Click date twice, then click the eyeballs icon (‘click to sort by read’) twice.
Posting this here because I forgot and it was really annoying.
Tips - 6. page
Using Munin To Track Business Values
Munin is a great piece of software that we use at my company to track overall trends in disk usage, CPU and other system purposes. Now, we don’t have a ton of servers, so I’m not sure how munin scales for many machines, but it has been invaluable in troubleshooting problems and giving us historic context.
One thing we’ve started to do is to incorporate business specific metrics into munin. This is good because it ties the technical operations more tightly to the business, making us aware when there are issues.
Anything you can run a sql query or do a wget for, you can graph in munin. (Here’s something I wrote about writing munin plugins a year ago.)
I don’t think that munin is acceptable as a general purpose dashboard. I’d probably look at Google Analytics if I was web drivingdriven (updated Feb 25 2012), and at statsmix if I needed to integrate a bunch of disparate services. But for bringing additional business awareness to a technical team, writing a few custom munin plugins that will graph key business metrics can be very useful.
How to connect a Jabra VBT2050 earpiece to a Palm Centro
Everyone should use an earpiece. My SO is reading “Disconnect: the truth about cell phone radiation, what the industry has done to hide it, and how to protect your family” and it’s some scary stuff.
I’ve struggled with setting up my earpiece enough times that I want to document what I did just now. There are a lot of instructions on the internet, but they all seem incomplete, or aimed at a different phone. Here’s the Jabra manual (PDF), even though it isn’t much help.
So, here are my step by step instructions on how to connect my AT&T Palm Centro with my Jabra VBT2050 earpiece.
- Turn off the earpiece by holding down the side button until you see 4 fast blinks. Disconnect it from the charger.
- Then, turn off bluetooth on the phone. Disconnect it from the charger.
- Turn on the bluetooth on your phone
- Make sure your phone’s bluetooth setting is ‘visible’
- On the phone, choose ‘setup devices’
- Choose ‘trusted devices’
- Choose ‘add device’
- Turn on the Jabra earpiece by holding down the button you used to turn it off
- Continue to hold the on/off button down until you see it blinking three times slowly.
- Press the center button of the earpiece (the one you use to connect/disconnect calls) for about 10-20 seconds, until the light on the earpiece is steady.
- Choose ‘find more’ on your phone.
- Select the Jabra earpiece.
- Choose ‘OK’
- Enter the passcode: 0000 (I’ve not found a way to change this, which seems rather idiotic).
- Choose ‘OK’ You should now be at the ‘Trusted devices’ screen.
- Select the Jabra earpiece from the list
- Press the menu key on your Centro. It’s next to the ‘Alt’ key.
- Select ‘Connect’. The earpiece should be blinking one time slowly.
- Click ‘OK’ on out. You should see a blue set of headphones next to your bars when you get to the main screen.
- You can change your phone’s bluetooth visibility to ‘hidden’
Hope this helps!
Gratitude List
Every so often, I just need to stop and say thanks.
Thanks for my family and parents, providing all kinds of education when they raised me.
Thanks to my wife, for being patient and loving, even when I’m not my best.
Thanks to my past and current clients, colleagues and employers, for giving me amazing opportunities, challenging me and trusting me.
Thanks to the vast number of people who contribute to making the internet a fantastic place (this is a software blog, after all). Whether you create content or build plumbing, the internet is richer for your contribution (even the guy behind lolcats, but especially stuff like this and this).
Every so often, I get wrapped up in some small drama, but nothing knocks me back on my heels and makes me say ‘Damn, I’m lucky’ like making a gratitude list, even one like this which is incomplete.
Say thanks–it feels good!
Shuttering a blog
Not this one! But recently, as part of an effort to simplify my life, I’ve shuttered a couple of blogs I had been running for a while. Here’s my list of best practices to do so:
- Forgive yourself. Running a blog is a lot of work, so if you don’t have time to do it adequately, it’s better to admit it than to do a poor job.
- Try to find someone else who is interested. If you’ve built up a following (you know how many visits you’re getting a day, right) and want to continue to see whatever topic you are blogging about more fully explored, you may be able to find someone else. If you do, make sure to add them as a contributor, and discuss where they see things going from there–do they want to fully take over the blog, just write the occasional post, or what?
- Announce the hibernation on the blog. Feel free to phrase is as a long pause, or a hibernation, or whatever, but make sure you tell your readers.
- Leave the content up for as long as you can. Consider moving it to a different server if you need to consolidate, but if you’ve put up useful posts, people will continue to visit via search engines.
- Leave up your contact info as well. I’ve had several emails about my shuttered blog, and they’ve actually spiked my interest to start writing again.
- Shut down your CTAs; for instance, I had a newsletter signup on one blog. To me, it’s not fair to ask people to give their email address if I’m never going to send them useful content. Along with the previous two suggestions, this is really about being respectful of your readers.
Do you have any tips for shutting down a blog in a graceful manner? Here’s an interesting post on the topic, but written from the perspective of a more professional blogger.
How to get IE to accept third party cookies
Third party cookies are most often used by ad serving companies, because they are set by an image or other resource that can be pulled from a different domain, they are one way of tracking behavior across websites.
A short example: If I visit site A (www.foo.com) and site B (www.bar.com) and they both pull an image from site C (www.baz.com), it can set cookies for the site C domain (.baz.com), with a value of siteA or siteB. Then when I visit site C, it ‘knows’ that I’ve been to sites A and B.
This can be sinister (see the wikipedia link above for privacy concerns). However, if you have multiple web properties, then you may want to tie user behavior together across properties. Third party tools like Google Analytics offer one way to do this, but if you want custom application behavior, then third party cookies are probably the way to go.
Firefox (at least my version of firefox, without any add ons or options changes) treats third party cookies much the same as first party cookies; that is, they just work. However, IE requires a bit more hoop jumping, as they check the p3p compact policy. A compact policy is basically a header you set which looks like this: P3P: CP="CAO PSA CONi OTR OUR DEM ONL". I looked around for an easy explanation of what the various values are and how to set them in a coherent manner, but didn’t run into anything very useful. However, I finally stumbled on this tutorial, which points you to this IBM software, which you can use to create a compact policy. The tutorial also walks you how to use that software, which is not entirely intuitive.
As far as I can tell, IE doesn’t actually check for the existence of the corresponding policy file, nor does it care if the site does what the p3p header says it does, but it does require a valid compact policy.
After you’ve added that header, IE (versions 6-8) will accept your third party cookies.
[tags]third party cookies, compact policy, howto[/tags]
GWT widgets and code splitting, a match made in heaven
If you are writing a typical GWT application, which is monolithic and controls the entire viewport of the browser, you probably don’t want to read this post. Go on, read something else interesting–you probably have emails or tweets or something better to do with your time.
OK, now we just have the people left who are using GWT to build widgets; that is small encapsulated pieces of functionality that integrate into an existing web based application (case #2 outlined here). If you’re doing this, and you use the “span to enable” gwt mini pattern, you want to upgrade to GWT 2.0 simply to get the new code splitting functionality. If you don’t want to read that previous link, the synopsis is that code splitting lets you define a number of pieces of distinct code, using GWT.runAsync. Then, that code won’t be downloaded until it is reached.
Previous to this feature, if you had a number of widgets, you ended up with a large chunk of code to download on every page (this is an issue with GWT that the monolithic applications simply don’t have to deal with). Some of that code will be run. Some will not, but you’re still paying for download and parsing of that code. You had some unsavory options to deal with this–let all the code be downloaded, or manually split up code into separate modules that you managed (either by hand or with deferred binding). The second solution led to smaller downloads, but meant a lot more management–if you wanted to add a widget to a page, you not only had to add the enabling span, you had to recompile the entire GWT module–and much longer compilation when you deployed your entire web application. However, if your widgets were static, this path might have been an option.
My client used the former solution (entire code download on every page), and was very excited about the code splitting, since that essentially automates the second choice above. In the space of about one half hour, I was able to reduce the initial download size of the GWT javascript by 10%, and there’s scope for much more, since the code is pretty naturally split up into separate chunks for each widget.
It’s not perfect, however. The two concerns I’ve had so far:
- The XS linker is not supported. This means that if any of your widgets need to be cross domain, you need to create an additional module specifically for that. For example, if I have one module, A, which is used to start up all the widgets on the site, and inherits from both module B, which has some GWT code split calls, and module C, which needs to be cross domain, the compiler will error out when compiling module A. I need to create a second module XSModuleC which inherits from module C and is compiled by the XS linker, and then use that module for all cross domain purposes.
- If you call
GWT.runAsyncfrom an event handler, like onClick, you will not have a valid event on the first call (when the module is loaded) but will on all subsequent calls. This is easy to fix, but was a bit mystifying to me. Basically, if you have code like this:
onClick(ClickEvent event) {
if (event.getSource() instanceof Image) {
// do something with image
}
}
you need to replace it with:
onClick(ClickEvent event) {
if (event.getSource() instanceof Image) {
// save event.getSource into an instance variable
GWT.runAsync(new RunAsyncCallback() {
// do something with image in instance variable
}
}
}
I'm sure there are other complications I'll find once I do more code splitting. (Here's an interesting post about code splitting in large applications, and simplifying the API of code that is split (plus, you get to see the word cromulent in context).) But, for now, code splitting and GWT widget development seem like a match made in heaven.
[tags]gwt,code splitting[/tags]
Whitespace and tables in IE
I was using the excellent displaytag library recently, and had written a table decorator to append some information about each row for a GWT widget to read and use. The table ended up looking like this:
<table>
<tr>
<td>data</td>
…
</tr>
<script type=”text/javascript”>var …</script><span id=’uniqid’ style=’display:none’>gwt config data</span>
<tr>
<td>data</td>
…
</tr>
<script type=”text/javascript”>var …</script><span id=’uniqid’ style=’display:none’>gwt config data</span>
…
</table>
This worked fine in Firefox and Safari, but IE (versions 6, 7 and 8 ) were displaying whitespace above the table. I couldn’t figure out why, until I commented out the table and the whitespace went away. Then I re-enabled the table, and commented out the finishRow method; the whitespace was still gone.
The answer, of course, is that IE doesn’t like stuff outside of the <tr> tags. Once I wrapped the span tag in <tr><td> tags, the whitespace went away for all browsers:
<table>
<tr>
<td>data</td>
…
</tr>
<tr><td><script type=”text/javascript”>var …</script><span id=’uniqid’ style=’display:none’>gwt config data</span></td></tr>
<tr>
<td>data</td>
…
</tr>
<tr><td><script type=”text/javascript”>var …</script><span id=’uniqid’ style=’display:none’>gwt config data</span></td></tr>
…
</table>
[tags]ie html quirks[/tags]
What to do when you get 504 and 500 errors from your Google Mini
I have a client who uses a Google Mini (a search appliance created by Google) as a key part of their business. The appliance worked fine, gave great search results, and was happily humming along until very recently. At some point over the last couple of months, the number of 504 errors visible to the users using the mini increased drastically.
At one point, no matter what term you searched on, you would see this error message:
Error: Unknown XML result type. View page source to see the offending XML. 504
When I took a look at this to try to troubleshoot, the results were very arbitrary--some search terms would show this message, some would not. However, when a search term did show the error message, it would do so consistently, at least for 5-10 minutes. Perhaps that had to do with caching?
The benefit of the mini is that you get great google like search results. The detriment is that it is a black box--you don't even get a login to the box, etc. And when your support contract runs out, you're left with very few options.
So, we troubleshot with one hand tied behind our back. We:
- tried rebooting the box a couple of times (via the web interface)
- considered rolling back the index, but we only had about 36 hours of index history
- generated and analyzed the search logs
- searched the Google Groups for mini support. All that turned up was this post which was not exactly helpful, since we no longer had support
Finally, the client suggested resetting the index, as it was conceivable that the mini index had been somehow corrupted. This was an option for the client because their documents are re-crawled every day. If that wasn't the case, it would have been a harder decision.
Resetting the index solved the problem. Some numbers:
- a few months ago, 0.5% of search requests were returning either 500 or 504 errors.
- just before the index was reset, 40.2% of the requests were either 500 or 504 errors.
- now, 0% of requests are either 500 or 504 errors.
FYI, this post is applicable to the Google Mini version 4.6.4--I'm not sure how more current versions of software work/break.
[tags]google mini,black box troubleshooting,504 error[/tags]
List of Front Range Software Networking Events and Conferences
Updated March 21: crossed out ‘conferences’ because I don’t do a good job of listing those.
Boulder, Colorado, has a great tech scene, that I’ve been a peripheral member of for a while now. I thought I’d share a few of the places I go to network. And by “network”, I mean learn about cool new technologies, get a feel for the state of the scene (are companies hiring? Firing? What technologies are in high demand?) and chat with interesting people. All of the events below focus on software, except where noted.
NB: I have not found work through any of these events. But if I needed work, these communities are the second place I’d look. (The first place would be my personal network.)
Boulder Denver New Tech Meetup
- 5 minute presentions. Two times a month. Audience varies wildly from hard core developers to marketing folks to graphic designers to upper level execs. Focus is on new technologies and companies. Arrive early, because once the presentations start, it’s hard to talk to people.
- Good for: energy, free food, broad overviews, regular meetings, reminding you of the glory days in 1999.
- Bad for: diving deep into a subject, expanding your technical knowledge
User groups: Boulder Java Users Group, Boulder Linux Users Group, Rocky Mountain Adobe Users Group, Denver/Boulder Drupal Users Group, Denver Java Users Group others updated 11/12 8:51: added Denver JUG
- Typically one or two presentations each meeting, for an hour or two. Tend to focus on a specific technology, as indicated by the names. Sometimes food is provided.
- Good for: diving deep into a technology, networking amongst fellow nerds, regular meetings
- Bad for: anyone not interested in what they’re presenting that night, non technical folks
Meetups (of which BDNT, covered above, is one)
- There’s a meetup for everything under the sun. Well, almost. If you’re looking to focus on a particular subject, consider starting one (not free) or joining one–typically free.
- Good for: breadth of possibility–you want to talk about Google? How about SecondLife?
- Bad for: many are kind of small
- Get together in a bar and mingle. Talk about your startups dreams or realities.
- Good: have a beer, talk tech–what’s not to like?, takes place after working hours, casual
- Bad: hard to target who to talk to, intermittent, takes place after working hours.
- Originally started, I believe, in response to FooCamp, this is an unconference. On Friday attendees get together and assemble an interim conference schedule. On Saturday, they present, in about an hour or so. Some slots are group activities (“let’s talk about technology X”) rather than presentations. Very free form.
- Good: for meeting people interested in technologies, can be relatively deep introduction to a technology
- Bad: if you need lots of structure, if you want a goodie bag from a conference, presentations can be uneven in quality, hasn’t been one in a while around here (that I know of)
Ignite
- Presentations on a variety of topics, some geeky, some not. Presentations determined by vote. Presentations are 20 slide and 5 minutes total. Costs something (~$10).
- Good: happens in several cities (Denver, Boulder, Fort Collins) so gives you chance to meet folks in your community, presentations tend to be funny, wide range of audience
- Bad: skim surface of topic, presentation quality can vary significantly, not a lot of time to talk to people as you’re mostly watching presentations
- Run by the CU CS department, these are technical presentations. Usually given by a visiting PhD.
- Good: Good to see what is coming down the pike, deep exposure to topics you might never think about (“Effective and Ubiquitous Access for Blind People”, “Optimal-Rate Routing in Adversarial Networks”)
- Bad: The ones I’ve been to had no professionals there that I could see, happen during the middle of the work day, deep exposure to topics you might not care about
- Cooperative work environments, hosted at a coffee shop or location.
- Good: informal, could be plenty of time to talk to peers
- Bad: not sure I’ve ever heard of one happening on the front range, not that different from going to your local coffee shop
- From the website: it “encourage entrepreneurs, developers and investors to organize real-world informal meetups”. I don’t have enough data to give you good/bad points.
- BarCamp with a focus–build a startup company. With whoever shows up.
- Good: focus, interesting people, you know they’re entrepeneurial to give a up a weekend to attend, broad cross section of skills
- Bad: you give up a weekend to attend
- Another group that leverages meetup.com, these folks are in Denver. Focus on web developers and designers. Again, I don’t have enough to give good/bad points.
Except for Ignite, everything above is free or donation-based. The paid conferences around Colorado that I know about, I’ll cover in a future post.
What am I missing? I know the list is skewed towards Boulder–I haven’t really been to conferences more than an hours drive from Boulder.
Do you use these events as a chance to network? Catch up with friends? Learn about new technologies, processes and companies?
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