About the Load Balancer in Oracle Java Cloud Service

You can set up a load balancer for your Oracle Java Cloud Service instance, to intercept client requests to the applications deployed on the instance and to distribute the requests to the WebLogic managed servers.

Using a load balancer is recommended if your Oracle Java Cloud Service instance contains more than one WebLogic managed server. You can set up the load balancer to handle encrypting and decrypting TLS traffic, relieving the WebLogic managed servers of the overhead for processing HTTPS requests. You can also suspend access to the applications deployed on your Oracle Java Cloud Service instance, by disabling the load balancer.

Oracle Java Cloud Service supports two load balancer options:
The following are the differences between the load-balancer options:
Feature User-managed (Oracle Traffic Director) Oracle-managed
Creating the load balancer

You can provision the load balancer while creating a service instance, or add the load balancer to an existing service instance.

You can specify the load-balancing policy, the number of load-balancer nodes (one or two), and the compute shape for the nodes.

You can provision the load balancer while creating a service instance, and you can specify the load-balancing policy. You cannot use Oracle Java Cloud Service to add a load balancer to an existing service instance; instead you must manually provision and configure the load balancer.

On Oracle Cloud Infrastructure Classic regions, in order to provision a load balancer, you must also configure the service instance to use Oracle Identity Cloud Service as the identity provider.

Supported load-balancing policies
  • Round robin

  • Least connections

  • Least response time

  • Round robin

  • Least connections

  • IP hash

High availability (HA)

You can create a service instance with two load balancer nodes, or add a second node to an existing service instance. Each node is accessed using a separate IP address.

Note: Oracle Java Cloud Service does not fail-over application requests between load-balancer nodes. If one of the load-balancer nodes is unavailable, you are responsible for ensuring that requests fail over to another node. The failover-group feature of Oracle Traffic Director is not supported.

Oracle Java Cloud Service provisions a load balancer with two nodes that can be accessed using a single IP address.

Network topology

All the Oracle WebLogic Server and Oracle Traffic Director nodes in a service instance are assigned to the same IP network or subnet.

When you create a service instance in an Oracle Cloud Infrastructure region, you can assign a regional subnet that is shared by both load balancer nodes.

You can assign different non-regional subnets to the Oracle WebLogic Server nodes and the Oracle Cloud Infrastructure Load Balancing nodes. The ability to select non-regional subnets in different availability domains is not supported for Oracle WebLogic Server nodes, only for Oracle Cloud Infrastructure Load Balancing nodes. If the selected Oracle Cloud Infrastructure region has only one availability domain, you can only specify one subnet for the load balancer, which is assigned to both load balancer nodes.

You can also create a service instance in which the Oracle WebLogic Server nodes are assigned to a private subnet while the load balancer nodes are assigned to a public subnet. See Create an Oracle Java Cloud Service Instance Attached to a Private Subnet on Oracle Cloud Infrastructure.

Configuring the load balancer You can do the following:
  • Disable and re-enable the load balancer at any time from the Oracle Java Cloud Service interfaces.

  • Add a second load-balancer node, and remove it when it is not required.

  • Connect to the nodes using a secure shell (SSH).

  • Configure the load-balancer settings by using the Oracle Traffic Director administration console.

Note: See the restrictions described in Administration Best Practices.

You can do the following for instances in Oracle Cloud Infrastructure Classic regions:
  • Disable and re-enable the load balancer at any time from the Oracle Java Cloud Service interfaces.

  • Configure the load-balancer settings by using the Oracle Cloud Infrastructure Load Balancing Classic interface.

Patching the nodes

You must patch the Oracle Traffic Director nodes.

Oracle manages the patching of the load balancer.

More information

Features of Oracle Traffic Director in Administering Oracle Traffic Director