A Technical I.T./DevOps Blog
Problem scenario
You created your own Docker image. You want to upload it to a repository so it is available to other servers. You want to upload a Docker image from your server into ECR (in AWS). You do not know the name of the repository. How do you do this?
Solution
Prerequisites
a. This assumes that ECR has been set up. If you need assistance,
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Continue reading “How Do You Upload a Docker Image to Amazon Elastic Container Registry?”
Problem scenario
You run “sudo npm” or “sudo node” and you get “command not found” error messages. What should you do?
Solution
Modify the /etc/sudoers file. Find the stanza with secure_path. Append “:/usr/local/bin” (with no quotes) to the line.
Here is an example of how the stanza should look (it is often on line 80 of /etc/sudoers):
Defaults secure_path = /sbin:/bin:/usr/sbin:/usr/bin:/usr/local/bin
Once the /etc/sudoers file has been saved,
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Continue reading “How Do You Use “sudo npm” or “sudo node” Commands?”
Problem scenario
You want to find out what version of sudo is on your Linux server. What do you do?
Solution
Run this command:
man sudo | grep Sudo | awk ‘{print $2}’
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Continue reading “How Do You Find What Version of sudo You Are Using?”
Problem scenario
You want to see what servers are in your HDFS cluster (e.g., the DataNodes and the NameNodes). What command can display the FQDNs of such servers?
Solution
Run this command from the NameNode:
hdfs dfsadmin -report | grep Hostname
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Continue reading “How Do You List the Hostnames of the Nodes in Your HDFS Cluster?”
Problem scenario
You installed Jira 7.x on RHEL 7.x in AWS. You try to go to the URL to finish installing and configuring it, but the web UI does not load. On the back-end you see that there is a service listening on port 8080 (with a sudo netstat -anlp | grep 8080 command). You know that now AWS Security Group is blocking port 8080 from the external IP address of the server.
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Continue reading “After Installing Jira on a RHEL Server, How Do You Access the Web UI for Jira?”
Problem scenario
How do you install Jira on any distribution of Linux (e.g., CentOS/RHEL/Fedora, Debian/Ubuntu, or SUSE)?
Prerequisite
Do you have 3 GB of RAM? 1 GB of RAM will work, but you only if you have 2 GB of virtual memory. (With 1 GB of RAM or less and no virtual memory on the server, the installation will fail. The catalina.out log will report an error about insufficient memory.)
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Continue reading “How Do You Install Jira on a Linux Server?”
Problem scenario
You are trying to install Jira on Linux. You log into the web UI to finish configuration. The process stalls at this stage:
” Finishing your setup
Now sit back while we set up your JIRA instance. It will take a minute or two to complete.
Configuring your database
Initializing the plugin system – Don’t worry, I’m still working…”
On the back-end you may notice the server’s load average gets above 5.
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Problem scenario
You have a Linux server (a Debian/Ubuntu, CentOS/RedHat/Fedora or SUSE distribution). You want to install Apache Avro. What do you do?
Solution
These directions work for any type of Linux.
#1 Do one of the following (either option A or option B).
Option A
Find the latest download from here and download it.
Option B
cd /tmp
curl http://mirror.metrocast.net/apache/avro/avro-1.8.2/avro-src-1.8.2.tar.gz >
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Problem scenario
You find that your Jira is very slow and sometimes stalls or hangs when it is being used. The Linux back-end of the Jira server shows considerable CPU and memory constraints. When Jira is up on the back end you use the Linux “top” command, you find that the CPU and RAM are being heavily utilized. You want to optimize the system for improved performance.
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Continue reading “What Can Be Done to Enhance the Reliability and Performance of a Jira Server?”
Problem scenario
You created a DB instance in RDS. You cannot connect to it. What should you do?
Solution
1. Make sure that it is “Available.” It could have been turned off.
2. Click on the Instance and confirm the relevant Security Group allows you to connect to it.
3. Click on the Instance and search for “Publicly accessible”. Make sure this is set to “Yes.” If it is set to “No” you may have to take a snapshot of the instance and launch that snapshot with the “Publicly accessible” option.
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Continue reading “How Do You Troubleshoot Connecting to an RDS Instance?”