Archive for March, 2010
Monday, March 29th, 2010
Instead of making a post about Linux solutions (or Linux itself) today, I thought I’d share the fruits of my Friday with you. Friday morning and afternoon was rather uneventful, so I decided to get out of the office early for an emergency fishing trip. I call this trip an emergency trip, since the rivers have recently thawed, and I renewed my Montana fishing license on the day before. Since “all work and no play makes Chris a dull boy”, I was determined to make the most of an otherwise dull day.
Luckily, the Yellowstone and Stillwater rivers are a quick 20 minute drive from my office, so I was able to spend about four hours fishing. With the wind chill at 38 degrees, I was comfortable with a cap and hoodie. The wind was blowing at gusts of 20 MPH, which made casting at times difficult. While we’re on the topic of casting, I’d like to mention that I was using minnow lures, and an assortment of flies tied to a floater. Not exactly the fanciest way to catch trout, but it works!
 Two Montana Rainbow Trout What you’re looking at are two of the four fish that I caught on Friday. I never thought to take a picture of the third (a 14 inch trout), and the fouth trout for the day was let go (less than 12 inches). The trout on the left is about 15 inches, while the trout on the right is 17 inches. The average size for Rainbow Trout in Montana is right about 13-16 inches, for what that is worth.
Since I never went to culinary school, and my wife is the chef in the house, I will probably cook these beauties using possibly the easiest trout recipe ever:
Easy Trout Recipe
Ingredients:
- trout (duh), cleaned and left whole
- lemons
- black pepper
- cayenne pepper
- olive oil
Directions:
- Coat the trout in oil lightly, while sprinkling black cayenne pepper on the outside of the fish.
- Cut lemons into wedges, and insert one wedge into the trout’s cavity.
- Wrap the trout in aluminum foil, and cook at 375 degrees in the oven for 20 minutes total, flipping the trout in the oven after the first 10 minutes.
- Once cooked, remove the trout from the foil, and gently scrape the fish off of the bones. Enjoy!
Hopefully next my blog post will be about something Linux related- but until then, good luck fishing!
Tags: Montana, Rainbow Trout
Posted in Personal | No Comments »
Monday, March 22nd, 2010
Is your Linux server down?
This one question has the power to keep us all up at night. Linux servers host your websites, handle your email, and manage your network. Your Linux server is the heart and soul of an online presence, since your databases and web applications all run on top of your server. Put simply, if your server is down, so is your business. Downtime means lost sales, and lost customers (present and future revenue). If you can’t afford downtime, you need a good server monitoring program. One such software solution is called Nagios, and it’s quite powerful.
Although Nagios isn’t the easiest web-based software solution to install (most of the server configuration is done by editing configuration files), it is extremely easy to use, once configured. Nagios presents you with a web-based status screen, which allows you to quickly view the status of all of the servers that you are monitoring. Nagios isn’t for just Linux servers either, Windows servers can be added to monitor as well. Once you are logged into Nagios, you can view the detailed status for all of the monitored servers by clicking on the “Service Detail” link.
From here, you can view the detailed information about when Nagios last checked the status of a service running on your server, and view the results of that last check. Pretty boring stuff so far, since nothing is broken. Let’s break the POP3 service on our server, and see how Nagios reacts. Within one minute, Nagios has flagged the POP3 service as being in a “critical” state. Nagios requires four failed connection attempts (by default), before an alert is issued. This is important, since sometimes a request is dropped by a router in between Nagios and the destination server. The Internet is a crazy place, and sometimes traffic isn’t delivered to it’s destination in time. Therefore, Nagios will wait for four consecutive failures, before it issues an alert.
 Critical Alert Once Nagios has failed to connect to the server four consecutive times, the server is then placed into an alert status. From here, depending on your Nagios configuration, an email can be sent, a text message sent, or even a sound played through speakers connected to your Linux server.
 Nagios email alert Once we have successfully fixed the issue with the POP3 daemon on our Linux server, Nagios will remove the critical warning on the server, and place the server into an “OK” state. Once the monitored server’s status is changed to “OK”, emails and SMS text messages are once again sent, to inform everyone that the monitored server is fixed.
 Nagios SMS Text Message Alert In addition, the host status on Nagios is now displayed as “OK” on the service status page.
 Nagios Host Status OK In addition to monitoring, Nagios also supports the ability to create logs and uptime graphs which display host uptime and service stability in an easy to read format. Host state breakdown reports allow you to easily view and export server and service uptime reports.
 Nagios Host State Breakdown Report In addition, you can also schedule downtime with Nagios, so that alerts aren’t issued when a service or server is taken down for routine maintenance. The downtime window is completely custom, and Nagios gives a summary of all planned downtime, by clicking on “Downtime”, on the navigational bar.
 Nagios Scheduled Downtime In the end, Nagios has the potential to save you both time and money. WIth Nagios, you won’t have to worry about whether or not your server is working- Nagios will let you know as soon as your server is unavailable.
Tags: nagios, web-based software
Posted in Cool Software | 1 Comment »
Monday, March 8th, 2010
This weekend, I wrote yet another article, Linux Mail Server Software- A Comparison of Popular Mail Transfer Agents. I wrote this article, since many of my clients often ask me what the best Mail Transfer Agent, or MTA would fit their needs best. Although the article brings up some good points, it doesn’t get into a great amount of detail (as articles rarely do) about the different features of the many available MTAs. Here are some additional points:
- Qmail’s license is not an open source license, but instead is licensed under the public domain. As such, it does not come with a copyright license, which may restrict the ability to distribute Qmail.
- Postfix is easier to extend, with support for Sendmail’s milters. For instance, enabling DKIM support for Postfix is trivial.
- Although Postfix is faster at sending large volumes of email than Exim (“out of the box” configuration), You can easily improve Exim server performance.
- I’m still trying to figure out why Sendmail is still used on Red Hat Enterprise Linux (and why it is still the most popular MTA)- Sendmail is definitely going the way of the dinosaurs- with it’s cryptic configuration, and security nightmares.
- Zimbra, while not a fair comparison against the others, excels in group collaboration. I’ve never had a client disappointed with it’s feature set, or performance. While not the best solution for a high volume mail server, Zimbra is very good at making email easier to use, and more powerful (without that dreaded Exchange).
I’ll stop short of recommending a “one size fits all” solution- in the end, it all matters on YOUR needs, not the software itself. There is no true winners or losers- just different solutions. As always, feel free to contact me if you have any questions about which solution meets your needs better.
Here is the article:
http://linuxconsultant.info/tutorials/linux-mail-server-software.html
Tags: Linux Mail Server Software, Linux MTAs
Posted in Online Additions | No Comments »
Monday, March 1st, 2010
One cool web-based software solution that I’ve stumbled upon lately is OpenEMM. OpenEMM is a mass mailing software solution for email marketing, sending newsletters, and mass mailing. Although I’ll admit that my experience with this particular niche of software is limited (I’ve installed and used SugarCRM, and PHPlist in the past), I’m really in love with OpenEMM’s layout and organization. Where OpenEMM really shines is the ability to quickly setup a campaign or single mailing event, and start to get emails flowing. OpenEMM contains it’s own email system (more on that later), so it’s basically self contained.
To get started with sending emails through OpenEMM, you first must create a “mailing”, which can either be a part of a campaign, or by itself (a cool feature when testing this software). After you complete a short wizard, you can fine tune the mailing very easily:
 Creating a mailing in OpenEMM Once you get the Mailing setup in OpenEMM, you can then add email addresses, or recipients, into OpenEMM (maybe it’s best to add those first, but it’s more fun to create the mailing first- it doesn’t really matter which order you do them in). One really nice feature, as you can see, is that it’s short and to the point- if you just want to add email addresses and get on with your life, OpenEMM does a very nice job of that!
 Adding an email address in OpenEMM Moving on, we also have the ability to create a template in OpenEMM to use for our mailings. This is nice, since the templates look professional, clean, and can be configured using variables for database variables (such as first and last names). I hate the impersonal feeling of mass mailing, and the inclusion of this feature is nice.
 OpenEMM email template Speaking of editing templates, OpenEMM allows you to preview how your template will look at different resolutions. This feature is really nice, since I use static table sizes in my designs, and I’m always curious as to how the border regions of tables look at higher/lower resolutions.
 Template preview feature in OpenEMM Now that I’ve talked up OpenEMM enough to sound like a commissioned salesman, let’s talk about some of the disadvantages:
- OpenEMM doesn’t appear to support an external mail server- you can either use the mail server built into the server that OpenEMM is installed on, or you can use the bundled mail server.
- OpenEMM’s mail server doesn’t always work 100% out of the box. If you want to switch mail servers, there isn’t a graphical way to do this. It would really be nice to have an “email server configuration” page built into OpenEMM. That way, I could use a mail server that is located on another server.
- OpenEMM requires the installation of Java from Sun, and also a user account created. OpenEMM isn’t the easiest mass email marketing software to install.
However, none of these disadvantages are particularly crippling. Time wise, I would say that it took me about an hour or so to install. Although I’m just playing with mass email marketing software at the moment, if I ever do decide to take the plunge and get started, OpenEMM will definitely be the software that I will use.
Tags: mass mailing software, OpenEMM, web-based software
Posted in Cool Software | No Comments »
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