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Displaying posts with tag: Linux (reset)
dpkg: dependency problems prevent configuration of mysql-workbench-community for Ubuntu 13.04

While installing mysql-workbench-community-6.0.9 on Ubuntu 13.04 if you get below error.

root@Dell-XPS:/home/nilnandan/Downloads# dpkg -i mysql-workbench-community-6.0.9-1ubu1204-amd64.deb
Selecting previously unselected package mysql-workbench-community.
(Reading database … 203112 files and directories currently installed.)
Unpacking mysql-workbench-community (from mysql-workbench-community-6.0.9-1ubu1204-amd64.deb) …
dpkg: dependency problems prevent configuration of mysql-workbench-community:
 mysql-workbench-community depends on libctemplate0; however:
  Package libctemplate0 is not installed.
 mysql-workbench-community depends on libgtkmm-2.4-1c2a (>= 1:2.24.0); however:
  Package libgtkmm-2.4-1c2a is not installed.

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Capturing MySQL Data with tcpdump

Percona Toolkit has a great tool, pt-query-digest, that can use tcpdump data. Capturing raw tcp data can be taxing on a server, however, when you see the following message:

64000 packets received by filter
12000 packets dropped by kernel

When there is a significant amount of user cpu% being used, the kernel will drop packets you are trying to capture, leading to a partial picture and missing data. I’ve found that if you write it using the native tcpdump format, it’s more efficient and you drop less. There are also recommendations on Stack Overflow on how to help prevent this.

To perform a capture for a specific length of time, here’s the trick I …

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Continuent, a leading provider of database clustering and replication software has five (5) new positions open:

Build/Test Engineer Senior Database Availability and Clustering Engineer Senior Database Replication Engineer Data Replication Sales Engineer Clustering and Replication Test Development Engineer

If you want to get in on the ground floor of a growing company in a challenging field

The joy of Unicode

So, back in late 2008, rather soon after we got to start working on Drizzle full time, someone discovered unicodesnowmanforyou.com, or:

Since we had decided that Drizzle was going to be UTF-8 everywhere,(after seeing for years how hard it was for people to get character sets correct in MySQL) we soon added ☃.test to the tree, which tried a few interesting things:

CREATE TABLE ☃; CREATE DATABASE ☃; etc etc

Because what better to show off UTF-8 than using odd Unicode characters for table names, database names and file names. Well… it turns out we were all good except if you attempted to check out the source tree on Solaris. It was some combination of Python, Bazaar and Solaris that meant you just got python stacktraces and no source tree. So, if you look now it’s actually …

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Why buffered writes are sometimes stalled

 Many people think buffered write (write()/pwrite()) is fast because it does not do disk access. But this is not always true. Buffered write sometimes does disk access by itself, or waits for some disk accesses by other threads. Here are three common cases where write() takes longer time (== causing stalls).
1. Read Modify Write Suppose the following logic. Opening aaa.dat without O_DIRECT/O_SYNC, writing 1000 bytes sequentially for 100,000 times, then flushing by fsync().

  fd=open("aaa.dat", O_WRONLY);
  for(i=0; i< 100000; i++) {
    write(fd, buf, 1000);
  }
  fsync(fd);

 You might think each write() will finish fast enough (at least less than 0.1ms) because it shouldn't do any disk access. But it is not always true.
 Operating System manages I/O by page. It's 4KB for most Linux environments. If you'd modify 1000 bytes of the 4KB page from offset 0, Linux first needs to read the 4KB …

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SSH Two-Factor Authentication with Duo Security

Over on the codecentric blog I published an article on SSH Two-Factor Authentication with Duo Security. You are welcome to check it out.

Open Source Enigma Project

The wild and crazy guys over at S&T Geotronics, James Sanderson and Marc Tessier, have decided to go full tilt with a Kickstarter version of their DIY Open Enigma Project.  For those who missed the fanfare last year, they were featured on Instructables showing how to build an Arduino-based encryption machine that works exactly like a WWII era Enigma.  You know, the thing that Alan friggin' Turing and his team at …

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Sandboxed MySQL Utilities – HowTo

Often I would need to work on customer servers where MySQL Utilities would be a really good fit for the tools I need. However, I would not want to mess around with the customer servers just to have it running so I would have the tools built and sandboxed on its own directory where I can cleanup later. Here’s how:

cd ~
wget http://mysql.mirrors.hoobly.com/Downloads/MySQLGUITools/mysql-utilities-1.4.1.tar.gz
tar xzf mysql-utilities-1.4.1.tar.gz
cd mysql-utilities-1.4.1
python setup.py build
python setup.py install --root=/home/revin/mysql-utilities-1.4.1
export PYTHONPATH=.:/home/revin/mysql-utilities-1.4.1/usr/lib/python2.6/site-packages
/home/revin/mysql-utilities-1.4.1/usr/bin/mysqlfrm --help

Your source of the package and install directory may vary – enjoy!

Mac Mini to the rescue

In teaching, I had a problem because my students have different base operating systems, like Windows 7, Windows 8, Linux, and Mac OS X. I needed a teaching and lecture platform that would let me teach it all (not to mention support their environments). That meant it had to virtualize any of the following with a portable device:

  • Windows 7 or 8 hosting natively an Oracle Database 11g XE, 11g, or 12c and MySQL Database 5.6
  • Windows 7 or 8 hosting a Fedora or Oracle Unbreakable Linux VM (3 or 4 GB) with Oracle Database 11g XE, 11g, or 12c and MySQL Database 5.6
  • Mac OS X hosting a Fedora or Oracle Unbreakable Linux VM (3 or 4 GB) with Oracle Database 11g XE, 11g, or 12c and MySQL Database 5.6
  • Ubuntu hosting a Fedora or Oracle Unbreakable Linux VM (3 or 4 GB) with Oracle Database 11g XE, 11g, or …
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and now for something completely different…

As many of you know, I’ve been working in the MySQL world for quite a while now. IN fact, it was nearly 10 years ago when I first started hacking on MySQL Cluster at MySQL AB.

Most recently, I was at Percona which was a wonderful journey where over my nearly three years there the company at least doubled in size, launched several new software products and greatly improved the quality and frequency of releases.

However the time has come for something completely different. The MySQL world is rather mature, the future of …

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