Knowledgebase

Seesaw is an open-source, high-availability (HA) load balancer designed for use in cloud environments and data centers. It offers robust features for creating redundant, high-availability load balancing solutions for applications and services. Seesaw is commonly used for IP failover, service routing, and ensuring high availability for critical services.

In this tutorial, we will walk you through the steps of installing and configuring Seesaw on your AnonVM server to provide high availability and load balancing capabilities.

Table of Contents

1. Prerequisites
2. What is Seesaw?
3. Installing Seesaw on AnonVM
4. Basic Seesaw Configuration
5. Configuring Seesaw for High Availability
6. Configuring Seesaw with Backend Servers
7. Securing Seesaw with SSL (Optional)
8. Troubleshooting Seesaw

1. Prerequisites

Before proceeding with the installation, ensure that you have the following:

• Operating System: A supported Linux distribution, such as Ubuntu or CentOS.
• Root or Sudo Access: You need root privileges to install software and configure Seesaw.
• Internet Access: Seesaw requires internet access to install dependencies and packages.
• Multiple Servers for High Availability: To use Seesaw for high availability, you should have at least two backend servers for load balancing.

2. What is Seesaw?

Seesaw is a high-availability (HA) load balancer that can be used to ensure your services or applications remain online even if one of your backend servers goes down. It's particularly useful in a distributed environment where uptime is critical. Seesaw works by utilizing a virtual IP (VIP) that automatically fails over to a backup server if the primary server fails.

Some of the key features of Seesaw include:

• IP Failover: Seamless failover between multiple backend servers.
• Load Balancing: Distributes traffic efficiently across multiple servers.
• Health Checks: Monitors the health of backend services and ensures traffic is routed to healthy servers.
• High Availability: Provides redundancy to ensure services remain online even during server failures.

3. Installing Seesaw on AnonVM

Step 1: Update Your System

Start by updating your system to ensure all packages are up to date.

Step 2: Install Dependencies

Seesaw requires a few dependencies to be installed. These dependencies include iptables, iproute2, and keepalived. Install them using the following commands:

Step 3: Download and Install Seesaw

Currently, Seesaw is available from the GitHub repository. You can download and install Seesaw as follows:

1. Clone the Seesaw Repository:

    

   git clone https://github.com/google/seesaw.git cd seesaw

2. Build Seesaw:

   Seesaw requires Go to build from the source. If you don't have Go installed, you can install it first:

    

   sudo apt install golang -y

   Once Go is installed, run the following commands to build Seesaw:

    

   go build

   This will build the Seesaw binaries.

Step 4: Configure Seesaw

After building Seesaw, you need to configure it for your environment. The configuration is done through a configuration file that defines the backend servers, health checks, and other settings.

1. Create a Seesaw Configuration File:

   Create the directory for the configuration file:

    

   sudo mkdir /etc/seesaw sudo nano /etc/seesaw/seesaw.conf

   Add the following basic configuration:

   ini

    

   [global] vip = 192.168.1.100 # Virtual IP address iface = eth0 # Network interface to use mode = active-backup # High Availability mode

2. Configure Backend Servers:

   In the same configuration file, you can define the backend servers that will be load balanced by Seesaw.

   ini

    

   [backends] server1 = 192.168.1.10 server2 = 192.168.1.11

   Replace server1 and server2 with the IP addresses of your backend servers.

4. Basic Seesaw Configuration

Now that Seesaw is installed and the basic configuration is in place, you can start it by running the following command:

This will start Seesaw and enable the load balancing functionality.

5. Configuring Seesaw for High Availability

Seesaw works by setting up two or more servers in a high-availability configuration. One server is active and the others are in standby mode. In case the active server fails, traffic is automatically routed to one of the standby servers.

1. Configure Keepalived:

   Seesaw requires keepalived to manage the virtual IP and ensure failover. Edit the keepalived.conf file on both servers:

    

   sudo nano /etc/keepalived/keepalived.conf

   Add the following configuration for each server:

   For the primary server (active):

   ini

    

   vrrp_instance VI_1 { state MASTER interface eth0 virtual_router_id 51 priority 101 advert_int 1 virtual_ipaddress { 192.168.1.100 # Virtual IP address } }

   For the secondary server (standby):

   ini

    

   vrrp_instance VI_1 { state BACKUP interface eth0 virtual_router_id 51 priority 100 advert_int 1 virtual_ipaddress { 192.168.1.100 # Virtual IP address } }

2. Start Keepalived:

   After configuring keepalived, start it on both servers:

    

   sudo systemctl start keepalived sudo systemctl enable keepalived

6. Configuring Seesaw with Backend Servers

Once Seesaw is running, you can configure it to route traffic to the backend servers. You can add more servers as needed, and Seesaw will distribute traffic among them.

1. Edit the Backend Configuration:

   Open the Seesaw configuration file (/etc/seesaw/seesaw.conf) and add additional backend servers as necessary.

   Example:

   ini

    

   [backends] server1 = 192.168.1.10 server2 = 192.168.1.11 server3 = 192.168.1.12 # New backend server

2. Reload Seesaw:

   After adding the new backend server, reload Seesaw to apply the changes:

    

   sudo ./seesaw reload

7. Securing Seesaw with SSL (Optional)

To secure traffic between clients and your backend servers, you can configure Seesaw to use SSL. This can be done using a self-signed certificate or an SSL certificate from a trusted Certificate Authority.

1. Obtain or Generate SSL Certificates.

   You can use tools like Let's Encrypt to generate SSL certificates for your domain.

2. Configure SSL in Seesaw:

   In your Seesaw configuration file, add the paths to your SSL certificate and key:

   ini

    

   [ssl] cert = /etc/ssl/certs/seesaw.crt key = /etc/ssl/private/seesaw.key

3. Restart Seesaw:

   After configuring SSL, restart Seesaw to apply the changes:

    

   sudo ./seesaw restart

8. Troubleshooting Seesaw

If you encounter issues, here are some steps to troubleshoot:

• Check Seesaw Logs:

   

  sudo tail -f /var/log/seesaw.log

• Verify Network Configuration: Ensure that the virtual IP address is correctly configured and that all servers can communicate with each other.

• Verify Keepalived: Ensure that keepalived is running correctly on all servers.

Conclusion

With Seesaw installed and configured, you now have a robust high-availability solution for load balancing your web services across multiple backend servers. Whether you're hosting critical applications or managing cloud-based services, Seesaw ensures high availability and seamless traffic distribution.