libdb2.so.1: cannot open shared object file: No such file or directory – … ibm_db.so

Got this error while deploying a Rails app on Nginx: libdb2.so.1: cannot open shared object file: No such file or directory - ... ibm_db.so This means that the ibm_db adapter is installed, but it can't find the DB2 libraries. The issue is that IBM_DB_HOME and some other environment variables are not set. The best solution … Continue reading libdb2.so.1: cannot open shared object file: No such file or directory – … ibm_db.so

Circular dependency detected while autoloading constant

I recently ran into this frustrating and intermittent error in Ruby on Rails 4 (JRuby, actually): Circular dependency detected while autoloading constant Googling turned up several articles advising one to abide by the Rails conventions, but that was not the issue. The application I'm writing uses background threads. The problem shows up when trying to … Continue reading Circular dependency detected while autoloading constant

Userscript to make banning MediaWiki spammers easier

Somehow, I've come to be responsible for administering two MediaWiki-powered wikis. The main burden is having to ban spammers, which sometimes sign up in batches of 20 at a time. To help with process, I've put together the following browser userscript. On Firefox, you can easily set it up using the Greasemonkey extension. Opera and … Continue reading Userscript to make banning MediaWiki spammers easier

DB2 Express-C 9.7.5 released with Oracle compatibility

My team just put out DB2 Express-C 9.7.5. The big new feature is Oracle compatibility, which is now available in the free edition. It includes PL/SQL, CLPPlus, and other related things. DB2 Express-C is a free database. It's fairly straightforward to install on your own machine or deploy on a public cloud like Amazon EC2 … Continue reading DB2 Express-C 9.7.5 released with Oracle compatibility

SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing

I've written about issues related to "SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing" before, but I thought I'd add a few short notes. Your machine needs to be able to ping itself. If it can't ping itself, it can't DB2 itself either. The output of hostname, db2set -all, and cat … Continue reading SQL6048N A communication error occurred during START or STOP DATABASE MANAGER processing