December 2009 – Page 2 – Mostly Harmless

December 6, 2009

That’s all I can take!

After my complaining and moaning for months my Dell XPS 720 refuses to boot up this morning. Again. That’s the final straw and I ordered a new PC this morning.

I was planning on building my own PC but the fact is I don’t have time to do that. Building a PC from parts is not really fun for me anymore and I just want the flipping thing to work.

I have been purchasing Dell equipment for years and recommend them to people all the time. But lately the Dell experience has soured. Even my buying a budget Ubuntu based Mini from Dell turned into a horror show.

In my basement I have a HP/Compaq Presario 8000. It’s 8 years old and has never given me any problems. That’s the sort of experience I’m hoping for with this new model so HP gets the nod from me today.

So with a budget in hand I purchased the following PC online from HP.

HP Pavilion Elite e9280t PC

    • Genuine Windows 7 Home Premium 64-bit
    • Intel(R) Core(TM) i7-920 processor [2.66GHz, 1MB L2 + 8MB shared L3 cache]
    • 12GB DDR3-1066MHz SDRAM [6 DIMMs]
    • 1.5TB 7200 rpm SATA 3Gb/s hard drive
    • 1.8GB NVIDIA Geforce GTX 260 [2 DVI, HDMI and VGA adapters]
    • LightScribe 16X max. DVD+/-R/RW SuperMulti drive
    • Integrated 10/100/1000 (Gigabit) Ethernet, No wireless LAN
    • 15-in-1 memory card reader, 1 USB, 1394, audio
    • No TV Tuner
    • Integrated 7.1 channel sound with front audio ports
    • No speakers
    • HP multimedia keyboard and HP optical mouse
    • Microsoft(R) Works 9.0
    • Norton Internet Security(TM) 2010 - 15 month
    • HP Home & Home Office Store in-box envelope

Estimated build date: December 16, 2009

I came in $43 over budget. Lily will forgive me.

I’ll remove most of the HP consumer software and put on my own. This will be a drop in replacement for the 81lb behemoth next to my desk. It’s not a top of the line PC gaming rig but it is a good upgrade from my existing PC. Hopefully I will get it before Christmas.

I can’t wait for my XPS 720 to come out of it’s drunken stupor and give it the news of it’s replacement.

December 5, 2009

Beware the canary mismatch on efree monster

For traffic logs, I use Clicky Web Analytics and take a look from time to time. See that flat dark blue line? Around noon on December 3rd my blog stopped serving web pages and it was not until about 5 hours later that I noticed it. I don’t get a lot of traffic but I do like my blog to be working.

It wasn’t that my VPS went nuts, the CPU usage was fine. What was happening was that my PHP interpreter was tossing hundreds of these errors.

[Thu Dec 03 12:17:27 2009] [error] [client 66.249.71.233] ALERT - canary mismatch on efree() - heap overflow detected

Not cool and until I restarted Apache2, my blog was not serving anything. PHP just kept blowing up. This has been an ongoing problem for me that has been attributed to the Suhosin PHP security patch and I had not found the magic bullet to fix.

I’m not going to disable the hardened PHP. That’s like turning off the safety switch on an excercise treadmill. It’s juts not safe.

As a work around I have done the following: I activated the WP Super Cache plugin, removed the Xcache op cache I setup, and disabled the ssh2 PHP extension I installed.

The WP Super Cache created static HTML pages for your dynamic content. It does cache expiration, garbage collection, etc. and limits the amount of time PHP needs to be run.

The XCache was a hold over from when I was running my blog on a Pentium II. The VPS I use is very responsive and losing it does not hurt me. Using the Pingdom tools I can see that I still get a good response from my web server.

Losing the ssh2 was easy; I only added it to my PHP to be able to answer a WordPress support forum questions. I never use it. I’ll look for any other PHP extensions that I added as a “what the hell” but so far so good. No more canary mismatch errors as yet.

December 5, 2009

Now trying OpenDNS SmartCache

If you are an IT/Network professional with UNIX/Linux/BSD experience and you have a network at home, you really can’t resist playing around. It’s the best way to learn and causing outages at home will only irritate your family.

I’ve been using Google Public DNS for a day or two and it’s fast and responsive. Even though a simple test shows that Google’s Public DNS on a per query basis is slower, the end user experience has been faster (at least for me). But OpenDNS is more feature rich and I’d like to see if I can get a good experience using it.

I revisited my OpenDNS account dashboard and found out that they now offer an option called SmartCache, which I have enabled. I also downloaded the OpenDNS Updater onto my kitchen notebook. That notebook is on all the time and it make’s sense to run it there. FIOS has already once given me a new IP address and I want my OpenDNS settings to follow my network at home.

OpenDNS’s blog has a good explanation for SmartCache here and more info here. It’s a useful feature and you have to applaud them for offering it to their free account users.

End user experience is a very subjective thing so I’ll see if OpenDNS has the same feel or better as Google Public DNS. Like most folks, I just want web browsing to work and be fast.

December 3, 2009

Google Public DNS or OpenDNS?

Disclaimer: one of my brothers works for Google, I like Google and I hope they are wildly successful.

Google announced that they are offering a fast, highly available, and secure public DNS. It’s not a TLD registrar like Verisign but it’s supposed to be fast. I’ve been using it for a couple of hours and the name resolution is zippy.

It’s not OpenDNS and I don’t think it’s intended to be. OpenDNS has about the same things only it also provides you with an account and a dashboard where you can set options such as filtering. OpenDNS is a developed service and it’s well thought out and implemented. You can read on their blog some thoughts from OpenDNS on this new development.

That all said, I think mixing the words “Google” and “DNS” will be bad for OpenDNS. They probably have competition but I can’t think of one. The OpenDNS is free and many people use it. Google’s public DNS is only a resolver and has no features. Now it looks like Google has entered that area and I think it will be successful and more people will move over to it.

I took 100 unique DNS names from my web proxy log (squid proxy, don’t you run one at home too?) and ran a simple command

dig hostname @8.8.8.8

The output contains a line like this

;; Query time: 21 msec

I ran those 100 dig commands and added up all the query time milliseconds and came up with 7550 milliseconds or 7.5 seconds for using Google.

The OpenDNS server IP address 208.67.222.222 with the same exact queries and took 1347 milliseconds while FIOS’s 192.168.1.1 (my cable mode that forwards to the real DNS IPs) ran for a total of 1668 milliseconds.

That’s not really a comprehensive test but it looks like OpenDNS is faster for now and it is very feature rich. But this should be interesting to see how this plays out since Google aims to have their solutions work best.

Month: December 2009 (page 2 of 2)

That’s all I can take!

Beware the canary mismatch on efree monster

Now trying OpenDNS SmartCache

Google Public DNS or OpenDNS?

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Jan Dembowski

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