Browsing articles from "September, 2010"

Dashboards and Displaying Business Data

Sep 24, 2010   //   by Mike McMurray   //   Interesting Stuff  //  No Comments

From Monolith Software blog, “even the best dashboards are somewhat myopic, and badly designed dashboards can lead to complacency, poor communication and eventually overlooked issues, degradations or outages.”

This is something that comes up repeatedly when displaying data from one area to those from the wider business. Data in any form needs to come with the required info or education to provide clarity. The most basic chart can be mis-interpreted by those who make assumptions on the colours, format, numbers, etc before them. Admittedly, providing clear, functional, beautiful dashboards of a business’s data is difficult – and that’s one of the key reasons I enjoy doing it.

Ignore Network Latency at Your Peril

Sep 19, 2010   //   by Mike McMurray   //   Interesting Stuff, Web Apps  //  No Comments

We all know developers need to consider a few things outside their own backyard. Things like hardware and the network affect software even if there’s not much that can be done to control them (even if you’re Apple). This is especially true for the network if you develop software for mobile devices.

So to help us all understand why the nuances of any network are important to all of us, Nic Wise has a good little blog post about what to keep in mind. It’s written in people language and not TCP layers, so we can all benefit from this one.

Watching your Network Usage

Sep 16, 2010   //   by Mike McMurray   //   Sys Admin  //  No Comments

I’m sure everyone else knows about the iftop tool, but it was new to me. I needed to confirm that traffic from DRBD was using a particular interface and iftop does the job by showing traffic sources, speed and culmulative data counts per interface.

The iftop tool shows you usage per interface

Missing Network Interfaces in Ubuntu Under VMware ESXi

Sep 16, 2010   //   by Mike McMurray   //   How-To, Sys Admin  //  4 Comments

Every now and again I clone a VM and add it to another host. ESXi prompts you for a new UID when you start the VM and I always remove the virtual network card(s) from the machine and re-add them later. I do this to make sure I don’t have two machines with the same MAC addresses on the network. But if you do this with Ubuntu, the new NIC(s) don’t get picked up by the OS. This is almost certainly not specific to VMware or their ESXi product, it’s just the environment I’m using.

This problem seems to be caused by a lack of automatic hardware probing at boot, probably for a good reason but I’m no Linux kernel guru so won’t make a judgement there. The root of the issue is located in the file /etc/udev/rules.d/70-persistent-net.rules where you’ll see the old interfaces still listed alongside the new ones. Simply remove the old NIC(s) and ensure the new ones have the MAC addresses you expect and the correct ethx labels. Give the system a reboot and you should be happy.

Steps to resolve a missing network interface in Ubuntu 10.04 Lucid Lynx (and possibly earlier):

  1. sudo nano /etc/udev/rules.d/70-persistent-net.rules
  2. Delete the lines with the old interfaces after comparing with your VMs newly assigned MAC addresses.
  3. Confirm the interface names are what you expect at the end of each line.
  4. Ctrl-X to save and exit.
  5. sudo shutdown -r now
  6. Run ifconfig to confirm the interfaces are up with the correct IPs.
  7. If the interfaces are up, check your /etc/network/interfaces config to adjust IP settings as required.

Kisimi: a wiki for normal people

Sep 14, 2010   //   by Mike McMurray   //   Web Apps Portfolio  //  No Comments

Kisimi is a free and simple Wiki, based on DokuWiki, with more than a few handy features that’s designed to look good and cover the basics.

What’s a wiki?

Pages in a wiki-enabled web site have the ability to be edited by anyone using pretty much plain text. This allows content to be added by people around the world, providing a collaborative space for your ideas and documentation. Each  change is tracked and credited to the different authors which allows for easy editing and infinite versions of each page.

A site running Kisimi can be used for things like simple note taking or a place to store ideas or technical documentation. Pages can be opened up to the world or restricted to you and your friends or colleagues. You can also upload your documents and images or other files for use in your pages. You don’t have to know anything about HTML or programming, just jump in and start writing.

Features of Kisimi include Privacy and Protection of pages and files and the concept of Ownership of categories (collections of pages). Changes to each page are saved with differences immediately available via History. To learn about other features, have a read through the Manual or suggest a feature on the Feedback page.

To see what Kisimi can do, try the SandPit. Anyone can make and save changes to these pages, although until you sign in you won’t be able to Protect pages, mark your own as Private or claim Categories.

Current Release

Kisimi version 20091025 has been released and is available for download (7zip, zip, tar.gz) now. Please check back here for the documentation and let me know how things go. Kisimi source code is made available under the GNU General Public License (GPL).

If you find a bug (we’re still working on perfection), would like a new feature or want to tell us your views, please use Mende to submit a Ticket, message mike from your Kisimi account, email kisimi@wekadesign.co.nz or visit the Feedback page.

Kisimi is best viewed with a modern web browser like Firefox, Chrome, Safari, Opera or Internet Explorer 8 (not IE6) at a minimum screen resolution of 1024×768. Feel free to send me an email with any feedback, kisimi@wekadesign.co.nz

The Name

The name Kisimi comes from Kisimi Kamara of Sierra Leone who created the Mende language of the region to encourage literacy among his people.

Overview System Monitoring

Sep 14, 2010   //   by Mike McMurray   //   Web Apps Portfolio  //  1 Comment

Introduction to Overview System Monitoring

The aim of Overview is to enable system administrators to monitor servers and other network devices and collect information. An Overview server can be configured to pull information from your devices or an agent can run on your device to pass encrypted data back. Once Overview has the data it can then make decisions on whether that data meets the required values. Almost anything can be read from the remote devices and you can expand on the remote scripts as required.

Overview has a number of features that can help out any system administrator, such as:

  • all data is collected and stored for graphical display, allowing you to spot trends and view historical usage.
  • any data collected can be queried to meet any conditions you specify and alert users if required.
  • can collect data on disks, CPU, RAM, network, ping, fileshares, file contents, databases, connected users, Citrix users, services, processes, print queues and more.
  • team members can be alerted to problems by email or TXT message within seconds.
  • alerts can be configured to wait a certain time to minimise false alarms or momentary conditions e.g. a CPU spiking to 100% for a few seconds.
  • the default dashboard shows the last alerts, most alerted devices and a breakdown of the last few days.
  • team members can roster themselves off to avoid alerts when required.
  • each data collector can be configured to only run at certain times or days of the week.
  • simple to use and easy to understand.
  • runs on free OSS (Apache, PHP, MySQL) and a Windows or Linux server meaning setup can happen in under 30min.

Currently Overview is undergoing testing in a production environment, and it’s planned to run a restricted version of it on a public website to let anyone use it.

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