Clustering#

Gluu Gateway is based on the Kong Gateway, which supports clustering. Kong's docs about clustering are available here.

A Kong cluster can scale the system horizontally by adding more machines/VMs/containers to handle more incoming requests.

To configure multiple Kong nodes into a cluster, point them all to the same datastore or use the same declarative configuration in DB-less mode.

A load balancer is required in front of the Kong cluster to distribute traffic across the available nodes.

Architecture#

GG has some more components for full integration, Kong, GG UI, OXD-server and Gluu Server.

There are two approaches in Kong for configuration storage.

GG Kong DB Clustering#

In this approach Kong uses the Database(Postgres or Cassandra) to store the Services, Routes, Plugins and Consumer.

You can see in below diagram it using Kong Database for storing configuration and same database access by every Kong Node.

GG Kong DB-less Clustering#

In this approach Kong uses the second configuration file, in YAML or JSON, using declarative configuration.

To use Kong in DB-less mode, set the database directive of kong.conf to off. As usual, you can do this by editing kong.conf and setting database=off or via environment variables. You can then start Kong as usual.

Check here for Kong DB-less configurations.

In below diagram there is no Kong Database. It use YAML Configuration file on every node with same configurations.

Components and configurations#

Kong Node

You need to install Kong on every Node. Which will share the same Database and Configurations.
OXD-Server

Kong(Plugins) uses the OXD-Server for every operation to communicate with OP Server. For OXD-Server clustering you need to deploy OXD-Server on every node and use the same redis for central data storage and access. For more details check OXD redis setup docs.
GG UI

You need only one UI to configure Kong. In DB-Less mode, you only see the configurations. To update the configuration, you need to update the YAML Config file.
Plugins

You can use any kong approach to store the configurations. In diagrams there is one rate-limiting plugin example. Which point to same redis server for data store, accsss and share between all the kong nodes.

Set up the Gluu Gateway node#

Before Setup Nodes, You need to install the GG one any one node so you have GG UI, Postgres DB and OXD Server. which you can connect to other nodes for quick setup.

Below are the 2 steps to setup the kong nodes.

1. Install Kong#

Ubuntu 16

Download Kong 2.0.1 from here.

sudo apt-get update
sudo apt-get install openssl libpcre3 procps perl
sudo dpkg -i kong-*.deb

Ubuntu 18

Download Kong 2.0.1 from here.

sudo apt-get update
sudo apt-get install openssl libpcre3 procps perl
sudo dpkg -i kong-*.deb

RHEL 7

Download Kong 2.0.1 from here

sudo yum install kong-*.rpm --nogpgcheck

CentOS 7

Download Kong 2.0.1 from here

sudo yum install epel-release
sudo yum install kong-*.rpm --nogpgcheck

2. Set up GG plugins and libraries#

Download gluu-gateway-node-deps.tar.gz
tar -xvzf gluu-gateway-node-deps.tar.gz
cd gluu-gateway-node-deps
python gg-kong-node-setup.py

The script will ask the following questions about the Postgres database, which is shared between the nodes. If you want to configure DB-less then after this setup, you need to manually update the kong.conf.

Questions	Descriptions
Enter PG host	Enter your Postgres database host or IP
Enter PG Port	Enter your Postgres database port
Enter PG User	Enter your Postgres database user
Enter PG Password	Enter your Postgres database password. It will not show during typing values, so you just need to type your password.
Enter PG Database	Enter your Postgres database name which you are already sharing between multiple kong nodes.

Done. If any problems arise, check the gg-kong-setup-error.log and gg-kong-setup.log log files.

Other Kong configurations are adjusted by updating /etc/kong/kong.conf.