Anypoint Flex Gateway — How to Configure Multiple Replicas

Published in

Another Integration Blog

4 min readMay 26, 2023

In my previous articles I have explained about what flex gateway is and how to setup flex gateway in local & connected mode; for more details about my previous articles please refer below links.
In this article I am going to explain about how to configure replicas in the flex gateway.
How to Setup Anypoint Flex Gateway | by Venkatesh Jujarao | Another Integration Blog | Medium
Flex Gateway Setup — Local Mode. This article is an extension of my… | by Venkatesh Jujarao | Another Integration Blog | May, 2023 | Medium

Prerequisite

Flex Gateway with single replica.
To understand how to do that please refer flex local and connected mode article.

Configure the Replicas (Linux Server)

Assumption is that we have already configured flex gateway with single replica with connected mode.

Locate the registration.yaml file (available under conf.d folder ).

Install WinScp and copy the file to the local.

If you can’t install WinScp then copy the content of file from putty only (open the file in vi editor and copy the content).

Now spin-up the new Linux instance and once its ready follow below steps -

Install Flex Gateway

A new Linux instance doesn’t have the flex gateway, so we need to install the flex gateway first.

Before Install — No Conf.d folder available

sudo tee /etc/yum.repos.d/flex-gateway.repo <<\EOF
[flex-gateway]
name = Anypoint Flex Gateway
baseurl = https://flex-packages.anypoint.mulesoft.com/amazonlinux/$releasever/main
gpgcheck = 1
gpgkey = https://flex-packages.anypoint.mulesoft.com/amazonlinux/pubkey.gpg
repo_gpgcheck = 1
enabled = 1
EOF
sudo yum install -y flex-gateway

Now we can see the conf.d folder is available in the new Linux instance.

Now, add the registration.yaml file taken from previous Linux instance to new Linux instance under conf.d folder.

Start Flex Gateway

Once we have installed the flex gateway and copied the registration.yaml file then let’s start the flex gateway.

sudo systemctl start flex-gateway

Check the status.

systemctl list-units flex-gateway*

Check Replicas Status on Runtime Manager

Go to Runtime Manager → Flex Gateway → Name Of your Flex Gateway (in this case demoflxgateway)

Now here we can see multiple replicas has been configured.

Now, let’s deploy the application and see how the traffics are getting routed to these replicas. Refer one of my flex gateway local and connected mode article to understand how to deploy the application.

Verify Traffic is Routing to Multiple Instances

Now we have created the replicas, but we need to understand how the traffic will get routed to both replicas so that traffic will be distributed equally, performance will be improved and api would be highly available.

Create a Load Balancer

When replicas are configured without any load balancer then client has to write logic from their end to load balance their request accordingly as shown below, which is not an ideal approach.

Mutiple Replicas — Client Calling each time different URL.

To avoid this, we need to add a load balancer in front of our replicas so that client need not have to worry about different replicas URL, and they will just make a call to single URL and internally Load Balancer will take care of routing and distributing the load to respective replica URL; as shown in below diagram.

Below article will help you to create your own application load balancer in AWS
Guide to Create Elastic Load Balancer in AWS | by Venkatesh Jujarao | May, 2023 | Medium