Archive for April, 2012

Arq plugin for Sidekick

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April 28th, 2012

Arq Forum member jmah did some reverse-engineering of Arq and posted a message about a plugin he wrote for Sidekick which tells Arq to back up whenever he returns home.

The source code is on github.

Really clever! I love it.

Arq 2.6.9 is out

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April 28th, 2012

Arq version 2.6.9 is now available!

This minor update fixes several minor issues, including the issue where some backup sets weren’t appearing under “Other Backup Sets”.

It’s a free update for all Arq users. Pick “Check for Updates” from the Arq menu to get the update.

As always, full release notes for all Arq versions are on the release notes page.

Arq 2.6.8 is out

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April 3rd, 2012

Arq 2.6.8 is available. To update, pick “Check for Updates” from Arq’s menu.

Please note: Arq 2.6.8 may upload much more than you expect or want it to the first time it backs up. This is due to a bug that I unfortunately created in version 2.6.3. I apologize for this. Please let it finish backing up.

There is no charge from Amazon for data transfer to Amazon, but I realize that re-uploading a lot of data is a long, frustrating experience.

The full story of what happened starting with Arq 2.6.3

There’s a problem with some of S3′s servers, particularly in the us-west-1 region, but also in other regions. Connections just get “stuck”. Customers were complaining heavily about Arq getting “stuck”. I was initially unable to reproduce the problem, but felt I had to do something to fix it. The Apple networking API that Arq was using had no facility for timing out; plus it was very hard to throttle properly. So I changed Arq to use Apple’s older CFHTTP API. 

In my haste to fix this customer problem, I didn’t do enough testing on 2.6.3-4. I screwed up. There was a bug in those releases where some objects were marked as “compressed” but they weren’t actually compressed. So Arq couldn’t restore properly.

What really made things bad was that at some point in my rush to get the issue fixed I accidentally (because of muscle-memory habit) ran the command to publish 2.6.3 in the “update stream” as an official release of Arq, which meant that everyone who happened to check for updates would get this buggy version. I didn’t realize this for several hours. At that point I could only move forward and fix things as quickly as possible.

Since there’s no way for me to tell which objects were compressed, Arq 2.6.5 (and later) ignores all backups made after March 7 by an Arq version older than 2.6.5. I added a “version” to the backup data so that if this sort of thing ever happens again, I can fix it with a less drastic solution.

I’ve also added some “gates” to my release process so that I don’t inadvertently do this again.

Arq 2.6.6 through 2.6.8 contain very small changes — checks for various network errors that were causing Arq to fail the backup instead of retry.

Please let Arq finish doing what it’s doing. It will clean up all the “bogus” S3 data after it successfully backs up everything.

Also, please consider using more than one backup system, as I blogged about in 7 facets of a good Mac backup strategy.