A few days ago, I was struggling to install python on a Linux machine, in which I had no root permission. That machine was shared with many other users and there was only an old python version already installed on the machine. After a bit of search and trial, I was able to install a newer version of python on this machine to my local directory.

My goal was to run a program developed under python 2.7 on the Linux server which already had python 2.6 installed. As you can see, it was impossible for me to upgrade python on the system because I had no root permission. The only solution was to install the python 2.7 into my local directory and override the necessary environment variables. Even though this blog aims for python 2.7, I believe it should also be the same for python 3.0. The detailed steps are as follows:

1. Install python to local directory

Firstly, I create a folder in my home directory, download the …

In this blog post, we’ll discuss some of the basics regarding Docker MySQL replication. Docker has gained widespread popularity in recent years as a lightweight alternative to virtualization. It is ideal for building virtual development and testing environments. The solution is flexible and seamlessly integrates with popular CI tools.

This post walks through the setup of MySQL replication with Docker using Percona Server 5.6 images. To keep things simple we’ll configure a pair of instances and override only the most important variables for replication. You can add whatever other variables you want to override in the configuration files for each instance.

Note: the configuration described here is suitable for development or testing. We’ve also used the …

We have been using SSH all the time but not all people really understand the files we put inside the ~/.ssh folder on our computer. It was a myth to me when I was first using SSH, but things are pretty clear to me now and I want to share this with all of you, just in case you don't know.

known_hosts

This file is responsible for verifying the host we have connected to. If it was the first time you connect to a host, you would probably see the following message:

The authenticity of host 'example.com (10.0.0.0)' can't be established.
RSA key fingerprint is    SHA256:VqgUG8v+gxrigR1csELYv6Un6l7HxMgPgMj9wyUr7G4.
Are you sure you want to continue connecting (yes/no)?

The moment you select yes to continue connecting, the hostname along with the public key of the server will be saved as a new line in this file. Why we need this file? Just imagine that for some reason our routing has …

In my previous post, I spoke of "Normalized" and "Non-Normalized" CPU utilization values:
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TABLE:Foreword: Windows is not "process" based OS (like Linux) but rather "thread" based so all of the numbers relating to CPU usage are approximations. I did made a "proper" CPU per Process looping and summing up Threads counter (https://msdn.microsoft.com/en-us/library/aa394279%28v=vs.85%29.aspx) based on PID but that proved too slow given I have ~1 sec to deal with everything. CPU utilization using RAW counters with 1s delay between samples proved to produce a bit more reliable result than just reading Formatted counters but, again, too slow for my 1s ticks (collect sample, wait 1s, collect sample, do the math takes longer than 1s). Thus I use PerfFormatted counters in version 0.9RC.

Win32_PerfRawData_PerfProc_Process;  …

I use Pingdom's free service to monitor slaptijack.com. Apparently, late Friday night, oom-killer decided that the server needed more memory and took out the MySQL server. To make matters worse, I missed the alarm from Pingdom, and slaptijack.com was down for pretty much all of Saturday. The fact that oom-killer was invoked is annoying, but more on that later.

The beauty of using Pelican rather than Wordpress (or any other database-driven content engine) is one less point of failure for the site. Obviously, I don't have all of slaptijack.com converted to Pelican yet (and perhaps never will), but at least parts of the site were up and working despite MySQL being down. If nothing else, this incident is enough to convince me that moving to Pelican was a good idea.

OOM'ed

…

As per redis home page,

"Redis is an open source (BSD licensed), in-memory data structure store, used as database, cache and message broker. It supports data structures such as strings, hashes, lists, sets, sorted sets with range queries, bitmaps, hyperloglogs and geospatial indexes with radius queries."

Redis Installation Steps:

I am trying the below steps in an ubuntu 14.04 system. Open the terminal and issue the below commands:

1. Get the latest tar zip for redis (http://redis.io/download)

$ cd /path/to/download/directory/
$ wget http://download.redis.io/releases/redis-3.0.7.tar.gz

2. Untar it and issue below commands:

$ tar xf redis-3.0.7.tar.gz$ cd redis-3.0.7$ make$ sudo …

Welcome to the final blog in Windows PerfCounters and Powershell series and sorry for the delay. The purpose of this blog is to explain the inner workings of top-script.ps1 script and practical usage of Performance counters on Windows through Powershell. It is intended for people who want Linux top - like tool on Windows.

The script is a part of and available in our existing benchmarking package (dbt2-0.37.50.10) developed by Mikael Ronstrom.

On Top:If you ever did benchmarking on Linux or simply wondered "where did all my resources go", top is your best friend. Since this post is not about Linux, you can google "Linux top explained" for more details.


On Performance counters:To learn about Windows PerfCounters, please refer to my previous …

At Etsy, we have a nice, clean, streamlined build process. We have a command for setting up RAID, and another for OS installation. OS installation comes with automagic for LDAP, Chef roles, etc.

We came across an odd scenario today when a co-worker was building a box that gave the following error:

Traceback (most recent call first): File “/usr/lib/anaconda/storage/partitioning.py”, line 1066, in allocatePartitions disklabel = disklabels[_disk.path] File “/usr/lib/anaconda/storage/partitioning.py”, line 977, in doPartitioning allocatePartitions(storage, disks, partitions, free) File “/usr/lib/anaconda/storage/partitioning.py”, line 274, in doAutoPartition exclusiveDisks=exclusiveDisks) File “/usr/lib/anaconda/dispatch.py”, line 210, in moveStep rc = stepFunc(self.anaconda) File “/usr/lib/anaconda/dispatch.py”, line 126, in gotoNext self.moveStep() File “/usr/lib/anaconda/dispatch.py”, line 233, in …

As Norvald wrote in his recent post:

A long time ago, libmysqlclient came in two versions: one that was thread safe and one that wasn’t. But that was a long time ago. Since MySQL 5.5, the thread safe libmysqlclient_r library has just been a symlink to the libmysqlclient library, which has been thread safe at least since then.

…

I posted earlier in the year how to configure a Fedora instance to test PHP code on a local VM. However, I’ve got a few questions on how to find those posts. Here’s a consolidation with links on those steps:

1. Go to this blog post and install the httpd and php libraries with the yum installer.
2. In the same blog post as step 1 (you can put the sample PHP code into the /var/www/html directory for testing), connect to the yum shell and remove the php-mysql library and then install the mysqlnd library.
3. Go to this blog …