Interesting error found on Oracle XE installed for one of projects. After a run of test case that uses JDBC to perform some operations on database all tests started to fail with this exception:
Caused by: java.sql.SQLException: ORA-00600: internal error code, arguments:\
[kdsgrp1], [], [], [], [], [], [], []
at oracle.jdbc.driver.DatabaseError.throwSqlException(DatabaseError.java:112)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:331)
at oracle.jdbc.driver.T4CTTIoer.processError(T4CTTIoer.java:288)
at oracle.jdbc.driver.T4C8Oall.receive(T4C8Oall.java:743)
at oracle.jdbc.driver.T4CPreparedStatement.doOall8(T4CPreparedStatement.java:216)
at oracle.jdbc.driver.T4CPreparedStatement.executeForRows(T4CPreparedStatement.java:955)
at oracle.jdbc.driver.OracleStatement.executeMaybeDescribe(OracleStatement.java:1062)
Restart of Oracle database did not work. Seems table space was broken. I rebuit the database (DROP, then CREATE) and error dissapeared.
Interesting …
What’s the purpose of internal project documentation? To help people do their jobs. Developers need the knowledge to be distributed across the team, testers need definition of proper system behaviour, marketing needs information on product features to sell it.
Questions
Important knowledge that may be required by developers doing updates may be summarized in few sentences:
- Who changed recently that line of code?
- When this method have been changed?
- Why algorithm works that way?
There’s simple method of automatically saving and retrieving this kind of information: Subversion (or any other version control system). How?
(more…)
I just got an email from my monitoring system:
Site: http://twitter.com is down ('502 Bad Gateway')
Looked at main Twitter page and saw this picture:
I checked that Twitter responds very slowly and randomly shows “over capacity” page. You can see details on site-uptime public report. Here’s response graph from last days (measure interval 15 minutes, HEAD requests):
UPDATE (2010-04-15): after few weeks the situation is getting worse:
Google AdWords is popular marketing tool that allows you to attract customer attention. You “pay per click” – that means if potential customer is directed to your page (or e-commerce site) then you will pay.
There are two main variations of this tool:
- matching advert is located based on keywords entered by user in Google search
- matching advert is located based on content of a partner page (AdSense partner)
It seems both methods (keyword and content-based) are equal efficient, but wait: there’s a big difference. When user is searching for some keywords it’s very likely he will be interested in your product/service. When user is coming from AdSense page he may be directed to this page for different reason.
(more…)
Recently I’ve registered an account on twitterfeed.com site that forwards blog RSS-es to Twitter and Facebook accounts. Headers of incoming mail attracted my attention:
Return-Path: root@mentiaa1.memset.net
(...)
Received: from mentiaa1.memset.net (mentiaa1.memset.net [89.200.137.108])
by mx.google.com with ESMTP id 11si7984998ywh.80.2010.02.12.06.24.18;
(...)
Received: (from root@localhost)
by mentiaa1.memset.net (8.13.8/8.13.8/Submit) id o1CERcGq004355;
(...)
From: noreply@twitterfeed.com
(...)
Interesting parts are bolded out. As you can see registering e-mail was sent from root account. Probably the same user id is used for WWW application. That means if you break the WWW application you can gain control over whole server.
The preferred way to implement WWW services is to use account that has low privileges (www-data in Debian) because breaking the service will not threat whole server.
