drop me a note (dan at mozy dot com) with any comments or suggestions. Oh, and Mozy for Mac 1.6 has two new easter eggs. :-)

If you’re new to Mozy, you can try our 2GB-for-free, no-strings-attached version here.

9
Dec

How to Optimize WordPress, Part 2

My last post on how to optimize WordPress covered some general optimization techniques to speed up a website. Reducing HTTP requests, removing wasteful plugins and decreasing file sizes helped quite a bit. Now it’s time to try out page caching.

If you remember, the five things that normally occur for each page are:

  1. Initialize PHP
  2. Query the database
  3. Create the page
  4. Send the page
  5. Send additional files

Page caching plugins, like Hyper Cache and W3 Total Cache, eliminate steps two and three, except when creating a page the first time. WP Super Cache also cuts out step one.

All of the plugins were fairly easy to install. And I discovered during my tests that WP Super Cache, at least at Nearly Free Speech.NET, works just fine with safe mode on.

This graph shows the time it took to load my home page with each of the caching plugins enabled. I have circled the point where I first turned on page caching.

Graph showing response times with various caching plugs

Hyper Cache and WP Super Cache both performed well. W3 Total Cache seemed to struggle. It does more than page caching, like reformatting files to save space, but clearly slowed things down.

WP Super Cache has a few advantages over Hyper Cache:

  1. It supports browser caching better
  2. It doesn’t need to load PHP
  3. It checks for security problems and suggests fixes

So I am now a happy WP Super Cache user.

UPDATE Dec 2009:

After a few days, I started having issues with WP Super Cache and switched back to Hyper Cache. You can see how the irregularities went away. I’ve been using Hyper Cache for almost a week now, and things have remained stable.

Graph of WP Super Cache irregularities that were solved by changing back to Hyper Cache

After being contacted by the author of the W3 Total Cache plugin, I’ve agreed to give it another try. I turned off all the settings except for “disk enhanced” page caching. I’ll update the article again in a few days.

UPDATE Jan 2010:

After looking into things a bit more, my results are still showing Hyper Cache to be faster than W3 Total Cache. However, when I test using the curl command line tool from home, it seems that both plugins are about the same speed. My web hosting company uses a network-level reverse proxy and a few other caching tricks that eliminate the need for some of the features provided by these types of plugins. I’m not sure what’s going on here, but will be sticking with Hyper Cache for now since it appears to work better with my particular situation.

I do like that W3 Total Cache handles page compression properly. I could not get page compression to work with Hyper Cache and had to turn it off. I’d recommend you try all three plugins and measure which works best for you.

UPDATE Apr 2010:

I’ve been having some troubles with Hyper Cache recently. Page redirects were working properly in Firefox, but not in Safari. I tried a new caching plugin I hadn’t heard of before: Quick Cache. Redirects are now working in both browsers. After a week of using Quick Cache, it’s performance is very good. I’ve decided to stick with it.

27
Nov

How to Optimize WordPress

Having lived with WordPress for 8 months, I decided to see if I could improve the performance of my website. There are lots of things to fix.

For each page of my website, WordPress normally does the following:

  1. Initialize PHP, which is the programming language WordPress is written in.
  2. Read information out of the database.
  3. Translate the information into HTML.
  4. Send the HTML to the web browser.
  5. Send additional files needed to view the page.

One major cause of WordPress slowness is #2. Reading all that information can take several seconds per page. I installed a plugin called DB Cache Reloaded to help figure out what was going on. If you view the source of my home page, you’ll see something like the following:

<!– 1.549 seconds, 30 uncached queries, 0 cached queries, 10.76MB memory used –>

This tells me that there are 30 database queries just to show my home page. That’s a lot of slowness. You can also see how many seconds it took to generate the page, which is how long #2 plus #3 took.

The DB Cache Reloaded plugin works by remembering the result of each database query and, in the future, using the previous result instead of re-reading it from the database. With this turned on, about 2/3rds of the database queries are avoided.

<!– 1.236 seconds, 10 uncached queries, 20 cached queries, 10.76MB memory used –>

I also discovered that the KB Robots plugin makes a database query for every page on my site. Wasteful. Since my robots.txt file is simple, I removed the plugin and just created the file myself. One less query.

To speed up #3, I explored the idea of using a plugin to cache whole HTML pages. The most popular seem to be WP Super Cache, Hyper Cache and W3 Total Cache. Since none of them work WP Super Cache does not work when PHP is running in safe mode, I’m going to try them another time. But the performance improvement should be big because, these plugins allow me to skip #2 and #3. WP Super Cache will also skip #1.

Another point of improvement is reducing the number of things a browser has to download in order to show my site (#4). Most browsers will first download the page itself. Then if additional files are needed, such as pictures, style sheets or scripts, it will download them two at a time. When there are a lot of extra files, the overhead of downloading them can add up quickly. A caching plugin will not help out here.

Though I really liked my original WordPress theme, called Panorama, it uses a lot of extra files. They aren’t very big, but when downloaded two at a time they slow things down quite a bit.

Using a web page analyizer, I investigated how much work a browser has to do to download the files needed to display my website. The following table highlights the differences between my old theme and my new one, Titan, which uses about half the number of files (10 vs 22).

Panorama     Titan
HTML11
HTML Images52
CSS Images82
Scripts53
CSS imports32
Frames00
HTTP Requests2210
Size (KB)266240
DB Queries3032


Eliminating those small files (or combining several into one) makes a measurable difference. On the day I was testing, the average time to download my page dropped from four seconds down to two.

However, notice that the number of database queries is higher now. I believe this is because of all the options the Titan theme makes available. There were originally 35 queries, but Titan includes analytics, a box in the sidebar, and a category listing in the footer. So by using the theme options instead of separate plugins for each of those things, I was able to save 3 queries. And despite the small increase in database queries, my site still feels much faster.

One last thing I tried is removing some widgets from my sidebar. I put in a new archives section, using years instead of months, that I maintain manually. I will have to update it once each year, but it reduced the size of the page slightly and eliminated a database query. Lots of small and simple improvements can really add up.

Each of my remaining sidebar sections — Popular, Recent and Random — take about a fifth of the total time to create the page (#3). Taking them out would speed things up. But I like having them to help people find other articles to read they might find interesting.

The last point to mention is the plugin I use to find related posts. I really like having these suggestions for further reading. However, most of these types of plugins are really slow because they calculate “relatedness” each time a page is loaded. Wasteful.

I’ve found one that pre-calculates related pages every time an article is created or edited, but it is based on tags rather than the full article content. And I haven’t been tagging things. I tried some auto-tagging plugins, but could not find one that seemed to work well. So until I can get around to tagging all my articles, I’ll have to wait on that.

Overall, I am pleased with the results so far. I’m going back to tag my articles so that I can try out the new related posts plugin. Then I’m going to see about turning off PHP’s safe mode and turning on page caching.

UPDATE: I’ve written a Part 2 about my experience with caching plugins. You can read it here.

2
Oct

How to Neglect a Product to Death

My friend and former co-worker Matt Ryan recently commented on the impending death of Novell Forge. A message on the Novell Forge site confirms that Novell will be shutting things down soon. I can corroborate some of Matt’s story as I was on the Forge team for about a year during its heyday.

But what really interests me about the situation are the implied instructions on how to neglect a successful product into a slow death that can be blamed on the product itself.

  1. Avoid rewarding or recognizing any of the people involved. Even better, reward someone else.
  2. Do not feed its success. Withhold funding, staffing and career growth opportunities.
  3. Provide poor support. Delay fixing problems.
  4. Set unrealistic goals and expectations. Blame the product or team for failure.
  5. Find excuses to kill the project. Focus on the negative in all meetings with executives.

This was a particular worry at Mozy when it was acquired by EMC. They promised that EMC did not want to be the lumbering elephant that accidentally squashed its shiny new purchase. And it was true. But we worried about accidental squashing anyway.

It has been two years, and I have seen projects and executives come and go. Though I do not believe it was intentional, at times it felt like Mozy was being neglected. But the core of Mozy has remained strong and continues to grow.

Based on my experience, here is what to do to keep a successful product moving forward:

  1. Execute anyway. Deliver a quality product in the face of neglect.

There is precious little a neglected production team can do other than produce. I heard something once I have always remembered: nothing succeeds like success. It is much harder to produce in the face of neglect, but it is also nearly impossible to ignore or argue with.

Mozy is clearly not perfect, but despite occasional neglect it continues to provides a valuable, profitable service. Working with smart people helps. Working for smart people helps. Working with people you like helps. Working on something you care about helps. Working with cool technology helps. But over time, delivering a useful, profitable product is what matters.

30
Sep

Changes in Mozy for Mac 1.5

After a two week beta period, the 1.5 release of Mozy for Mac was released today. We’ve made a lot of improvements over the last few releases. If you’re new to Mozy, you should try our 2GB-for-free, no-strings-attached version here.

The official announcement is on our blog. Here’s more details about what changed in this release:

Enhancements

  • Consumer and business versions of the software can now run simultaneously on the same machine.
  • Added a file scanning progress indicator in the Configuration window.
  • Added a warning that appears when a backup is started before the product is fully configured.
  • Added a warning to prevent changes being lost when the Configuration is closed without saving.
  • Simplified the list of options in the menu bar.

Bug Fixes

  • Improved memory usage during backup and restore.
  • Improved the way network encryption keys are retrieved.
  • Improved the ability to restore default backup sets in the Configuration window.
  • Improved the efficiency of the log file collector.
  • Improved the handling of temporary files.
  • Improved the handling of database corruption.
  • Eliminated unnecessary API calls to improve performance.
  • Fixed an issue that prevented some Mac 10.4 (Tiger) users from backing up properly.
  • Fixed many instances of potential configuration corruption.
  • Fixed an issue importing a personal key into the decryption utility.
  • Fixed a potential root exploit security issue.
  • Fixed an issue that prevented some files with aliases in their paths from being backed up.
  • Fixed an issue where Status would get stuck if the backup process was not running.
  • Fixed an issue that caused Restore to crash for some users.
  • Fixed a rare issue when restoring files with resource forks.
  • Fixed an issue where the uninstaller missed some files.
  • Fixed an issue with handling email addresses containing a “+” sign.
  • Fixed a display defect in the Files and Folders tab.
  • Fixed a display defect with the “Temporary Files Location” in the Preferences window.
  • Fixed the display of exclusion notifications.
  • Fixed a display defect which appeared after saving changes in the Configuration window.
  • Fixed a rare issue which forced user credentials to be reentered.
27
Aug

How to Create an Alias Programmatically

First, a disclaimer. Apple will warn you not to do this. The only supported way of creating an alias is to use the Finder. If you must do it programmatically, you will be told to use AppleScript. But if AppleScript won’t work for you, and a simple Cocoa method is what you want, read on.

Mozy’s Mac client doesn’t create aliases, but our customers do. We want to make sure our software backs them up correctly. So we added some unit tests to our build process that create aliases and check to see that Mozy handles them correctly.

We first used AppleScript, but ran quickly into two issues:

  1. Our build server runs as the root user, which doesn’t have a UI context. AppleScript doesn’t work without a UI context.

  2. Even running as a normal user, AppleScript cannot access the system temporary files location (/tmp) which is where we wanted to create our aliases.

That’s when the fun began.

I spent quite a bit of time failing to find the right bit of magic to create an alias that functioned properly in Finder. It turns out that an alias is a data structure inside another data structure stored in the resource fork of an empty file. Those structures need to have the correct record types for everything to work.

Having gone to the trouble of figuring this out, I thought I’d share. This code creates an alias for a folder, but it should serve as a good template if you need to create another type.

- (void)makeAliasToFolder:(NSString *)destFolder inFolder:(NSString *)parentFolder withName:(NSString *)name
{
    // Create a resource file for the alias.
    FSRef parentRef;
    CFURLGetFSRef((CFURLRef)[NSURL fileURLWithPath:parentFolder], &parentRef);
    HFSUniStr255 aliasName;
    FSGetHFSUniStrFromString((CFStringRef)name, &aliasName);
    FSRef aliasRef;
    FSCreateResFile(&parentRef, aliasName.length, aliasName.unicode, 0, NULL, &aliasRef, NULL);

    // Construct alias data to write to resource fork.
    FSRef targetRef;
    CFURLGetFSRef((CFURLRef)[NSURL fileURLWithPath:destFolder], &targetRef);
    AliasHandle aliasHandle = NULL;
    FSNewAlias(NULL, &targetRef, &aliasHandle);

    // Add the alias data to the resource fork and close it.
    ResFileRefNum fileReference = FSOpenResFile(&aliasRef, fsRdWrPerm);
    UseResFile(fileReference);
    AddResource((Handle)aliasHandle, 'alis', 0, NULL);
    CloseResFile(fileReference);

    // Update finder info.
    FSCatalogInfo catalogInfo;
    FSGetCatalogInfo(&aliasRef, kFSCatInfoFinderInfo, &catalogInfo, NULL, NULL, NULL);
    FileInfo *theFileInfo = (FileInfo*)(&catalogInfo.finderInfo);
    theFileInfo->finderFlags |= kIsAlias; // Set the alias bit.
    theFileInfo->finderFlags &= ~kHasBeenInited; // Clear the inited bit to tell Finder to recheck the file.
    theFileInfo->fileType = kContainerFolderAliasType;
    FSSetCatalogInfo(&aliasRef, kFSCatInfoFinderInfo, &catalogInfo);
}

I consider this code to be in the public domain. Please feel free to copy and paste. And let me know if you find any problems or have suggestions.

If you need a complete solution, Nathan Day wrote a nice set of classes called NDAlias. We didn’t want to import 9 classes for just a handful of unit tests.

I later found some of Apple’s sample code from 1999 demonstrating a similar approach. I think our Objective-C example is much easier to use.

25
Aug

WordPress After 8 Months

Early this year, I switched from Movable Type to WordPress for my blog. I’ve been very happy with that decision. So I thought I’d give an update on how I feel after using WordPress for eight months.

First, I should say that the speed issue hasn’t bothered me like I thought it would. I haven’t added caching, but may still do so at some point. Let me know if things feel slow.

Second, I’ve changed the which plugins I use, so let me give you the current list.

  1. NEW — Twitter Friendly Links let’s me use my own domain for short URLs instead of Bit.ly or TinyURL.com
  2. NEW — RF Twitter Post will update Twitter when I write a new post. I’m testing this one and hoping the next version adds support for Twitter Friendly Links
  3. NEW — SexyBookmarks makes it easy for readers to share things they find interesting
  4. Aksimet filters comments from spammers of which there are many
  5. All in One Adsense and YPN handles the ads on my site though I have them turned off now
  6. FD Feedburner Plugin lets me use FeedBurner for my RSS feeds
  7. Google Analyticator adds the Google Analytics tracking code
  8. KB Robots.txt allows me to add my sitemap to my robots.txt file
  9. Markdown allows me to write using Markdown syntax
  10. Recently Popular highlights what posts people find interesting
  11. Simple Google Sitemap automatically creates a sitemap for me
  12. Twitter lets you know exactly what I’m up to at all times
  13. WP-DB-Backup makes it easy to back up the content on my site
  14. Yet Another Related Posts Plugin suggests additional posts that relate to the one you’re reading

Since January, I’ve stopped using Automatic Timezone because putting WordPress 2.8 and PHP 5 together makes the daylight savings time magic work.

Third, I was able to find several WordPress themes that I liked and get them installed fairly easily. And switching between them is simple.

Overall, I’m still very happy.

2009-12-05: I spent some time optimizing WordPress which you can read about here.

3
Aug

Changes in Mozy for Mac 1.4

The Home and Pro versions of Mozy for Mac 1.4 are out. We’ve been working on this since January, and it feels great to finally get it out the door.

The major change in this release is the new file scanner. We’ve greatly improved how Mozy looks for and keeps track of files that need to be backed up. The release has been enabled this afternoon for new customers and existing customers which manually upgrade using the links above. Auto-update will be turned on for all existing Home and Pro customers shortly.

Since we don’t have an official place for showing our Home users a list of what’s changed, I’m including the full list here.

Enhancements

  • Improved overall performance and stability for file selections and backups
  • Added menu option to automate the collection of log files
  • Moved Preferences to global System Preferences
  • Improved sorting of the Files and Folders Configuration window
  • Improved the behavior of saving and canceling in the Configuration window
  • Added a new icon to indicate partially backed-up folders in the Configuration window
  • Added menu item to start a backup from the Configuration window
  • Added the ability to create backup sets to exclude files
  • Added the ability to sort by column in the Backup Sets window
  • Updated online guides
  • Added menu item to send product feedback or suggestions
  • Improved appearance of menu bar icons and other graphics
  • Improved speed of file preparation
  • Added the ability to use the escape (ESC) key to close the Configuration window

Bug Fixes

  • Fixed rare case of file changes not included in backup
  • Fixed several “database is locked” and “database disk image is malformed” errors
  • Fixed memory leaks
  • Increased the accuracy of the bandwidth throttle
  • Fixed creation date issue for restored files
  • Fixed problem with excluded folders being backed up
  • Fixed an issue limiting the amount of custom backup sets
  • Fixed an issue when the user restarts the computer before completing installation
  • Removed redundant column in the Backup Sets window
  • Fixed an issue restoring a file with a resource fork
  • Fixed an issue restoring a file with identical copies being backed up
  • Fixed the occasional “ClientError15″ error caused by stopping a backup in progress
  • Fixed “no files selected for backup” message from mistakenly being displayed in the Configuration window
  • Fixed some Snow Leopard compatibility issues

UPDATE: We’ve got an official announcement on Mozy’s blog. I updated the links to point to the 1.4.3 release, which has fixes for OS X 10.4 and Time Capsule.

2
Jul

Mozy Coupon for July

Mozy is offering 10% off new annual and bi-annual subscriptions for MozyHome Unlimited and MozyPro this month. Just type JULY into the referral box when you sign up.

If you’re interested in Mozy’s free 2GB of online backup, just sign up for a MozyHome Free account. I’d recommend using someone’s referral code as you’ll both get an extra 256MB of space. If you can’t find a referral code online, you can use mine which is 56EEVL. But Mozy employees get free accounts so try to hook someone else up if possible.

And if you’re a Mac user interested in helping us beta test the Mozy for Mac 1.4 release, please drop me a line at dan at mozy dot com.

20
Jun

Review: AppleTV

I’ve been using an TV (also known as AppleTV for those who lack Shift-Option-K goodness) for about a year now. It’s a great little device with a couple of really annoying flaws.

The Good

I like that It’s small, about an inch tall and eight inches on each side. It has an HDMI video output, and both optical and analog sound outputs. It can play almost anything in my iTunes library.

The best thing is probably the screensaver where pictures from your iPhoto library float up the screen. We hardly ever look through our “digital albums” on the computer, and it’s nice to have an easy way to see all those pictures.

The Bad

In order to play properly on the TV, movies have to be below a certain quality. iTunes will play high-quality movies that the TV ignores. The TV handles most mainstream movie formats, including H.264. But it is not upgradable unless you’re willing to tinker a bit. I’d like to see support for Netflix, Hulu and others built-in.

The parental controls option prevents purchases, but does not hide anything nor prevent previews. I assume the only reason to include that feature is for kids, so why not just hide filtered content completely? If I want to watch something else, I’d be happy to put in my passcode to see the filtered content. Since the filtered content is not hidden, the whole feature seems nearly useless for me.

The Ugly

The TV never sleeps. Which means it always seems hot enough to roast an egg. I would really like an option to “sleep after so many minutes.” Or at least have it turn off the hard drive. It’s hard on the drive and wastes energy. Unlike the TV, I do sleep at night.

The worst thing is how slow the navigation feels on occasion. Even with the most recent software update, there is way too much stuttering and jumping. I suspect this occurs because I am streaming content from my iTunes library on another computer.

I could avoid streaming if the hard drive in the device was bigger. Or if it was semi-easy to put in a new one. Or if it supported external drives connected via the USB port. It doesn’t happen all the time, but waiting even 3 seconds for it to respond is really annoying.

Conclusion

Overall, I like my TV. It’s really easy to setup, and gives me a simple way to watch or listen to media stored on my computer. A Mac mini would work too, but is more expensive. It also lacks an HDMI output. And I worry that my kids would be confused if it ever dropped out of Front Row, the TV-like software that comes with Macs.

On the other hand, a mini is a computer which makes it easy to customize. It would allow me to watch streamed movies and rented DVDs (the TV lacks a DVD player). I wonder why Apple doesn’t allow the TV to play DVDs that are in another computer sort of like they do with the Macbook Air.

If I had my purchase to do over again, I’d certainly get an TV or a mini. Just not sure which one. What I’d like is a mini with an HDMI port.

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