Showing posts from June, 2021

Digital Marketing

“I hope this email finds you well” is a generic email greeting that has been carried over from obsolete business letters.

It is aimed at conveying an act of well-wishing to the email recipient.

Turn Gmail dynamic email on or off

On your computer, sign in to Gmail. At the top right, select Settings Settingsand then See all settings. Next to "Dynamic email," turn on or off Enable dynamic email. At the bottom of the page, click Save changes. Tip: You can identify dynamic email when you see a lightning bolt next to a message.

Open Journal of Veterinary Medicine (OJVM)

Open Journal of Veterinary Medicine (OJVM) is an international journal dedicated to the latest advancement of Veterinary Medicine. The goal of this journal is to provide a platform for scientists and academicians all over the world to promote, share, and discuss various new issues and developments in different areas of Veterinary Medicine.

Database Embedded JVM (OJVM)

OJVM is the Oracle Java Virtual Machine which gives you the ability to execute JAVA code directly in the database. OJVM is the Oracle Java Virtual Machine which gives you the ability to execute JAVA code directly in the database. Embedded JVM (OJVM) The embedded JVM runs Java code in user session (within the dedicated or shared server), in the same memory space as SQL and PL/SQL. These Java modules can be invoked by any database client, similarly to PL/SQL modules. 

Block a Domain in Outlook Mail on the Web

Select Settings (the gear icon ⚙️). Select View all Outlook settings. Select Mail > Junk email. In the Blocked senders and domains section, select Add. Type the domain name you want to block, then press Enter to add the domain to the list. ... Select Save, then close the Settings dialog box.

How To Configure a AWS EC2 Service to Start Automatically

sudo chkconfig service_name on sudo chkconfig service_name off sudo chkconfig service_name status

How to install fail2ban on AWS EC2

    sudo yum update && sudo yum install epel-release     sudo yum install fail2ban     sudo systemctl start fail2ban     sudo service fail2ban start     sudo chkconfig  fail2ban on

mysqlbinlog - Utility for Processing Binary Log Files for MySQL

MySQL server's binary log consists of files containing “events” that describe modifications to database contents. The server writes these files in binary format. To display their contents in text format, use the mysqlbinlog utility. You can also use mysqlbinlog to display the contents of relay log files written by a slave server in a replication setup because relay logs have the same format as binary logs. Example usage: mysqlbinlog mysql-bin.000212 --start-position=589388355 | mysql   --login-path=db5 mysqlbinlog binlog.0000088 --start-datetime="2015-08-08 18:08:08" | mysql --login-path=db5 --force

How to calculate sum size of files

 For example, sum size of all MySQL bin log files: $ sudo du -cb /var/lib/mysql/mysql-bin.* | awk 'END{print $1}' 704384831090 option -b will display each file in bytes and -c will print the total size. To calculate a specific date, such as Jul 1st:  $ sudo ls -l /var/lib/mysql/mysql-bin.*  | grep "Jul 1" | awk '{print $9}' | xargs du -cb | awk 'END{print $1}' 605065048493

Check MySQL databases size

 To determine the sizes of all of your databases, at the mysql> prompt type the following command: SELECT table_schema AS "Database", ROUND(SUM(data_length + index_length) / 1024 / 1024, 2) AS "Size (MB)" FROM information_schema.TABLES GROUP BY table_schema; To determine the sizes of all of the tables in a specific database, at the mysql> prompt, type the following command. Replace database_name with the name of the database that you want to check: SELECT table_name AS "Table", ROUND(((data_length + index_length) / 1024 / 1024), 2) AS "Size (MB)" FROM information_schema.TABLES WHERE table_schema = "database_name" ORDER BY (data_length + index_length) DESC;

Show MySQL Users

 Mysql> SELECT user,host FROM mysql.user;

Allowing MySQL Root Access from Specific IP address

GRANT ALL PRIVILEGES ON *.* TO 'root'@'' IDENTIFIED BY 'password' WITH GRANT OPTION; make all your changes to affect. FLUSH PRIVILEGES; You don't need to restart your MySQL server.

PowerMTA pmta command

Usage: pmta [options] command where 'options' are:     --help                display this message     --xml                 display result in XML     --dom                 display result as DOM-like "variables" and where 'command' is one of:     clear dnscache domainname     check mfrom [--tcp] [--dumppackets] mfrom ip     check spf [--tcp] [--dumppackets] ip heloDomain [mailFrom]     delete [--dsn] [--queue=domain[/vmta]] [--orig=addr] [--rcpt=addr] [--jobId=id] [--envId=id] [--older-than=time-interval] [--no-accounting]     deregister [--user=name] [--local-only] [--retain-unloaded]     disable source [--reenable-after=interval] ip domain[/vmta]     enable source ip domain[/vmta]     list [--queue=domain[/vmta]] [--orig=addr] [--rcpt=addr] [--jobId=id] [--envId=id] [--maxitems=n] [--older-than=time-interval] [--pause] [--priority] [--schedule]     pause queue domain[/vmta]     pause job jobid     register [--user=name] [--label=name] [--webmon-ip=ip] [--webm

Virtual MTA is the technology PMTA uses to control IPs and Host to create several virtual gateways with one MTA server.

The VMTA prefix is the value that appends with each VirtualMTA in the config file. 

Fixed WSL sshd: no hostkeys available -- exiting

Encountered:  $  sudo service ssh --full-restart  * Stopping OpenBSD Secure Shell server sshd                                                                     [ OK ]  * Starting OpenBSD Secure Shell server sshd                                                                            sshd: no hostkeys available -- exiting. Run ssh-keygen -A In the /etc/ssh/ folder, and then restart the server by: $  sudo service ssh --full-restart  * Stopping OpenBSD Secure Shell server sshd                                                                     [ OK ]  * Starting OpenBSD Secure Shell server sshd                                                                     [ OK ]

How to fix screen Cannot find terminfo entry for 'screen.xterm-256color'

Switch back to the terminal app that we first set the screen. For example, switch from Gnome Terminal to LXTerminal. Or Find out which TERM is supported: ls /usr/share/terminfo/x This will give you a list of supported TERMs i.e. xterm xterm-xfree86 set the environment variable: export TERM=xterm-xfree86 and run screen: TERMINFO='/usr/share/terminfo/' screen

How to clear Powermta mail queue

Stop powermta first: $ sudo systemctl stop pmta or sudo service pmta stop. Go to powermta mail queue directory: $ cd /var/spool/pmta/ Remove all mails in the queue: $ sudo rm -rf * Restart the powermta: $ sudo systemctl restart pmta or sudo service pmta start. See also: How to delete / clear queue of PowerMTA

How to delete / clear queue of PowerMTA

To delete / clear queue of PowerMTA: Use  pmta delete Syntax : pmta delete  [–dsn] [–queue=domain[/vmta] [–orig=addr] [–rcpt=addr] [–jobId=id] [–envId=id] [–accounting] Description : Deletes recipients from the queue. Although “–queue”‘s default is */*, the command requires either –queue or –jobId to be entered explicitly, so that an accidental “pmta delete” command doesn’t delete the entire queue. Messages are marked in the accounting file as deleted by administrator. Options : –dsn specifies that a DSN report should be sent. Using this option may slow the deletion process. No entry is written to the accounting file unless the –accounting flag is used as well. –accounting specifies that deletion information should be written to the accounting file. Using this option may slow the deletion process. –queue specifies which queue(s) to delete from, and defaults to all queues. –orig specifies that only recipients with the MAIL FROM address be deleted –rcpt specifies that only r

ssh-agent is a key manager for SSH.

ssh-agent holds your keys and certificates in memory, unencrypted, and ready for use by ssh.  ssh-agent saves you from typing a passphrase every time you connect to a server. It runs in the background on your system, separately from ssh, and it usually starts up the first time you run ssh after a reboot. The SSH agent keeps private keys safe because of what it doesn’t do: It doesn’t write any key material to disk. It doesn’t allow your private keys to be exported. Private keys stored in the agent can only be used for one purpose: signing a message.

Run multiple command on a remote host over SSH


Causes ssh to print its configuration after evaluating Host and Match blocks and exit

      -G      Causes ssh to print its configuration after evaluating Host              and Match blocks and exit. Example:  $ ssh -G p | awk '$1 == "hostname" { print $2 }'

Insert key on HP Envy X360

The key that says "ins" is on the 0 button on the 10 key pad. And you have to use the "num lock" to unlock the number to enable your insert key.

Find out which containers use the docker volume

 docker ps -a --filter volume=VOLUME_NAME_OR_MOUNT_POINT

Inbound Jenkins agents communicate with the Jenkins controller through TCP port 50000 by default.

You can change this port number on your Jenkins controller through the Configure Global Security page.

nofail in fstab - continue booting after errors occur

The nofail option helps make sure that the VM starts even if the file system is corrupted or the file system doesn't exist at startup. We recommend that you use the nofail option in the fstab file to enable startup to continue after errors occur in partitions that are not required for the VM to start.

Solution: MySQL/AWS RDS error: “you do not have SUPER privileges…”

  In addition to editing log_bin_trust_function_creators = 1 you need to remove all  DEFINER  from your SQL queries.

The easiest way to create a file is to use the touch command.

 touch my-new-file

To find out more about a Docker image, run docker image inspect a-docker-image-such-as-ubuntu

Cloud Native Computing Foundation Projects

The CNCF is a vendor-neutral home for various open-source projects, including Kubernetes, Prometheus, Envoy, Linkerd, NATS, and more!  Graduated and incubated projects CNCF Landscape .

Serverless computing refers to a new model of cloud native computing, enabled by architectures that do not require server management to build and run applications.

Container orchestration

Kubernetes, Swarm, Nomad, and ECS

Using the docker image history command, you can see the command that was used to create each layer within an image.

If two containers are on the same network, they can talk to each other. If they aren't, they can't.

Separate containers let you version and update versions in isolation

VSCode is a streamlined source-code editor made by Microsoft for Windows, Linux and macOS that’s fine-tuned for building and debugging modern web and cloud applications.

Reset Vim back to square one

Remove everything from your vim configuration remove the entire .vim folder as well as everything from your .vimrc file.  Keep the empty file in place though because without it vim will start in compatible mode by default. (base) [ec2-user@dockers ~]$ rm .vim -rf (base) [ec2-user@dockers ~]$ rm .vimrc (base) [ec2-user@dockers ~]$ touch .vimrc; mkdir .vim

GraalVM is a high-performance polyglot runtime supporting a variety of different languages

GraalVM is a high-performance polyglot runtime supporting a variety of different languages, including JavaScript, Ruby, R, Python, and JVM languages such as Java, Scala or Kotlin.

The GraalVM compiler is a dynamic just-in-time (JIT) compiler, written in Java, that transforms bytecode into machine code.

The GraalVM compiler integrates with the Java HotSpot VM, which supports a compatible version of the JVM Compiler Interface (JVMCI).

Stop cron job service

If you are using Redhat (RHEL)/Fedora Core/Cent OS Linux use the following command : $ sudo systemctl status crond If you are using Debian or Ubuntu Linux the following command : $ sudo systemctl status cron

Run Programs Faster Anywhere - GraalVM

Increase application throughput and reduce latency Compile applications into small self-contained native binaries Seamlessly use multiple languages and libraries