A Technical I.T./DevOps Blog
Problem scenario
You want to copy files between RedHat Linux servers with adherence to security best practices. You try to use scp but you get “Permission denied.” What do you do to copy files in a secure way?
Solution
1. Verify you can SSH from one server to the other. For directions for setting up SSH in a cross-cloud environment, you may want to see this posting.
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Continue reading “How Do You Use scp When You Get A “Permission Denied” Error?”
Problem scenario
When trying to install Apache Parquet on Ubuntu, you get this error:
Running python-snappy-0.5.1/setup.py -q bdist_egg –dist-dir /tmp/easy_install-SIHL_T/python-snappy-0.5.1/egg-dist-tmp-O8UnkU
WARNING: ‘.’ not a valid package name; please use only .-separated package names in setup.py
package init file ‘__init__.py’ not found (or not a regular file)
cc1plus: warning: command line option ‘-Wstrict-prototypes’ is valid for C/ObjC but not for C++
snappymodule.cc:31:22: fatal error: snappy-c.h: No such file or directory
compilation terminated.
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Problem scenario
You have a web page from an .php file that includes HTML code. There are fields visible in the web page to the user. These fields accept text. You want the fields to not be blank; you want the fields to have suggested values of text in them. You want the data in the fields to be taken from the result of a SQL statement. How do you prepopulate text fields in a LAPP web page with values from SQL statements?
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Continue reading “How Do You Prepopulate Text Fields in a Web Page with Values from a SQL Database?”
Problem scenario
You want to use Maven’s Apache Parquet plugin with Hadoop. How do you use these Apache technologies together?
Solution
1. Install HDFS. See this link if you are using Ubuntu. See this link if you are using a RedHat distribution of Linux. If you have more than one server and want a multi-node cluster of Hadoop, see this link for directions on how to deploy and configure it.
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Continue reading “How Do You Configure Maven to Use an Apache Parquet Plugin?”
Problem Scenario
You are logged into the web UI of HipChat. You expect to hover over either your name or the question mark icon in the upper right hand corner and see drop down options. But this is not what happens. When you single-click on your name or the question mark icon, you briefly get a glimpse of menu options. You want to click on the menu options. How do you do this?
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Continue reading “How Do You Get to See Settings and The Help Menu of Atlassian HipChat?”
Various companies such as Google use Linux desktops instead of Windows (according to ZDNet). According to TechReublic other big names that use it are NASA, the French military police, CERN (which is also known as the European Organization for Nuclear Research) and the U.S. Department of Defense. While an estimated 1.5% of desktops use Linux, it is a good choice for staying safe from viruses and spyware.
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Continue reading “Roughly 1.5% of Workstations Run Linux and Linux vs. Windows at the Workplace”
Problem scenario
In Windows you sometimes watch DVDs but have to stop the movie mid-way through. You cannot always watch an entire movie in one setting from start-to-finish. You stop the DVD by closing Windows Media Player while the movie was still playing or paused. Later after you have shut off your computer, you want to resume the DVD at the exact hour,
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Continue reading “How Do You Resume a DVD Movie Where You Stopped Watching It?”
Problem scenario
You want to learn more about low latency programming for working at a hedge fund company. Where do you begin?
Solution
An Amazon search for “low latency programming” brings up books that could be very useful for other high-paying I.T. jobs in big data such as an Apache Thrift book or a book for Building a Columnar Database on RAMCloud.
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Continue reading “How Do You Learn More About “Low Latency Programming”?”
Problem scenario
You are running Linux SUSE in AWS. You want to have no firewalls running on the OS. How can you be sure that there is no OS-level firewall running in Linux SUSE?
Solution
#1 Become root with this command: sudo su –
#2 Enter this command: yast firewall
#3 You will see either a screen that warns you about another firewall running or you’ll see the YaST2 screen for a firewall.
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Continue reading “How Do You Turn off OS Firewalls in an AWS Instance of Linux SUSE?”
Problem scenario
Let’s say you want to rearrange the columns a of SQL table because a special order would make subsequent SQL commands easier. Or you just want to avoid disk contention on the underlying storage device. How do you optimize SQL to do less input/output activity on the disk while being able to rearrange the order of columns?
Solution
There are other ways such as avoiding “select *”,
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