A Technical I.T./DevOps Blog
Problem scenario
You created a Linux VM in GCP. How do you get credentials to connect to it? What do you have to do to log in with PuTTY?
Solution
1. Make sure the firewalls allow for the connection. See this posting if you need to change that.
2. In the GCP console, go to Computer Engine -VM Instances.
3.
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Continue reading “How Do You Log into a Linux Server in Google Cloud Platform?”
Problem scenario
You have a RedHat Enterprise version of Linux. You want to install the R programming language. What do you do?
Solution
1. Run these six commands:
sudo yum -y install wget
cd /tmp
wget ftp://rpmfind.net/linux/epel/7/x86_64/e/epel-release-7-10.noarch.rpm
sudo rpm -ivh epel-release-7-10.noarch.rpm
sudo yum-config-manager –enable rhui-REGION-rhel-server-extras rhui-REGION-rhel-server-optional
sudo yum -y install R
2. This is an optional step to complete these instructions.
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Continue reading “How Do You Install R on a RHEL Instance of AWS?”
Problem scenario
You want to install Scala to a Red Hat Enterprise Linux instance of AWS. How do you do this?
Solution
1. Install Java: sudo yum -y install java-1.8*
2. Log off and log back on.
3. Run these three commands:
curl https://bintray.com/sbt/rpm/rpm | sudo tee /etc/yum.repos.d/bintray-sbt-rpm.repo
sudo yum -y install sbt
sbt new scala/hello-world.g8
4.
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Continue reading “How Do You Install Scala on a RHEL Instance of AWS?”
Problem scenario
You run this command:
javac -version
But you receive this error: “Error occurred during initialization of VM java.lang.Error: Properties init: Could not determine current working directory.”
How do you solve this problem?
Solution
Log out of Linux and log back in.
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Problem scenario
You are looking for the Hadoop components’ versions. You run these commands:
hadoop version
hdfs version
yarn version
You notice the output is the same for each of the three commands above. You are not sure if Apache Spark has been installed. What do you do?
Solution
Run this command:
spark-submit –version
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Continue reading “How Do You Know If Apache Spark Has Been Installed?”
Problem scenario
You want to try Sikulix to test it. What do you do to implement a prototype of GUI automation of a basic procedure?
Solution
Prerequisite #1
This assumes that Sikulix has been installed. If you do not know how, see this posting.
Prerequisite #2 (specific to this example only)
For this example we will set up an automation to open a web browser,
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Problem scenario
You want to determine which version of R is installed. How do you find this out in Linux?
Solution
Run this command:
R –version
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Continue reading “How Do You Know What Version of R Is Installed on Your Linux System?”
Problem scenario
You have recently deployed Apache Spark to AWS. You see the EC-2 instances were created. But you cannot access them over the web UI (even over ports 4140, 8088, or 50070). You cannot access the instances via Putty. You changed your normal Security Group to allow TCP communication from your work station’s IP address. What should you do to connect to your new Spark instance for the first time?
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Continue reading “How Do You Connect to Your Apache Spark Deployment in AWS?”
Problem scenario
You want to deploy Apache Spark to AWS. How do you do this?
Solution
1. Log into the AWS management console. Once in, go to this link.
2. Click “Create cluster” and then “Quick Create”
3. For Software Configuration, choose “Spark:…”
4. For “Security and access”, for EC2 key pair, choose the key pair you desire.
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Continue reading “How Do You Deploy an Apache Spark Cluster in AWS?”
Problem scenario
You want to change the password at the SQL level — not with the OS — of the user named Postgres in your PostgreSQL install. How do you change this password?
Solution
1. Enter the SQL database to run a DDL command.
2. Run this command to change the user named “postgres” to the password “abcd1234” with no quotes:
ALTER USER “postgres” WITH PASSWORD ‘abcd1234’;
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