Install pair of KVM servers for Web and DB

2010-09-13T01:21:00.000-07:00

This post is for my personal reference. I'm using custom scripts to manage the installation of KVM servers, so the information in here will probably not be useful to anyone else. Examine the files in /root/vmbuilder/appliances/mysql to see if anything needs updating. For instance, vmbuilder.partition may need to be adjusted. Also examine /root/vmbuilder/appliance/jetty files. If changes are

Server disk and raid problems

2010-09-10T21:48:00.000-07:00

I have two KVM servers that are pretty much identical, both running RAID1. I rarely log into the host systems, but did so today because I needed to create a new host on one of them. It turns out that I couldn't do anything because the host's drive had been set to read-only mode. I checked the other system, and it too was in read-only mode! Upon researching the problem, I found that sdb appeared

Using string-based property accessors in javascript

2010-07-28T12:46:00.000-07:00

When it comes to javascript development, I rely heavily on using plain javascript objects for data, often loading JSON data from an async server call. Below is some typical JSON that I might load after it has been processed into a plain javascript object. Note that the loaded data contains an array of users along with extra data is used for pagination purposes (count, page, and max).

My latest electronics purchase

2010-07-26T10:41:00.000-07:00

I just purchased a Pioneer VSX-1020-K Audio/Video Receiver. From what I've read online, it looks like it will totally meet the needs of my home theater. I will update this post once I have it set up and review it.

Problem with google-checkout-java-sdk and JDK1.6

2010-01-27T20:13:00.000-08:00

I was using google-checkout-java-sdk in a custom online shopping solution. When I switched the project's POM from java 1.5 to 1.6, it seems that google checkouts would no longer work. I was getting this error when attempting to send an order to Google Checkout:

Blog template updated, includes syntax highlighter

2010-01-26T15:45:00.000-08:00

I just updated my blog template to something that was wider, that's why it looks different now. I needed it wider to better display code snippets now that I added SyntaxHighlighter. I installed it by following Carter Cole's howto.

Using Wicket with Shiro for authentication and authorization

2010-01-26T01:05:00.000-08:00

In my Wicket application, I'm using Apache Shiro for both authentication and authorization. I needed powerful authorization features that would have taken a lot more work with Wicket alone. Personally, unless you have dead-simple requirements, I'd suggest learning how to do it with shiro and saving yourself some hassles in the future.To simplify integrating wicket with shiro, I created the

Repairing a corrupt eclipse workspace

2009-10-21T03:08:00.001-07:00

I've had Eclipse crash on me many times in the past and left things in a state where I couldn't get the workspace to start back up properly. Eclipse would lock-up when restarting. I have always fixed it by simply creating a new workspace and then rechecking out my projects from SVN. But that is a tedious process, and can be a real hassle.So this time I decided to find a better way. Victor

The fifth decade

2009-06-04T13:52:00.001-07:00

Wow. The day is here. I've officially completed my fourth decade of life and have began my fifth. I guess I don't really have a whole lot to say about it. This big 4-0 birthday seems pretty much just like any other day. But it has arrived, and now I'm no longer a 30-something. So here's to a happy and prosperous fifth decade!

Tool for encoding XML/HTML tags

2009-02-25T01:00:00.000-08:00

Here is a website that will convert all of your XML or HTML tags for display in a blogger post. Basically, it changes < to < and > to >. I'm sure it does a lot more than that too, but that is the most important things it does.http://www.centricle.com/tools/html-entities/

Configuring virtual hosts in Jetty

2009-02-25T00:14:00.000-08:00

I just figured out how to do virtual hosting in Jetty. I have a customer with two sites. The first site (I will call it webappsite.com) is running a java webapp on the root of the site and has a ROOT.war in the webapps directory. The second site (calling it staticsite.com) is currently just a static site. I wanted the site content for the static site to be easily accessible, so I put it into

Configuring SSH for behind a firewall

2009-02-24T19:00:00.000-08:00

My brother couldn't get connected to his websites in Fetch on his Mac and we figured out that the library he was at was blocking most ports except the most common ones. His VPS only allows connections via SSH/SCP/SFTP or HTTP. In the end, I configured sshd on his VPS to listen to port 21 (the standard FTP port) as well as port 22. Since FTP isn't running on his VPS, this worked fine. Then he

Removing messages from postfix mail queue

2008-04-30T12:05:00.000-07:00

Mail is backing up in the mail queue on my postfix server. I've found that many messages are ones I can remove, but I don't want to manually delete them one at a time. I found a posting on howtoforge that helped:http://howtoforge.com/delete-mails-to-or-from-a-specific-email-address-from-postfix-mail-queueHowever, the command didn't work, as I think it left the -n out of the tail command. So I

Hard drive crash

2008-03-08T16:58:00.001-08:00

I just lost a drive on a CentOS / OpenVZ server. The system had three 750GB sata drives, two of which were mirrored, and one spare. The sdb drive had failed and brought the system down when it did so. I thought a RAID1 system was supposed to keep running even if a drive failed. Evidently not, or at least not with linux software raid.Anyway, the spare drive was partitioned to be used as a

Firefox causes Wicket to re-render page

2007-12-21T12:20:00.000-08:00

I had a problem with my Wicket application where the page was being rendered twice, but the DOM in my browser wasn't getting updated. After much hair loss, I discovered it wasn't a wicket thing at all. Nor was it anything wrong with my application. It was something specific to Firefox.It turns out that Firefox makes an additional page request if there is an image on the page with an empty

Postfix problems after update

2007-10-25T12:55:00.000-07:00

One more thing to add to my last post:After the update, I also cannot send email. The error logs show this: Oct 25 11:55:19 mailhost postfix/smtpd[10671]: warning: SASL authentication failure: cannot connect to Courier authdaemond: Permission deniedOct 25 11:55:19 mailhost postfix/smtpd[10671]: warning: unknown[xx.xx.xx.xx]: SASL LOGIN authentication failed: generic failureWith a quick google I

Courier SSL problems after update

2007-10-24T13:46:00.000-07:00

I posted this message as a comment to the HOWTO I used to configure my mail server:http://www.howtoforge.com/fedora_virtual_postfix_mysql_quota_courierI've been running a mail server built using this HOWTO for a while now. I recently updated the entire server with a "yum update". Email clients could no longer connect to the server via POP3 or IMAP if SSL was enabled. I was getting errors like

Installing and configuring BIND/named

2007-10-12T14:55:00.000-07:00

This Configuring DNS HOWTO was very helpful for installing a new bind server.Also, their Linux firewall/iptables HOWTO was helpful as well.

Set up Apache as a reverse proxy

2007-10-10T16:51:00.001-07:00

Since my client's VPS doesn't have enough memory to run a servlet engine with their app, and we don't have time to move to a bigger VPS, I'm looking for interim solutions. One idea is to use their Apache server as a proxy server to an external server.Here's the situation. Their website has an SSL certificate with www.company.com in the domain. We can't move their site, and the SSL cert

Finding memory usage in Virtuozzo VPS

2007-10-10T16:39:00.000-07:00

I have a client who has a VPS at iPowerWeb. I can't say that I'm very thrilled with iPowerWeb, especially after finding javascript trojans scattered on pages throughout their site.Anyway, I needed to figure out how much memory is available to their VPS. I found some information here about it. I've consolidated the pertinent information below:Assuming your VPS provider is using UBC memory

Easy CRUD in Wicket

2007-09-21T18:12:00.000-07:00

I like Igor's implementation of wicketstuff-crud. Check wicketstuff svn for it. But there is also WicketWebBeans which looks interesting.

Open source solutions for a grid infrastructure?

2007-09-21T17:35:00.000-07:00

I've been searching for the last few days for any open source tools that could help in building an infrastructure for deploying grid or utility computing services. I haven't found anything yet that does everything, but maybe it is out there.The AppLogic product by 3Tera looks pretty cool. It uses a combination of open source and proprietary technologies, including Xen and NBD. Hosted solutions

Eclipse 3.3 configuration for Wicket with Aptana

2007-08-10T16:15:00.000-07:00

It turns out that using Aptana as the HTML editor in Eclipse marks all the wicket tags as errors. To get around this, do this:Go to Window->PreferencesSelect Aptana->Editors->HTML EditorAdd a new filter: .*wicket:.*Click OK

Configuring Eclipse 3.3 for wicket web development

2007-08-10T14:15:00.000-07:00

Install software updates and plugins------------------------------ Go to: Help->Software Updates->Find and InstallSelect: Search for updates of currently installed featuresAutomatically select mirrors (or manually do it if you prefer)I can't remember what I updated, but there is a minor Eclipse update availableInstall this update -- I think it is needed for WicketBench to work.When asked to

Eclipse 3.3 with subversion support

2007-08-10T14:01:00.000-07:00

Just installed Subversive plugin into eclipse 3.3. Using update feature, added new site:http://www.polarion.org/projects/subversive/download/1.1/update-site/In order to install, I had to remove the following feature:Subversive Integration for the CSC Project Set

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