Mr. Fixit

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There are 111 posts filed in Mr. Fixit (this is page 2 of 12).

I feel the need … the need for speed

Optimizing MarkTurner.Net

A few days ago I was playing with Pingdom’s Website speed test and shocked to find how long it was taking MT.Net to load for my legions of website visitors. There were several things slowing it down, earning my site a grade of a gentleman’s “C.”

After digging through some of Pingdom’s suggestions and carefully pruning my WordPress plugins and settings, I’ve managed to whittle down the load time from an average of over 3 seconds to just a hair over one second.

While there’s probably a little bit more performance I could squeeze out this is far better than it was. Enjoy!

‘Kernel memory leaking’ Intel processor design flaw forces Linux, Windows redesign • The Register

A massive security issue has been found in Intel’s processors that will very shortly have a huge performance impact on almost all computers. Details are sketchy at the moment but it’s not looking good.

Remember the Year 2000 (Y2K) bug? This is likely to eclipse Y2K. Why? Because patching broken software is trivial but patching broken hardware is all but impossible. We will feel the effects of this design flaw for years. Soon nearly all computers you interact with (including online services like Facebook, SalesForce, Netflix, etc) could be from five to thirty percent slower.

When I purchased a new Intel processor last year, I did so thinking it would give me a decade or more of service. Now it’s already obsolete. If any class-action lawsuits spring up over this I would be willing to join in. This is ridiculous.

A fundamental design flaw in Intel’s processor chips has forced a significant redesign of the Linux and Windows kernels to defang the chip-level security bug.

Programmers are scrambling to overhaul the open-source Linux kernel’s virtual memory system. Meanwhile, Microsoft is expected to publicly introduce the necessary changes to its Windows operating system in an upcoming Patch Tuesday: these changes were seeded to beta testers running fast-ring Windows Insider builds in November and December.

Crucially, these updates to both Linux and Windows will incur a performance hit on Intel products. The effects are still being benchmarked, however we’re looking at a ballpark figure of five to 30 per cent slow down, depending on the task and the processor model. More recent Intel chips have features – specifically, PCID – to reduce the performance hit.

Similar operating systems, such as Apple’s 64-bit macOS, will also need to be updated – the flaw is in the Intel x86 hardware, and it appears a microcode update can’t address it. It has to be fixed in software at the OS level, or buy a new processor without the design blunder.

Source: ‘Kernel memory leaking’ Intel processor design flaw forces Linux, Windows redesign • The Register

Bonus link: Some technical speculation on the bug from “pythonsweetness.”

Broken DHCP on the Ubiquiti EdgeRouter Lite

The Ubiquiti EdgeRouter Lite (ERL), an amazing little networking box.

Back in October I finally squeezed gigabit speeds out of my AT&T Fiber connection by switching from my old OpenWRT-based TP-Link Archer C7 routers to an Ubiquiti EdgeRouter Lite (ERL). The Archer hardware could not keep up with gigabit speeds but the ERL can.

I love the ERL! It’s only about $100 but it’s a very powerful device! Previous versions of the firmware were a bit cryptic (at least in the UI area) but the latest one provides a lot of functionality (and wizards).

I had followed one such wizard to do my initial setup with the ERL back in October, after upgrading it from version 1.9.1 of EdgeOS to EdgeOSv1.9.7+hotfix.4. All seemed to work … except for it properly pulling a DHCP address from AT&T. See, I have bypassed AT&T’s PACE router in favor of my own and the ERL now does everything but the initial 802.1x authentication that opens the port on AT&T’s switch.

Why do you need to use DHCP on your AT&T link? You can put a static IP on your end of the link but AT&T offers DHCP leases of 14 days and expects you to use them. If your box (i.e., my ERL) doesn’t renew its IP near the end of those 14 days, AT&T considers the link to be dead and shuts down the connection. At this point, the only way you’ll get it going again is to reconnect the AT&T router and let it do its 802.1x authentication again. This is a pain, so avoiding it is very useful.
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Fence is structurally complete!

My fence: it’s critter-proof now!

I nailed on the last few pickets to our new fence yesterday. These took some time because they had to be custom-sawed to fit the odd gaps left when the full pickets didn’t line up. Rather than stop and cut individual boards during my previous fence work days, I chose instead to keep motoring so I got more surface area done. Thus, there were about ten or so odd-shaped pickets to create.

A few hours of measuring, cutting, and nailing on Sunday and I had the fence structurally complete. It is now critter-proof. I put in the last board as the sun was going down and then took out a section of our old fence so that we could enjoy our entire backyard for the first time ever. Hurray!

Now I need to go back and trim down the too-tall posts and 2x4s. I may even cap the posts to better weatherproof them. Then I will take down the old fence and either haul it to the dump or find neighbors who might want to scavenge it for spare pickets. I’ll also have to fill in the holes left by the old fence posts. Still a bit of work to be done but I’m getting there!

Fence work progressing

It’s looking more like a fence

One of the things we’ve been meaning to get done is to move our backyard fence to the outer limits of our property lines. For some reason when the fence was first built, the fence was put 8-20 feet inside of our property, leaving the rest our of property essentially abandoned. Miss Ruth had adopted our property on her side of our fence and we never had the heart to “take it back” while she lived here, so when we got new neighbors it seemed time to make the change.

Only I’d never built a fence before.

Enter YouTube. You can learn anything on YouTube.
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Streaming live video from the 3DR Solo

I have had a 3DR Solo drone since last summer and have been looking for interesting ways to expand its capabilities. One thing that I thought should be possible is to stream live video from the drone while it’s in flight. The Solo controller has an HDMI port to push video to a monitor but I wanted to see if I could get to the video stream directly, through software. I’m proud to say that I figured out how to do it.

First you need a separate computer, preferably a laptop or something portable. The computer will need to connect to the WiFi network that the Solo controller creates. Once you’ve got your computer joined, make sure it’s connected by pinging the controller (IP address 10.1.1.1).

Next, create an SDP file on your laptop as discussed on the 3DR Solo wiki.

c=IN IP4 10.1.1.1
m=video 5600 RTP/AVP 96
a=rtpmap:96 H264/90000
t=0 0

… save this as sololink.sdp.

The controller will only stream video if it’s got a TCP connection from the host requesting a stream. In a terminal window, connect to the controller as follows:

telnet 10.1.1.1 5502

or

nc 10.1.1.1 5502

Now the controller should be able to stream video using a tool such as VLC or ffmpeg. For VLC, open the osololink.sdp file you created above. You should see the drone video appear on your laptop. VLC is nice for checking the video but I haven’t worked out how to send it to YouTube yet. I believe it does not properly handle the RTMP media format that YouTube needs, though I’m not sure of this.
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Intel NUC as home server

It's nice when your server fits in your mailbox.

It’s nice when your server fits in your mailbox.


I’ve always liked to have a home server hanging around for things like email, file sharing, and the like. Over the years this has taken the form of a beefy desktop computer, a PowerPC-based MacMini, an embedded Linux-based router, and recently a beat-up old laptop. All had their challenges, power consumption and fan noise being the two main ones, though the PowerPC machine and the router also couldn’t run all the software I needed. I was limping along on my busted laptop for as long as I could but decided it was nearing the end of its useful life. It was time to go shopping for something that would last me a while.

The embedded idea still appealed to me for the two main reasons I mentioned above: power consumption and noise. I wanted something that sips electricity and was quiet yet still provided enough computing power to do what I needed. After reading up on some online reviews, I went with the Intel NUC.

Intel’s NUC (“Next Unit of Computing”) systems are embedded x86_64 machines which are about half the size of a brick. They have plenty of ports: HDMI, USB 3.0, and even a Thunderbolt port. They come with your choice of Intel processors, whether it is an i3, i5, or i7 series. Memory can be boosted to 32 GB and it accepts newer SSD drives. Some models can fit 2.5″ laptop drives as well. The hardest part about making the jump to an Intel NUC was simply deciphering which Intel model had which options. Sometimes having too many choices isn’t a good thing, I suppose.
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Speeding point proven at 2 AM

I’d spent many evenings last week going door to door along State Street, methodically collecting signatures on a city petition to reduce the State Street speed limit to 25 MPH from its current 35 MPH. The first two days garnered the lion’s share of signatures; before I knew it I was up to ten. The last four, however, have been a challenge. Some neighbors tell me they agree 100% with reducing the speed and yet they’re very reluctant to put their name on the list. Some of these neighbors are older and some are renters who are perhaps worried any more neighborhood improvements might price them right out of the home they are renting. It’s hard to know what their real reasons are but it’s frustrating that they want it done and yet don’t want to do anything to make it happen.

Sunday afternoon I was particularly bummed when some friends I thought I could count on to sign decided against it, citing the mess that the water main replacement/traffic calming on Glascock has been. Even though I stressed it was only a new set of speed limit signs I could not convince them. I felt like chucking my clipboard into the street and giving up on the whole damn process. It would be just like five years ago, when I spent hours walking up and down State only to collect just enough signatures to barely miss the threshold.
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Boost of civic energy

No sooner had I written my previous post that I got a boost of civic energy, this one from attending Monday night’s East CAC meeting. It had been a long while since I had been to a meeting, with my involvement in the Ligon PTA taking up much of my free time as well as other things like Friends of Dorothea Dix Park.

Monday’s meeting featured information on the purchase of Gateway Plaza, right outside of my neighborhood, so it provided a compelling reason to be there. There wasn’t much information provided but seeing many of my friends and neighbors there after such a long time was really fun. The same boost of energy I always got when conducting East CAC meetings was still there. My neighborhood inspires me! It’s good to know I can always come back.
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Tracking planes with dump1090

A RTLSDR receiver and dump1090 can track planes hundreds of miles away.

A RTLSDR receiver and dump1090 can track planes hundreds of miles away.

As an amateur radio operator and full-time geek, I’ve always been interested in the convergence of technologies, especially when the convergence scratches a few of my itches. One one of my latest hobbies is tracking commercial airliners through their ADS-B broadcasts. It’s a hobby that doesn’t take much time outside of setting it up. In about two hours, I configured a receiver, built an antenna, and set up software that shares what I find with the world, and all for under $30. Here’s how I did it.

The ADS-B protocol is a digital “status update” signal broadcast by airplanes which updates other aircraft around it with important location information and the like. The FAA would eventually like to see ADS-B take the place of ground-based radar but not all airplanes use it yet. Transceivers are still pricey and owners of general aviation aircraft like Cessnas largely haven’t yet adopted the system. There’s an amazing amount of data being sent and anyone with the proper receiver can intercept it (oops, that’s what we called radio reception when I was a Navy cryptologic technician), and that receiver can be dirt-cheap like the RTLSDRs.

Three years ago the radio-geek world was set ablaze when it was discovered that a mass-market DVB-T USB device had the ability to become a software-defined radio, basically a wide-range receiver that can easily decode almost any signal. Hobbyists soon were using these $15 RTLSDR dongles for just about everything, including tracking airplanes. I had a few lying around that weren’t really being used for anything so I hooked one up to my Raspberry Pi
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