Archive for the ‘Software’ Category

Bookmark: Oracle 11g JDBC driver hangs blocked by /dev/random – entropy pool empty

Saturday, March 22nd, 2014

Original post on Uson’s IT Blog

On a headless (==without console) network server, the Oracle 11g JDBC driver used for (Java) application connections may cause trouble. In my case, it refused to connect to the DB Server without providing any error, trace or log entry. It simply hung. After several hours, it connected one time, and froze again.

Tagged database, development, java, public via Pocket, added: March 18, 2014 at 10:35PM

Some days, I love the Internet!

Monday, April 2nd, 2012

So I was having a problem with a cygwin installation. I couldn’t figure out what was going on. Two minutes of googling later, I’d found someone with my exact problem, who had solved the problem and posted to the cygwin mailing list:

I just wanted to post this in case someone else runs into this issue like I did.”

Thanks, William Voyek!

The moral of this story:

Google is Awesome (given the right search terms, and sometimes even without the right search terms, it finds what you want a lot of the time… quickly).

Open Source is awesome. (How else could you get a nearly complete Unix environment running on a proprietary OS like Windows?)

Collaboration is Awesome (William posted just because he wanted to help others)

CUUG Talk on Cloud Computing

Wednesday, February 9th, 2011

I’ll be giving a talk at the February 22, 2011 Calgary Unix User’s Group (CUUG) meeting, updating my previous talk to CJUG two years ago.

Cloud Computing

Speaker: Tom Malaher, NetStart Consulting Ltd.

What is Cloud Computing? This talk will survey the landscape (cloudscape?), try to define cloud computing, where and how it can be used, and demo some live code running on one of the more mature offerings in a relatively new industry: Amazon Web Services or AWS.Tom Malaher has been working in the IT industry for 20+ years as a developer (C, Perl, Java, Web, SQL) and system administrator (almost every flavour of Unix known to man, and Windows only in self-defence). His current role is as an architect and back end integration (aka “glue”) developer.

Bow Valley College

332 – 6 Ave S.E.Room N-438

5:30 PM, Tuesday, February 22, 2011

Free admission for the general public.

Digital Archaeology: Macintosh floppies circa 1986

Saturday, December 18th, 2010

Cleaning up the office a bit, came across a box full of Mac floppies, left over from my original Mac.

It was a “Fat Mac” Business Bundle, 512K RAM, 2 400K (single sided!) floppy drives, keyboard with numeric keypad (default keyboard had no numeric keypad). At the same time I got Macintosh Pascal and the Macintosh Programming Guidelines book (which was the size of a phone book and printed on similar low-grade thin paper).

Total cost: $3,512.25 in about 1986 (and that was the student discount price!) purchased from the University of Manitoba bookstore.

Here are some of the floppies.

Macintosh Floppies circa 1986

Five of them likely came with the original machine.

The one labelled “Macintosh Plus System Tools” is from later (note that it says “double sided”) after I had upgraded the machine to a Mac Plus (swap out the system board and upgrade the floppies to double sided: 800K!).

Note the handwritten version numbers: Finder 5.1, System 3.0, and DAM 3.0, whatever the heck that was. Some disks were bootable (i.e. they had System and Finder on them) while others were not, so it was important to know which were which (“System and Macwrite Macpaint”) and what version they were (cf. my “NotUpd” notation on the Macwrite/paint disk and my “Upd” notation faintly visible on the Mac Pascal disk).

I wrote my thesis on this machine, using Word 3.0 for the Mac. I have the floppies somewhere, and was able to get the files off them, but I’ve been unable to reconstruct the text of the document, let alone the formatting. Luckily I have a nice hardcover version on the bookshelf.

Cloud Computing Presentation

Friday, March 13th, 2009

The presentation went well, the Elluminate software worked just fine. People reported good audio quality, and the features like “raise hand” and the chat window allowed for questions to be asked and answered during the presentation.

The screen sharing seemed to behave as expected.

I’ve made the presentation slides available for dowload: Cloud Computing Presentation to CJUG March 2009

A recording of the actual presentation is available at CJUG’s web site.

Cloud City Background

Calgary Java Users Group presentation on Cloud Computing – March 11, 2009

Monday, March 9th, 2009

I’ll be giving a presentation on Cloud Computing at the Calgary Java Users Group meeting on March 11, 2009 at 5pm MDT.

What is Cloud Computing? Every vendor seems to define it differently.

Last month’s CJUG speaker (Nikita Ivanov from GridGain) talked about how to more easily use cloud computing resources for grid computing. Of course he gave his own definition of Cloud computing…

But let’s step back a moment and try to figure out what cloud computing is all about.

This talk will survey the landscape (cloudscape?), try to define cloud computing, where it might be used, and demo some actual Java code running on one of the more mature offerings in a newborn industry: Amazon Web Services or AWS.

The presentation will actually be Virtual, using screen-sharing/conferencing software from Elluminate. If you’d like to attend, I suggest you visit the Elluminate First Time Users page to ensure your computer is configured correctly ahead of time. Be sure to go to the “Configuration Room” to set up your audio.

Note: For those of you behind corporate firewalls that need to use a proxy server, I did have some difficulty with this initially, but following these instructions: Proxy use with Elluminate Live, I was able to get it working. Specifically, I set my Java to use a hard-coded proxy server, and then when I ran the application, it still could not connect, and I then used the instructions in Step 3 (Manual proxy settings), after which things worked fine.

To quote from the CJUG page:
To join the meeting, click on this link. The Elluminate Live! software will download and run via Web Start – make sure you have Java (preferably 5 or 6) installed and allow a few minutes for a download of approximately 15Mb. You can join the meeting any time from 4.45PM onwards.

Refactoring Dynamic Code

Monday, November 19th, 2007

This has been one of my concerns all along.

The claim is that “enough testing” will eliminate the need for the compiler to do static checking at compile time.

Frank Sommers seems to be saying otherwise… in the long run.

So, I’m feeling justified in my decision to stick with Java, where I gain maximal benefit from IDEs and compilers.

Rapid Web Development with NetBeans & EJB3 – Wed May 9th

Thursday, May 3rd, 2007

I’ll be presenting at the May 9th Meeting of the Calgary Java Users Group.

See you there!

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More on Searching

Thursday, March 29th, 2007

When I was presenting to the Calgary Java User’s Group about Building your own search engine, the topic of Egothor came up. I’ll have to check it out. See my previous comments on searching email.

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Password lockbox

Thursday, March 29th, 2007

With the advent of Sarbanes-Oxley, it seems everyone is hot to start changing their passwords on a regular basis. This is enough of a problem for people, but when systems need to use passwords to get things done automatically, it turns into a nightmare.

I started putting together a specification for a password “lockbox” that would handle this. It would have to be able to handle standalone machines that were their own security domain (e.g. Unix with local passwd file) or a group of machines that share the same password (e.g. NIS or AD). It would be nice if you could encode the password expiration policy and have the system automatically change the password for you so it wouldn’t expire. You’d want sophisticated ACLs to control who can see which passwords.

Yesterday I went to a presentation from a company about a product of theirs that seems to cover all of this and more: Cyber-Ark’s Enterprise Password Vault.

It’s not cheap, but on the old build-versus-buy continuum, I think this is one I’d rather buy.