Scaling the Liferay Service

Liferay Cloud’s auto-scaling feature automatically creates and destroys Liferay service instances as needed to optimize performance. You can choose the minimum and maximum number of instances that can be up at any time. Setting a minimum addresses sudden changes such as increased server traffic, memory leaks, or other issues. Setting a maximum prevents Liferay Cloud from creating instances beyond the maximum you’ve configured. This lowers cost, but risks performance issues. By default, auto-scaling is disabled in every Liferay Cloud account.

Using auto-scaling, a service can increase (upscale) the number of Liferay DXP instances automatically to a defined maximum, or decrease (downscale) to the number specified in the scale property in LCP.json. The scale property specifies the minimum number of instances to run (in addition to the base instance):

   "scale": 2,

Monitor your application’s resource usage (CPU and memory) regularly for applications that require auto-scaling. More insight into your resource requirements helps you more effectively fine-tune your JVM memory settings and auto-scaling behavior.

How Scaling is Charged

Auto-scaling is only available for the Liferay DXP service in production environments. Once it’s enabled, each extra instance of the service incurs an hourly charge. This charge is independent of the normal Liferay PaaS subscription process.

At the end of every quarter that you use or deploy additional instances, Liferay sends you an invoice. You must pay this invoice in accordance with your agreement with Liferay.

For each service instance added via auto-scaling, the price depends on your subscription plan. The total charge is based on the number of clock hours that you used the scaled instances. For pricing purposes, the total usage during a calendar quarter is rounded up to the nearest full clock hour.

Managing Scaling

Follow these steps to enable or disable auto-scaling in the Liferay Cloud Console:

1. Navigate to the production environment.
2. Navigate to Services → Liferay → Scale.
3. Toggle the switch to enable or disable auto-scaling.
4. Choose the minimum and maximum number of extra instances to be created.

Warning

Deleting and redeploying a service disables auto-scaling if it was previously enabled. However, removing auto-scaling properties from a service’s LCP.json file (such as the scale or autoscale properties) from a service does not disable auto-scaling.

With auto-scaling enabled, Liferay Cloud monitors your service and scales it automatically according to the threshold you define.

Setting the Minimum Number of Additional Instances

For scaling to work properly, it is important to set an appropriate memory allocation for your Liferay image’s JVM. This allocation is necessary to allow the memory usage to expand or contract depending on the server’s load.

Set the liferay service’s LIFERAY_JVM_OPTS environment variable to allocate memory using the -Xms and -Xmx flags. The -Xms flag sets the initial memory allocation when the service starts, while the -Xmx flag determines the maximum memory allocation for the JVM. For example, if you have a total of 16 GB provisioned and available for this service, you can set this configuration:

-Xms4096m -Xmx12288m

The recommended configuration is to set the -Xms flag using 25% of the available memory, and to set the -Xmx flag using 75% of the available memory. Always set your -Xmx value lower than the service’s total available memory to avoid errors when other processes in the container require more memory.

Here are some recommended configurations for different levels of memory available to your liferay service:

Available Memory	Recommended LIFERAY_JAVA_OPTS
8 GB	-Xms2048m -Xmx6144m
16 GB	-Xms4096m -Xmx12288m
24 GB	-Xms6144m -Xmx18432m
32 GB	-Xms8192m -Xmx24576m
64 GB	-Xms16384m -Xmx49152m

Note

The LIFERAY_JAVA_OPTS variable may appear with other flags, in addition to -Xms and -Xmx. If other flags are present, update the environment variable with the memory arguments without removing the others.

See Defining Environment Variables for help adding this environment variable to your liferay service.

Setting the Maximum Number of Additional Instances

To define the maximum number of additional instances,

1. Set the LCP_HAPROXY_SERVER_TEMPLATE_BACKEND_NUM environment variable in your web server service to the highest total number needed. The liferay service may not scale beyond the maximum number of instances defined in LCP_HAPROXY_SERVER_TEMPLATE_BACKEND_NUM (10 by default). The maximum possible number is 50 instances (1 base instance and 49 additional instances).

2. On the Liferay service’s Scale tab, update the number in Maximum instances to the desired value.

   Note

   This field sets the additional number of instances that auto-scaling can create, adding to the base number of instances. It does not set the maximum total number it can create.

3. Click Update.

Once you have updated both of these configurations, auto-scaling adds additional instances to the liferay service, up to your newly defined maximum.

Specifying Target Average Utilization

System administrators can specify a target average utilization. This value is an average of memory and CPU usage across Liferay DXP services. That value threshold must be crossed before auto-scaling is triggered.

For example, if three service instances utilize 70%, 90%, and 95% of memory, respectively, then the average memory utilization is 85%. If the target average utilization is set to 90, no upscaling is needed; upscaling in this situation only occurs when the average memory utilization exceeds the target.

Note

The default target utilization is 80%. Services that use a high amount of memory (such as the liferay service) can surpass this target utilization value quickly, even immediately after deployment.

A service downscales only when the service’s memory usage has dropped below half of the target utilization value. With a default target utilization of 80%, a service only reduces the number of instances once the average memory utilization between the available instances drops below 40%.

The total available memory is specified by the memory property in LCP.json, as referenced in Configuration via LCP.json.

Specify the target average utilization in the autoscale property of the service’s LCP.json:

"autoscale": {
  "cpu": 80,
  "memory": 90
}

Balance your target average utilization according to your application’s specific needs for the most efficient auto-scaling. For example, this configuration heavily prioritizes CPU usage:

"autoscale": {
  "cpu": 60,
  "memory": 95
}

If the autoscale property isn’t set, the target average utilization defaults to 80 for both CPU and memory utilization.

Scaling and DXP Activation Keys

An activation key is typically required to be deployed and validated to use self-hosted Liferay DXP. On Liferay Cloud when scaling is enabled, the Liferay Cloud team resolves any DXP Activation key issues and adds and removes activation keys as needed.

Monitoring Scaling

The Plan and Usage page contains the project’s scaling information. Navigate to the Scaling tab. Under Scaling Summary, you can see

• How many environments have extra nodes from scaling
• How many hours scaled nodes were up during the selected time period
• The associated cost in USD for the nodes

Note

The page only displays scaling events that finished before it loaded. Events that have started but haven’t returned to the normal values don’t appear on the page until they finish.

You can also see a detailed report for the selected time period in Scaling Report.