Skip to main content

Limiting Bitrate and Network Throttling

We may limit incoming or outcoming data rates to/from our infrastructure to maintain the stability of our service for customers. Bitrate limitation is an action to limit the number of bits that can be passed through a transmission channel in a period of time. Network throttling is an intentional action to slow down transmission speed in a network channel. It is not only about limiting bitrate but also limiting the allowed number of requests in a period of time. There are several tools and techniques that can be used to apply bitrate limitation and network throttling.


Wondershaper

It is an easy-to-use tool for Linux and is already in the package repository. It can limit the bit rate that can be achieved by network interfaces in the system. We can install it by running the following command.

apt install wondershaper

We can choose an interface to have a limitation either or both on download and upload.

wondershaper <interface-name> <download-rate-in-bps> <upload-rate-in-bps>

For example, the following code will limit eth0 to 40k bits/s of download rate and 20k bits/s of upload rate.

wondershaper eth0 40000 20000

To clear the setting, we can run the following command.

wondershaper clear eth0

Trickle

Based on its manual page, Trickle is a tool to limit the download or upload rate of any applications that utilize the socket interface. We can read more information about this tool here. We need to remember that only programs with dynamic linking can work with Trickle. We can test whether a binary can work with Trickle by the following command.

ldd $(which [binary]) | grep libc.so
For example,
ldd $(which wget) | grep libc.so

If it shows the location of libc.so, it means the binary can work with Trickle. For instance, if we want to limit the download rate of the wget tool, we can use the following example.

trickle -d [rate in KB/s] wget [protocol://file-URL] 

Nginx

Nginx is actually a proxy server that provides plenty of features to help us serve our web-based services such as the request rate and bandwidth limiting capability. This feature is used to prevent DDoS attacks by preventing our server to handle too many requests. It needs a defined key to differentiate a client from another, a memory zone to keep states of all the keys, and a rate-setting that states the number of requests per second or minute. The examples are as follows.

http {
    #...
    limit_req_zone $binary_remote_addr zone=one:10m rate=1r/s;

    server {
        #...
        location /search/ {
            limit_req zone=one;
        }
        location /search2/ {
        	# if request rate > specified rate, 5 requests are queued
            limit_req zone=one burst=5; 
        }
        location /search3/ {
        	# 5 excessive requests are served immediately
            limit_req zone=one burst=5 nodelay; 
        }
        location /search4/ {
        	# 3 excessive requests are served immediately, 2 requests are delayed
            limit_req zone=one burst=5 delay=3; 
        }
    }
}

Bandwidth limiting is applied per connection while Nginx originally allows multiple connections. It means if we want the exact bitrate value to be provided for specific addresses, we can set Nginx to allow only one connection.

http {
    limit_conn_zone $binary_remote_address zone=addr:10m;
    
    # mapping for dynamic configuration
    map $ssl_protocol $response_rate {
      "TLSv1.1" 10k;
      "TLSv1.2" 100k;
      "TLSv1.3" 1000k;
    }

    server {
        root /www/data;
        limit_conn addr 5;

        location /download/ {
            limit_conn       addr 1;
            # rate limiting is applied after 1MB data is passed
            limit_rate_after 1m; 
            limit_rate       50k;
        }
        
        # dynamic configuration
        location /secure/ {
            limit_rate       $response_rate;
        }
    }
}

We can get more information from Nginx documentation.


Comments

Popular posts from this blog

Configuring Swap Memory on Ubuntu Using Ansible

If we maintain a Linux machine with a low memory capacity while we are required to run an application with high memory consumption, enabling swap memory is an option. Ansible can be utilized as a helper tool to automate the creation of swap memory. A swap file can be allocated in the available storage of the machine. The swap file then can be assigned as a swap memory. Firstly, we should prepare the inventory file. The following snippet is an example, you must provide your own configuration. [server] 192.168.1.2 [server:vars] ansible_user=root ansible_ssh_private_key_file=~/.ssh/id_rsa Secondly, we need to prepare the task file that contains not only the tasks but also some variables and connection information. For instance, we set /swapfile  as the name of our swap file. We also set the swap memory size to 2GB and the swappiness level to 60. - hosts: server become: true vars: swap_vars: size: 2G swappiness: 60 For simplicity, we only check the...

Rangkaian Sensor Infrared dengan Photo Dioda

Keunggulan photodioda dibandingkan LDR adalah photodioda lebih tidak rentan terhadap noise karena hanya menerima sinar infrared, sedangkan LDR menerima seluruh cahaya yang ada termasuk infrared. Rangkaian yang akan kita gunakan adalah seperti gambar di bawah ini. Pada saat intensitas Infrared yang diterima Photodiode besar maka tahanan Photodiode menjadi kecil, sedangkan jika intensitas Infrared yang diterima Photodiode kecil maka tahanan yang dimiliki photodiode besar. Jika  tahanan photodiode kecil  maka tegangan  V- akan kecil . Misal tahanan photodiode mengecil menjadi 10kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 10 / (10+10) x Vcc V- = (1/2) x 5 Volt V- = 2.5 Volt Sedangkan jika  tahanan photodiode besar  maka tegangan  V- akan besar  (mendekati nilai Vcc). Misal tahanan photodiode menjadi 150kOhm. Maka dengan teorema pembagi tegangan: V- = Rrx/(Rrx + R2) x Vcc V- = 150 / (1...

Deploying a Web Server on UpCloud using Terraform Modules

In my earlier post , I shared an example of deploying UpCloud infrastructure using Terraform from scratch. In this post, I want to share how to deploy the infrastructure using available Terraform modules to speed up the set-up process, especially for common use cases like preparing a web server. For instance, our need is to deploy a website with some conditions as follows. The website can be accessed through HTTPS. If the request is HTTP, it will be redirected to HTTPS. There are 2 domains, web1.yourdomain.com and web2.yourdomain.com . But, users should be redirected to "web2" if they are visiting "web1". There are 4 main modules that we need to set up the environment. Private network. It allows the load balancer to connect with the server and pass the traffic. Server. It is used to host the website. Load balancer. It includes backend and frontend configuration. Dynamic certificate. It is requ...

Configure Gitlab SMTP Setting

Gitlab CE or EE is shipped with the capability to send messages through SMTP service as the basic feature to send notifications or updates to the users. The configuration parameters are available in /etc/gitlab/gitlab.rb . Each SMTP service provider has a different configuration, therefore the Gitlab configuration parameters should be adjusted according to the requirements. Some examples have been provided by Gitlab here . This is an example if you use the Zoho service. gitlab_rails['smtp_enable'] = true gitlab_rails['smtp_address'] = "smtp.zoho.com" gitlab_rails['smtp_port'] = 587 gitlab_rails['smtp_authentication'] = "plain" gitlab_rails['smtp_enable_starttls_auto'] = true gitlab_rails['smtp_user_name'] = "gitlab@mydomain.com" gitlab_rails['smtp_password'] = "mypassword" gitlab_rails['smtp_domain'] = "smtp.zoho.com" This is another example of using Amazon SES w...

API Gateway Using KrakenD

The increasing demands of users for high-quality web services create the need to integrate various technologies into our application. This will cause the code base to grow larger, making maintenance more difficult over time. A microservices approach offers a solution, where the application is built by combining multiple smaller services, each with a distinct function. For example, one service handles authentication, another manages business functions, another maintains file uploads, and so on. These services communicate and integrate through a common channel. On the client side, users don't need to understand how the application is built or how it functions internally. They simply send a request to a single endpoint, and processes like authentication, caching, or database querying happen seamlessly. This is where an API gateway is effective. It handles user requests and directs them to the appropriate handler. There are several tools available for building an API gateway, su...

Running CI/CD Pipeline with GitLab CI

GitLab allows us to deploy CI/CD pipeline runners on our own resources within our environment. This option is available not only for the self-hosted plan but also for the cloud service plan (gitlab.com). With this setup, unlike GitHub Action, we can avoid incurring additional costs for extended pipeline runtime. This is because we can deploy the runner on an on-demand server and optimize its usage. GitLab CI offers several options for setting up resources to run CI/CD pipelines. A runner can be configured to handle jobs for specific groups or projects using designated tags. It can also be set to use different executors, such as Shell, Docker, Kubernetes, or VirtualBox. A comparison table of the supported executors is available in the executor documentation . Some executors offer greater flexibility and ease of use, while others may be more rigid but enhance server security. Installing the runner in our machine For example, we will deploy the runner on an Ubuntu serve...