Configuring Caching to Improve Performance

Repeatedly getting the same information from the server is time-consuming and expensive. Therefore, you can improve the performance of WSO2 IoT Server by configuring the following caching scenarios:

Device caching configurations

Performance improves when device cache is enabled as the server doesn't have to make several request calls to get the device information such as device ID, device name, and more. Once the device cache expires, the server gets the information again when the next request call goes out and stores it until it expires again.

To improve performance, you can enable the device cache for all the worker nodes in a clustered setup.

Open the <IOTS_HOME>/conf/cdm-config.xml file and configure the following:
The default configuration is as follows:

<DeviceCacheConfiguration>
	<Enable>true</Enable>
	<ExpiryTime>600</ExpiryTime>
</DeviceCacheConfiguration>

Property Description

Enable

By default, the device caching is enabled. If you don't want to have it enabled you can define false as the value but this will affect the performance of WSO2 IoT Server after enrolling many devices.

ExpireTime

The time the cache needs expire. Define the time in seconds.

By default, a certificates cache is set to ten minutes, which is 600 seconds. You can define a preferred expiry time period.

Certificate caching configurations

WSO2 IoT Server has a caching layer before the database for mutual SSL certificates. Previously, each time a device sent a request, WSO2 IoT Server authenticated and validated the mutual SSL certificate against the database. With the new approach, the server doesn't have to go to the database to gather the certificate details each time a request is made and this improves the performance.

Let's look at how you can configure it:

Open the <IOTS_HOME>/conf/cdm-config.xml file and configure the following:
The default configuration is as follows:

<CertificateCacheConfiguration>
	<Enable>true</Enable>
	<ExpiryTime>86400</ExpiryTime>
</CertificateCacheConfiguration>

Property Description

Enable

By default, the certificate caching is set true.

If you don't want to have it enabled you can define false as the value but this will affect the performance of WSO2 IoT Server when having many certificates.

ExpireTime

The time the certificate cache should expire. Define the time in seconds.

By default, a certificates cache is set to one day, which is 86400 seconds. Since the certificate expiry time is longer you can set a higher value, such as one month or more if you have few devices enrolled with WSO2 IoT Server. If your server has many enrolled devices, make sure to set the value for at least 2 to 3 days and not more than that as it will lead to out of memory issues with caching.

Policy caching configurations

This section is work in progress!

WSO2 IoT Server has a caching layer for the device policies. <Info to come in>

Let's look at how you can configure it:

Open the <IOTS_HOME>/conf/cdm-config.xml file and configure the following:
The default configuration is as follows:

<PolicyConfiguration>
	<CacheEnable>true</CacheEnable>
</PolicyConfiguration>

Property Description

CacheEnable

By default, the policy caching is set true.

If you don't want to have it enabled you can define false as the value but this will affect the performance of WSO2 IoT Server when you have many device policies.