Category: Server Management

If you’re involved with managing servers, then you’ll already be aware of how little servers offer as far as user interfaces are concerned. Most of the work necessitates the use of the command line interface.

When monitoring servers, you often need to track multiple things simultaneously, such as disk usage, network, CPU temperatures, etc. While all of this information is best presented in a dashboard interface, many creative people have developed makeshift dashboards in the CLI that display information about your system as if you were using a graphical user interface.

By the end of this article, you will be able to use ps, top, htop, and atop, which are some of the most powerful command-line utilities that provide deep insights into system behavior.

Each tool has its strengths, and system administrators often combine them to get a comprehensive view of their systems.

Let’s get started!

The ps Command

The ps command is short for “process status”. It is a fundamental tool in Linux for viewing information about active processes.

The basic syntax for using the ps command is:

ps [options]

When run without any options, ps typically shows:

• The processes associated with the current terminal session
• The process ID (PID)
• The terminal type (TTY)
• The CPU time used
• The command name

Suggested read: Mastering the Echo Command in Linux (with Practical Examples)

Common Options and Flags

The ps command shows useful information, but you can use advanced options and flags to change its default behavior. Here’s a list of some of the possible options:

1. -e or -A: Show all processes
2. -f: Full format listing, providing more details
3. -u username: Show processes for a specific user
4. -p pid: Show information for a specific process ID
5. –sort=[+|-]key: Sort the output. Use + for ascending, – for descending
6. -o format: Customize the output format

Examples of ps Command Usage

The ps command is very flexible. You can mix and match the above flags to produce the desired output. For example:

1. List all processes: ps -e
2. Full format listing of all processes: ps -ef
3. Show processes for a specific user: ps -u username
4. Display processes sorted by CPU usage: ps -eo pid,ppid, cmd,%cpu,%mem --sort=-%cpu
5. Display only the process IDs: ps -eo pid

Suggested read: Pipes vs Xargs: Which One To Use When Writing Bash Scripts In Linux

The top Command

The top command is a real-time system monitoring tool that provides a dynamic, interactive view of a Linux system’s running processes. It displays system summary information and a list of processes or threads currently managed by the Linux kernel.

You can run the top command by executing the following in your terminal:

top

This command launches the top interface, which refreshes by default every 3 seconds.

Understanding the top Interface

The top interface is divided into two main sections presenting different information. Here’s is a quick overview of both sections:

1. Summary Area (top half):
   • System time and uptime
   • Number of users logged in
   • Load average (1, 5, and 15-minute averages)
   • Tasks summary (total, running, sleeping, stopped, zombie)
   • CPU usage breakdown (user, system, idle, etc.)
   • Memory usage (total, free, used, buffers/cache)
   • Swap usage
2. Process List (bottom half):
   • PID: Process ID
   • USER: User who owns the process
   • PR: Priority
   • NI: Nice value
   • VIRT: Virtual memory used
   • RES: Resident memory used
   • SHR: Shared memory
   • S: Process status
   • %CPU: CPU usage
   • %MEM: Memory usage
   • TIME+: Total CPU time
   • COMMAND: Command name

Top Command Flags and Options

The top command also offers various flags and options that allow you to customize its behavior and output. Here are some of the most useful ones:

1. -b (Batch mode): This runs top in batch mode, which is useful for sending output to other programs or a file.
2. -n (Number of iterations): This parameter specifies the number of iterations before the top exits. It is useful in scripts or when capturing a specific number of samples.
3. -p (Monitor specific PIDs): Shows only the processes with the specified PIDs.
4. -u (Show specific user’s processes): Displays only the processes the specified user owns.
5. -H (Show threads): Shows individual threads instead of processes.
6. -o (Sort field): Sorts the process list by a specific field (e.g., CPU usage, memory usage). For example, top -o %CPU
7. –i (Ignore idle processes): Does not display idle or zombie processes.
8. -c (Show command line): Displays the full command line for each process instead of just the command name.
9. -d (Delay time): Sets the delay between updates (in seconds). The default is 3.0 seconds.

These flags can be combined for more specific outputs. For example, the following command will run top in batch mode for five iterations, sorts by memory usage, shows only the root’s processes, and sends the output to a file:

top -b -n 5 -o %MEM -u root > top_output.txt

Remember, you can also interactively use many of these options by pressing the corresponding key while top is running. For instance, pressing ‘h‘ toggles the thread view, ‘i‘ ignores idle processes, and ‘c‘ toggles the command line display.

The htop Command

htop is an interactive process viewer for Unix systems, designed as an enhanced alternative to the top command. It offers several advantages over other process viewers:

1. User-friendly interface: Colorful and more intuitive than top.
2. Mouse support: The mouse can be used to select and interact with the terminal.
3. Tree view: Visualize process relationships.
4. Easier process management: Kill processes without entering their PID.
5. Built-in meters: Includes built-in CPU, memory, and swap usage meters.

Installing htop

htop is typically not pre-installed on most systems. Run the following command with the necessary permissions on your Ubuntu/Debian systems to install it:

sudo apt update && sudo apt install htop

After installation, you can launch htop by simply typing htop in the terminal.

Suggested read: How to Copy Files in Linux and Overwrite without Confirmation

Using htop: interface and navigation

The htop interface is divided into two main sections:

1. Header (top) section shows system-wide stats and meters
   • CPU usage (per-core and overall)
   • Memory usage
   • Swap usage
   • Tasks, load average, uptime
2. Process list (bottom) shows detailed information about each process

The htop interface can be overwhelming at first glance, but once you learn to navigate it, you’ll get detailed information about your system with only a few key presses. Let’s see some keyboard actions and what they do on htop interface:

• Up/Down arrows: Move through the process list
• Left/Right arrows: Scroll horizontally for wide columns
• Space: Tag/untag a process
• U: Untag all processes
• F3 or /: Search for a process
• F4: Filter processes by name
• F5: Tree view
• F6: Sort by column
• F9: Kill a process
• F10 or q: Quit htop

Suggested read: Best 9 htop Alternatives for Linux, Mac & Windows in 2024

Customizing htop display and settings

Like other command line utilities, you can pass some flags to htop to customize its output and display. For example, here is a list of commands with their corresponding effect@

1. htop -t: Start in tree view
2. htop -u username: Show only processes of a specific user
3. htop -p PID1,PID2,...: Show only specified processes

The atop Command

atop (Advanced Top) is a powerful, interactive monitor that allows users to view the load on a Linux system. It shows the status of the most critical hardware resources (CPU, memory, disk, and network) at a system level. It has several unique features that set it apart from other monitoring tools:

1. Persistent logging: atop can write snapshots to a log file for long-term analysis.
2. Resource-specific views: It has dedicated screens for CPU, memory, disk, and network details.
3. Cumulative reporting: It can show resource consumption since the system boot.
4. Process accounting: It can also track short-lived processes that might be missed by interval sampling.

Suggested read: How to Find Most Used Disk Space Directories and Files in Linux

Installing atop

atop is not pre-installed on most systems. You can run the following command to install it on most Ubuntu/Debian distributions:

sudo apt update && sudo apt install atop

After installation, the atop service typically starts automatically for continuous logging.

To view the atop interface, simply type atop in the terminal. This will open up a new screen where you will see the following information:

1. System-level information:
   • Date, time, uptime, and number of systems
   • CPU statistics (user, system, idle, wait, etc.)
   • Memory and swap usage
   • Disk I/O statistics
   • Network statistics
2. Process-level information:
   • PID: Process ID
   • SYSCPU: System CPU time
   • USRCPU: User CPU time
   • VGROW: Virtual memory growth
   • RGROW: Resident memory growth
   • RDDSK: Disk read activity
   • WRDSK: Disk write activity
   • ST: Process state
   • EXC: Exit code
   • CMD: Command name

atop is a powerful tool, and you can enjoy its powers once you learn to navigate it. Here’s a list of some of the basic commands that you can try to get started with atop:

• t: Show detailed system and process statistics for one specific interval
• c, m, d, n: Toggle between CPU, memory, disk, and network-specific views
• v: Show program version info
• z: Show only active processes (hide idle processes)
• 1: Show average-per-CPU utilization
• P, M, D: Sort by CPU, memory, or disk activity, respectively
• q: Quit atop

Suggested read: Introduction to Bash For Loops: A Beginner’s Guide

Final Thoughts: Simplifying System Monitoring with RunCloud

This post has covered some of the most common system monitoring tools for Linux servers. While command-line tools provide powerful and flexible monitoring capabilities, they still require a certain level of expertise to use effectively. Moreover, if you manage multiple servers or want a more user-friendly interface, these tools might not be enough for you.

This is where RunCloud comes into play. RunCloud’s dashboard simplifies server monitoring and management, making it accessible even to those without deep Linux expertise.

Here’s how RunCloud enhances your monitoring experience:

1. Centralized Monitoring: Instead of logging into each server individually, you can monitor all your servers from a single dashboard.
2. User-Friendly Interface: RunCloud presents complex system information in an easy-to-understand graphical interface, eliminating the need to interpret command-line output.
3. Disk Usage Monitoring: Easily track disk usage across all your servers, helping you prevent disk space issues before they become critical.
4. Slow Script Detection: RunCloud can identify slow-running scripts, a feature that typically requires setting up additional monitoring tools on your servers.
5. Alerts and Notifications: Set up custom alerts for various metrics to notify you immediately of any issues.

Ready to simplify your server monitoring and management? Sign up for RunCloud today!

Have you ever found yourself scratching your head, wondering why your buddy can’t access your site while you can access it just fine?

Chances are, your Fail2Ban rules might have blocked them. Don’t worry, we’ve all been there!

In this guide, we’ll explain Fail2Ban and how it works under the hood. This information will help you confidently navigate the server configuration to modify and unban specific IP addresses.

I know what you’re thinking: “Ugh, sounds like a tech nightmare!” But hold your horses! We’re not just going to throw a bunch of command-line gibberish at you. Nope, we’ve got a secret weapon that’ll make managing Fail2Ban as easy as ordering pizza online.

Ready to dive in?

What is Fail2Ban?

Fail2Ban is an open-source intrusion prevention software framework for Linux systems. It monitors system logs and responds to malicious activities by blocking IP addresses. You should note that Fail2Ban alone can’t protect your servers; it is typically used with iptables or similar firewalls to block traffic from banned IP addresses.

Here’s why you should use Fail2Ban on your server:

1. It prevents brute-force attacks
2. It reduces server load from persistent attack attempts
3. It protects multiple services (SSH, web servers, mail servers)
4. It allows for custom rule creation to address specific threats
5. It integrates with existing firewall systems

How Does Fail2Ban Work?

There are several components in a Fail2Ban module that help in protecting your server.

Log Monitoring

Fail2Ban continuously monitors specified log files to identify patterns that indicate potential attacks. Fail2Ban triggers automated responses to mitigate security risks when such patterns are detected.

Furthermore, Fail2Ban runs as a background daemon and consumes minimal system resources, allowing configuration reloading without requiring a full restart. Importantly, Fail2Ban maintains its state across system reboots, ensuring consistent protection even after server restarts.

Jail System

Fail2Ban organizes its rules using a “jail” concept where each jail corresponds to a specific service, such as SSH or Apache. Within these jails, Fail2Ban combines filters and actions. Filters define patterns to detect in system logs, identifying potential threats or malicious behavior.

When triggering a filter, Fail2Ban responds with predefined actions, such as blocking the offending IP address. This modular approach allows Fail2Ban to adapt to various services and efficiently protect against unauthorized access and attacks.

Configuration Structure

Fail2Ban uses a hierarchical configuration system to protect against unauthorized access and attacks efficiently. Let’s see how it works:

1. jail.conf: This is the default configuration file.
2. jail.local: Administrators can override the default settings here to tailor them to their needs.
3. filter.d/*.conf: These files define log parsing rules. They specify patterns to detect in system logs to identify potential threats or malicious behavior.
4. action.d/*.conf: These files specify actions for rule violations. Fail2Ban responds with predefined actions when a filter triggers, such as blocking an offending IP address.

Pattern Matching

Fail2Ban uses regular expressions (regex) for log analysis. This allows it to efficiently identify complex patterns within log files, including IP addresses and timestamps. It also provides customization by supporting user-defined regex for unique log formats.

Beyond static rules, Fail2Ban dynamically adapts to real-time scenarios. You can configure it to lift bans on IP addresses after specified durations automatically. This ensures that legitimate users regain access if they were accidentally blocked. For repeat offenders, Fail2Ban can escalate ban durations to strengthen security measures. Additionally, you can synchronize the list of offending IPs across multiple servers to enhance the overall protection of your network.

How to Unban an IP in Fail2Ban?

Sometimes, you might need to unban an IP address that Fail2Ban has blocked. Here’s how to do it:

Step #1: List all Banned IPs in Fail2Ban

Fail2Ban stores a list of all the IPs currently banned from connecting to your server. Run the following command to see all active jails on your server:

sudo fail2ban-client status

This command shows all active jails. To see banned IPs for a specific jail (e.g., sshd), you can run the following command:

sudo fail2ban-client status sshd

In the above example, don’t forget to replace the sshd with the name of the jail that you want to analyze.

In the above example, you can see the list of all the IP addresses that were banned from connecting to this server. This command can help you identify whether one of your colleagues’ IP addresses was accidentally banned.

Step #2: Unban Specific IP in Fail2Ban

If you find that Fail2Ban banned your IP address, you can either wait for Fail2Ban to unban it or remove it automatically. An offending IP address is banned for 10 minutes by default, but server administrators can extend or reduce this.

However, if you don’t want to wait for the IP address to be automatically removed from the block list, then you can manually log in to your server and run the following command:

sudo fail2ban-client set JAIL unbanip IP_ADDRESS

In the above command, replace JAIL with the specific jail name (e.g., sshd) and IP_ADDRESS with the IP you want to unblock. For example:

sudo fail2ban-client set sshd unbanip 192.168.1.100

The following example shows that the offending IP was found in the block list once. Therefore, the server returned 1 as the output.

This functionality can be handy if you frequently perform security tests on your site that result in your IP address getting banned. This command allows you to continue performing security tests without turning off the firewall or waiting for long periods.

However, there’s an even better way to do this.

Step #3: Whitelist Specific IP in Fail2Ban (optional)

If you have a static IP address or a corporate network where the list of IP ranges is fixed, you can whitelist these IP addresses. Once you add the addresses to the whitelist, these IP addresses will never get blocked, regardless of the number of failed attempts.

However, this can also be a security flaw if misconfigured. We strongly recommend only adding IP addresses belonging to your organization or company. Follow the steps below to prevent Fail2Ban from banning a specific IP in the future:

1. Edit the Fail2Ban configuration file using the following command. If you feel out of your depth here, you can refer to our guide explaining how to edit files on remote servers with SSH and Nano.

sudo nano -l /etc/fail2ban/jail.local

2. After opening the config file, you need to add the list of IP addresses to the ignoreip line. This will tell Fail2Ban to ignore these IP addresses in the future. By default, the 127.0.0.1/8 IP range is automatically whitelisted. If you want to add a specific IP, such as 192.168.1.100 then you can add this IP after it as shown below.

ignoreip = 127.0.0.1/8 ::1 192.168.1.100

1. Once you have added the IP addresses, you can save the file by pressing Ctrl + O, Enter, or Ctrl + X. After saving the file, you need to reload the Fail2Ban service to use the updated configuration. This is slightly faster than restarting the service, as it simply refreshes the configuration without shutting down the application.

sudo systemctl reload fail2ban

After making the changes, checking whether the service is up and running is always a good idea. Run the following command to see if your Fail2Ban service is running smoothly:

systemctl status fail2ban

In the following example, we can see that the service is showing the status of active (running), which means that changing the configuration files didn’t cause any unexpected problems with the Fail2Ban service.

How do you unban IPs in Fail2Ban with RunCloud?

RunCloud provides a user-friendly interface to manage Fail2Ban, making it easier to unban IPs. Here’s how you can do it:

1. Log in to your RunCloud dashboard and navigate to the server where you want to unban an IP.
2. Go to the “Security” tab and switch to the “Fail2Ban” section.
3. On this screen, you’ll see a list of banned IPs.

4. Click the “Delete” button next to the IP you want to unban. If there are too many IPs, you can filter out the IP addresses by using the search functionality.

Final Thoughts

Implementing strict Fail2Ban rules is necessary for protecting your servers from potential threats. A properly configured Fail2Ban instance can help you defend against various attacks. However, it’s essential to recognize that even well-configured systems can sometimes produce false positives, potentially blocking legitimate traffic.

This is why understanding how to unban IP addresses is essential. It lets you quickly restore access for legitimate users who may have been inadvertently blocked, maintaining security and accessibility.

While Fail2Ban is a powerful tool, its complexity can be scary, especially for those new to server management. This is where RunCloud shines.

RunCloud provides a user-friendly interface that simplifies Fail2Ban management, making it accessible to users of all experience levels.

With RunCloud:

• You can easily view and manage banned IPs
• Unbanning becomes a simple, one-click process
• Complex configurations are streamlined through an intuitive interface

This approach is significantly more straightforward than using CLI commands directly on the server. RunCloud’s interface streamlines the entire process, allowing you to focus on your core tasks rather than getting bogged down in server management complexities.

Ready to Simplify Your Server Security?

If you want to enhance your server security without the steep learning curve, RunCloud offers the perfect solution. With its intuitive Fail2Ban integration, you can enjoy robust protection and easy management.

Sign up for RunCloud today and experience user-friendly server management.

FAQs on Fail2Ban

In this post, we’re going to take a look at a vital part of the email system, called the Mail Transfer Agent, sometimes referred to as “mail delivery agent” or even “mail transport agent“. We will discuss what the mail transfer agent is, the advantages of using the mail transfer agent, and finally take a look at some of the best transfer agents for Linux servers.

Did you know that email has been around since 1971, and that currently there are over 8 billion email addresses in the world, used by over 4.5 billion users?

Also, every single second sees over 3.13 million emails sent, which means that since you started reading this article, roughly 8 million emails have landed in people’s inboxes. At least a few of which were actually wanted!

Let’s get started!

What is a Mail Transfer Agent?

An MTA, or Mail Transfer Agent, is a crucial component of the email delivery system that is responsible for transferring emails between the computers of a sender and a recipient. It acts as an intermediary, ensuring that emails reach their intended destinations.

MTA Functions

Acceptance

MTAs are like the receptionists for emails – when you send an email from your Mail User Agent (MUA) such as Gmail or Outlook, the MTA is the first to greet it. It checks if the email is properly formatted, and if the sender and recipient addresses are valid. If everything looks good, the MTA accepts the email and lets it in.

Routing

Once the message is received, MTA directs it to the recipient’s inbox. It looks up the MX records to find out which mail server (destination) the email should go to.

Auto-Responses

If an email fails to reach its destination (maybe the recipient’s server is down), the MTA sends an automatic reply (like saying, “Oops, something went wrong!”) back to the sender.

Queueing

If an email can’t be delivered right away (maybe the recipient’s server is busy), the MTA keeps trying until it successfully delivers the message.

Suggested read: How to Send Email from PHP (With Guided Walkthrough)

Best Linux Mail Transfer Agents (MTAs) You Should Try

When it comes to managing email delivery, choosing the right Linux Mail Transfer Agent (MTA) is crucial. Here are some top-performing MTAs that you should consider, along with their key features:

1. Exim Internet Mailer

Exim is a message transfer agent (MTA) developed at the University of Cambridge for Unix systems connected to the Internet. It operates under the GNU General Public License and offers extensive facilities for checking incoming email.

Although the website looks quite outdated, it is still being actively developed, and you can get the latest updates from its GitHub repository.

It provides a web-based administration and configuration tool for easy management which can be configured as an intermediate mail relay, a mail server for multiple domains, or anything in between.

Exim’s architecture allows for complex configurations and customization as most Linux distributions come with sane default configurations for Exim, making it straightforward to set up.

In addition to supporting basic features such as IMAP server, webmail server, and mail filtering technologies, it also provides the ability to automatically process bounced emails or send emails as faxes.

Suggested read: How to Change/Reset MySQL Root Password on Ubuntu Linux

2. Postfix

Postfix is an email agent designed for Unix systems that aims to be fast, easy to administer, and secure. While its external appearance may resemble Sendmail, its internal architecture is fundamentally different.

Postfix runs on various UNIX platforms, including AIX, BSD, HP-UX, LINUX, MacOS X, Solaris, and Tru64 UNIX. It relies on ANSI C, a POSIX.1 library, and BSD sockets.

While configuring Postfix can be challenging for first time users, its security features and flexibility make it worth exploring. Some of its key features include SMTP client support, configurable DNS filters, and compatibility with various databases (e.g., MongoDB, MySQL, PostgreSQL).

Suggested read: Mastering the Echo Command in Linux (with Practical Examples)

3. Proofpoint

Sendmail, a descendant of the original delivermail program by Eric Allman, is a well-known project within the free and open-source software and Unix communities. It used to be an independent project of its own, but now it is a part of the email protection and thread intelligence suite in Proofpoint.

Sendmail provides a general-purpose email routing facility, and offers a versatile set of delivery methods for sending emails that makes it suitable for large, complex environments.

Sendmail prioritizes security, and its open-source nature allows for community scrutiny and contributions. Additionally, the software releases are signed with PGP keys – which means you can be sure that you’re not running a modified version of the software. It also enables enterprises to plan their messaging infrastructure for the long term, including virtualization, consolidation, and cloud migration.

Suggested read: Using Mailgun To Send Transactional Email From WordPress

4. Axigen

Axigen is an all-in-one email, calendaring, and collaboration platform designed for demanding users, from small businesses to large service providers. The free mail server license includes unrestricted access to new version upgrades, patches, and updates, but technical support is available only for those with commercial versions.

It allows you to gather all your email in one place by retrieving messages from external accounts (e.g., Yahoo! Mail, Gmail) directly into your Axigen inbox. You can also generate temporary email addresses for newsletter subscriptions, or automate administration tasks using the Command Line Interface (CLI) and dedicated APIs.

Team users can grant permissions to other team members to send emails in your name, or define group workflows via public folders – which makes it useful when one colleague is out on a vacation.

Suggested read: How To Speed Up DNS Propagation – The Ultimate Guide

5. Postal

Postal is a comprehensive and fully featured mail delivery platform designed for websites and web servers. It’s open source, and allows you to host your mail server in-house, and configure it as you like.

You can use it to manage mail servers and view mail logs using its easy-to-use web interface, or set up webhooks to receive real-time notifications about message delivery or issues. It supports IP Pools that allow you to send mail from different IP addresses to maintain a good IP reputation.

It also provides a development mode that allows you to automatically hold messages in Postal during testing and development. This is useful if you don’t want to accidentally send out emails to all your customers.

Suggested read: How To Flush DNS Cache — A Full Guide

6. OpenSMTPD

OpenSMTPD is a server-side SMTP protocol implementation, which follows the standards defined by RFC 5321. It enables ordinary machines to exchange emails with other systems using the SMTP protocol. While it lacks frills and is not beginner-friendly, OpenSMTPD offers a fairly complete SMTP solution that is freely usable and reusable under the ISC license.

Despite its somewhat outdated website, OpenSMTPD is actively maintained on its GitHub repository, and unlike feature-heavy alternatives, OpenSMTPD provides a barebones and efficient implementation of a mail transport agent.

Suggested read: How to Copy Files in Linux and Overwrite Without Confirmation

7. Citadel

Citadel is an advanced, multi-user, client/server messaging solution designed for email, collaboration, message boards, content management, and other groupware applications. Whether you’re a small organization or a large-scale public access system, Citadel offers powerful features while remaining easy to install and use.

It is an open-source messaging platform that combines email, collaboration, groupware, and content management. In addition to mailing capabilities, Citadel users can take advantage of a unique “rooms” architecture, bulletin boards (forums), instant messaging, RSS aggregation, and more. You can learn about the additional features offered by Citadel by exploring their documentation.

8. Courier Mail Server

The Courier Mail Server is an integrated mail/groupware server that provides a comprehensive suite of services based on open commodity protocols, including ESMTP, IMAP, POP3, LDAP, SSL, and HTTP. It also offers features such as web-based calendaring, mailing lists, and efficient mail storage using the maildir format.

The Courier mail server can function either as an intermediate mail relay, or perform final delivery to mailboxes. It supports authentication via PAM, LDAP, PostgreSQL, or MySQL, and includes features such as DNS-based blacklists, message filtering, and secure mail delivery channels.

You can use its aggregator proxy which distributes mailboxes across multiple servers, and connects clients to the right server based on the mailbox being accessed.

Wrapping Up

In this post, we have covered different Linux Mail Transfer Agents (MTAs) and how they handle the routing, forwarding, and delivery of emails across networks. We have explored both open source and proprietary tools available for processing emails on a Linux server.

If you are interested in deploying websites as well, then you should definitely check out RunCloud – an all-in-one website management platform.

RunCloud simplifies server management, making it easy for developers, designers, and businesses to deploy websites on the internet. With features such as automated backups, SSL certificate management, and seamless scaling, RunCloud streamlines the process, allowing you to focus on your content and applications.

Ready to take control of your web hosting? Sign up for RunCloud today and experience hassle-free server management! 🚀🌐

FAQs on Mail Transfer Agents (MTAs)

PHP and SQL are two of the most commonly used tools in web development. PHP is a server-side scripting language that is used to create dynamic web pages, while SQL is a database management system that is used to store and retrieve data.

You don’t need to be a Linux expert to manage your servers anymore.

In this article, we will show you how to connect a MySQL database to PHP using the RunCloud dashboard.

We will also discuss two main ways to connect PHP to MariaDB: using mysql_connect and PDO.

Step 1: Create a Database

Before we can start using a database, we need to create a database on the server. We also need to create a user account with permissions to access this database. This can be done easily from the RunCloud dashboard itself.

Open the server on which you want to deploy your application, and click on the “Databases” button in the left menu.

On the next screen, click on “Database Users” and then select “Add New Database User” to create a new user account.

On the next screen, give a descriptive name to the user account and set a password. Be sure to note down these credentials as they will be needed later. Once you have provided the username and password, click “Save” to create the user.

Next, we need to create a database. Click on the “Databases” tab to view all the available databases. To create a fresh database, click on “Add New Database”.

When creating a database you will be asked to provide a name – this can be anything you like. For database collations, you can either leave it blank or refer to our documentation post: Understanding Database Collations.

Finally, from the drop-down menu, select the user account that we created earlier.

Once you have configured these settings, click on “Save”.

Step 2: Connecting to Web Applications

You must deploy a web application on the RunCloud server to run your PHP code. The process to create an application is very simple. In this tutorial we will be creating an empty web application, but the process is similar for any other type of application.

Firstly, go to your web application settings page in the RunCloud dashboard, and scroll down until you see the linked databases section.

Click on the drop-down button, select the database that we just created, and then save the changes.

Next, we will create a PHP file on your server that will host the code to connect to your database.

To do this, click on the File Manager tab in the left menu. Here you will see a list of all the files present in your application.

Click on New > File to create an empty file, and then give it the desired name.

Once you have created the file, click on it. This will open the text editor in a new window where you can edit the file.

Step 3: Coding Database Connection Module

The final step for using a database in your web application is to configure a pre-built library. This will allow you to perform database operations without needing to understand how the database handles these operations. There are two popular ways to do this:

Step 3.1: Use MySQLi

The mysqli connect is a PHP extension used to connect to MySQL databases. It is a simple and easy-to-use method that is ideal for small projects. It is also faster than PDO because it is a native PHP extension. However, it does not support all of the features of PDO.

To use this module, paste the following code snippet in the text editor. Make sure to replace the values of database, username, and password variables with the credentials that you noted down earlier.

<?php
$servername = "127.0.0.1";
$database = "my_app_dv";
$username = "my_db_user";
$password = ".GA8sn,tsP=?5Uy7Lqu#iBy:AzVs3KJE";
// Create connection
$conn = mysqli_connect($servername, $username, $password, $database);
// Check connection
if ($conn->connect_error) {
    die("Connection failed: " . $conn->connect_error);
}
echo "Connected successfully";
mysqli_close($conn);
?>

Step 3.2: Use PDO

PDO is a PHP extension that provides a data-access abstraction layer. PDO also supports multiple database drivers, which makes it more flexible than mysqli connect. However, it is slower than mysqli connect because it is not a native PHP extension.

To use this method, copy the following code example and paste it into your text editor. Don’t forget to update the credentials in the first three lines with the values that you noted down earlier.

<?php
$database = "my_app_dv";
$username = "my_db_user";
$password = ".GA8sn,tsP=?5Uy7Lqu#iBy:AzVs3KJE";
$dsn = "mysql:host=127.0.0.1;dbname=$database;charset=utf8mb4";
$options = [
    PDO::ATTR_EMULATE_PREPARES => false, // Disable emulation mode for "real" prepared statements
    PDO::ATTR_ERRMODE => PDO::ERRMODE_EXCEPTION, // Disable errors in the form of exceptions
    PDO::ATTR_DEFAULT_FETCH_MODE => PDO::FETCH_ASSOC, // Make the default fetch be an associative array
];
try {
    $pdo = new PDO($dsn, $username, $password, $options);
    echo "Connected Successfully";
} catch (Exception $e) {
    error_log($e->getMessage());
    exit("Something bad happened");
}
?>

Step 4: Save and Test Connection

Once you have added the code to your server, click on “Save” to save the changes, and then visit the page in your browser. When you request this page, the server will execute the PHP code and establish a connection to the server.

The exact path of this page will vary depending on what you named the file. For instance, if the domain name of your website is https://www.example.com and you named your file sql.php then you can browse this file at https://www.example.com/sql.php.

If you see a “Connected Successfully” message then it means your code has successfully established a connection with your database, and you can now start using it in your code.

Wrapping Up

In this article, we have seen how to connect a MySQL database to PHP. We have outlined the steps needed for creating a database and granting permissions to user accounts before connecting to the database. We discussed two main ways to connect PHP to MariaDB: using mysqli connect and using PDO – both methods have their own benefits and drawbacks.

If you want to host your web application on the cloud, but aren’t sure where to start, then you should check out RunCloud.

RunCloud is a great platform for managing your servers, even if you are not a Linux expert.

With RunCloud, you can easily create web applications, manage databases, and connect PHP to MariaDB. So, what are you waiting for?

Sign up for RunCloud today and take your server management skills to the next level!

When it comes to monitoring system resources on Linux, htop has been the go-to tool for many administrators and developers alike. Its simple interface and real-time metrics have made it a staple in the toolkit of those who prefer a comprehensive overview of their system’s performance.

You might already know about htop, a great tool for monitoring resource usage on your computer, but it is not the only one out there. In this post, we will show you the best 9 htop alternatives for Linux (including Ubuntu and CentOS), Mac and Windows in 2024.

Let’s get started!

What is htop?

htop is an interactive system-monitoring tool for Unix systems, including Linux. It provides real-time insights into system performance, allowing users to view and manage system processes more efficiently than with the traditional top command. htop displays system metrics such as CPU, memory, swap usage, and process information in a user-friendly, color-coded interface. Users can interact with the tool to perform tasks such as killing processes, renicing tasks, and sorting processes by various criteria.

Unlike the standard top command, htop offers a more dynamic and user-friendly experience. It supports vertical and horizontal scrolling, making it easier to view all processes running on the system, and includes features such as searching for processes, tree view for process hierarchy, and customizable display options. htop is highly customizable and can be configured to suit individual preferences and needs.

Suggested read: How to Copy Files in Linux and Overwrite without Confirmation

3 Best htop Alternatives for Linux

While htop is a powerful tool, there are several alternatives that provide additional features and cater to different use cases. Here are three of the best htop alternatives for Linux:

Glance

Glance is a cross-platform monitoring tool that provides a unified view of system metrics. It is designed to be simple yet comprehensive, displaying essential information about CPU, memory, disk I/O, network interfaces, and processes. Glance is easy to use and provides a web-based interface for remote monitoring.

How to Install Glance

To install Glance, follow these steps:

1. Install Glance: You can use the apt package manager to install Glance on your Linux computer by using the following command:

sudo apt install glances

2. Run Glance: After installing the glance, you can start it by executing the following command:

   glances

In the above example, we can see how the Glances displays an overview of the system resources in the terminal over an SSH connection.

3. Web Interface (Optional): If you want to access the same information over a web interface, then you can start the Glance with the -w parameter, this will start a web server where you can see your resource usage.

   glances -w

In the above example, we can see that the server was started on localhost but if you are using a VPS then you will need to configure your firewall settings to view this interface. Fortunately, this is very simple using the RunCloud dashboard. Just go to the Security tab of your server and add a new rule to open your desired port.

In the above example, the Glances daemon was running on port 61208, once you have configured your firewall, you can access the same dashboard in your web browser by entering the IP address of your server followed by : symbol and the port number as shown below.

Suggested read: Mastering the Echo Command in Linux (with Practical Examples)

atop

atop is an advanced system and process monitor that provides detailed information about system resources. It is particularly useful for performance analysis and troubleshooting as it logs system activity and can show resource usage by individual processes over time. On Ubuntu, you can install and run atop with the following command:

sudo apt-get install atop
sudo atop

In the above example, we can see the system metrics and resource usage on the server using atop dashboard. To enable logging, you can configure atop to run as a daemon by editing the configuration file located at /etc/default/atop and set LOGINTERVAL to a desired value (e.g., 600 for 10-minute intervals).

Suggested read: What are Linux Logs? What Are They & How To Use Them

nmon

nmon (Nigel’s Monitor) is a system performance monitoring tool originally developed for AIX and later ported to Linux. It provides a comprehensive overview of system performance, including CPU, memory, disk I/O, network, and filesystem statistics. nmon is known for its lightweight design and efficiency, making it suitable for real-time monitoring and historical performance analysis.

To install nmon, first make sure that your package manager list is up to date, after that you can execute the following commands to download an run it:

sudo apt-get install nmon
nmon

Once running, you can use various keyboard shortcuts to view different metrics. For example, press c to view CPU usage, m for memory usage, and d for disk statistics.

These alternatives to htop offer a range of features that can be tailored to specific monitoring needs, providing powerful tools for system administrators and users alike.

Suggested read: How to Create and Manage Cron Jobs on Linux

3 Best htop Alternatives for Mac

Mac users often require robust system monitoring tools to keep track of their system’s performance and resources. While htop is a popular choice, several other tools offer similar and additional functionalities tailored to macOS. Here are three of the best htop alternatives for Mac:

iStat Menus

iStat Menus is a comprehensive system monitoring tool that integrates seamlessly with macOS. It provides real-time data on CPU usage, memory, disks, network activity, and other system metrics directly from the menu bar. iStat Menus is highly customizable, allowing users to choose which information to display and how to display it.

How to Install iStat Menus

1. Download: Visit the official iStat Menus website iStat Menus and download the latest version.
2. Install: Open the downloaded .dmg file and drag the iStat Menus icon to your Applications folder.
3. Launch: Open iStat Menus from your Applications folder and follow the setup instructions.
4. Customize: Configure the tool to display the metrics you need from the menu bar.

Activity Monitor

Activity Monitor is the built-in macOS application that provides detailed information about the processes running on your Mac, as well as overall system resource usage. It offers insights into CPU, memory, energy, disk, and network usage, making it a powerful tool for everyday system monitoring.

How to Access Activity Monitor

1. Open Finder: Click on the Finder icon in your dock.
2. Navigate to Applications: Go to the Applications folder and then the Utilities folder.
3. Launch Activity Monitor: Double-click on Activity Monitor to open it.
4. Usage: Use the tabs to monitor CPU, memory, energy, disk, and network activity.

mactop

Latest Apple laptops use Apple silicone which was built using Arm architecture, this means that a lot of the software built for x86 chips is not compatible with latest Apple laptops. mactop is one of the few softwares which was specially built for Apple silicone and it is guaranteed to work with all the M1, M2, and M3 series chips.

You can download and compile the source code from its GitHub repository or simply download and install a pre-built binary directly using brew by using the following command:

brew install mactop

Once it is installed, you can start using it via the following command:

sudo mactop

3 Best htop Equivalent Alternatives for Windows

Windows users looking for powerful system monitoring tools similar to htop on Unix systems have several good options available. These tools provide detailed insights into system performance, process management, and resource usage, making them indispensable for advanced users and system administrators. Here are three of the best htop equivalent alternatives for Windows:

Sysinternals Suite

Sysinternals Suite is a collection of tools from Microsoft which provides detailed information about the processes running on your system, including the handles and DLLs that processes have opened or loaded. It offers a comprehensive overview of system activity, making it an essential tool for troubleshooting and performance monitoring.

How to Install Process Explorer

1. Download Sysinternals Suite: You can either visit the Sysinternals Suite page to download the entire suite or manually download individual tools from SysInternals Live website.
2. Extract the Files: After downloading the file, you can extract the downloaded ZIP file to a desired location.
3. Launch Process Explorer: Navigate to the extracted folder and double-click on procexp.exe to launch Process Explorer. This will open a new window where you can explore different processes running on your computer.

4. Launch Process Monitor: In addition to process explorer, you can also launch the procmon.exe file to run the Process Monitoring tool. Once you have opened the tool, you can browse and manage different processes running on your system and forcefully terminate them if necessary.

Suggested read: How To Check Disk Space in Linux

Windows Task Manager

Windows Task Manager is a built-in system monitoring tool that provides real-time information on CPU, memory, disk, and network usage, as well as detailed process management. It is a powerful utility for basic and intermediate system monitoring and troubleshooting which can be used by anyone without needing to install any additional software.

How to Access Windows Task Manager

1. Open Task Manager: On your Windows computer, press Ctrl + Shift + Esc or right-click on the taskbar and select “Task Manager”.
2. View Processes: In the “Processes” tab, view the list of running applications and background processes along with their CPU, memory, disk, and network usage.

3. Performance Tab: Click on the “Performance” tab to see an overview of system resources such as GPU, CPU, Memory, Network, and Disk.

4. Details and Services: If you want granular control over services, then you switch to the “Details” and “Services” tabs for more advanced process management and service control.

btop++

btop++ is an advanced system resource monitor that works on Windows, providing a detailed and visually appealing interface similar to htop. It offers insights into CPU, memory, disk I/O, and network usage, making it a versatile tool for system performance monitoring.

How to Install btop++

1. Download: Visit the btop++ GitHub repository (also available for Linux) and download the latest release for Windows.
2. Extract the Files: Extract the downloaded ZIP file to a desired location.
3. Install Required Dependencies: Ensure you have Microsoft Visual C++ Redistributable installed, if not, download and install it from the official Microsoft website.
4. Launch btop++: Navigate to the extracted folder and double-click on btop.exe to launch btop++.
5. Usage: After installing it, you can use the interface to monitor system performance metrics and manage processes.

Wrapping Up

Monitoring system performance is crucial for maintaining optimal functionality and troubleshooting potential issues on your Windows, Mac, or Linux systems. While hTop is known to users for its comprehensive and interactive interface, there are powerful alternatives available across different platforms.

Recently, RunCloud has announced the addition of RunCloud Monitoring, a powerful tool designed to identify high resource usage and slow SQL queries on your server. This feature helps ensure that your servers are running smoothly and efficiently, saving you time and reducing the potential for downtime.

Whether you are managing a server or using a personal computer, having the right monitoring tools at your disposal is essential. Sign up for RunCloud today and take advantage of our comprehensive server management and monitoring solutions to keep your systems in top shape.