Java Configuration

When your organization uses deployed Transformer for Snowflake engines, you can modify the following Java configuration options in the deployment advanced properties:

To modify these Java configuration options, in Control Hub, edit the deployment. In the Configure Engine section, click Advanced Configuration. Then, click Java Configuration.

When defining Java configuration options, avoid defining duplicate options. If you do define duplicates, the last option passed to the JVM usually takes precedence.

Java Heap Size

Modify the Transformer for Snowflake Java heap size as necessary, based on the resources available. By default, Transformer for Snowflake uses 50 percent of the available memory as the Java heap size. In most cases, the default percentage value is sufficient.

The Java heap size determines the heap size allocated to Transformer for Snowflake and affects the amount of memory Transformer for Snowflake can use when it runs a pipeline. For example, with a heap size of 2048 MB, you can configure a pipeline to use up to 65% - that's 1331 MB of memory.

To modify the Java heap size, first select the JVM memory strategy to use:

Percentage - For a tarball installation, allocates a percentage of the available memory on the host machine as the Java heap size. For a Docker image installation, allocates a percentage of the available memory in the Docker container as the Java heap size.
Absolute - Allocates an absolute number in megabytes as the Java heap size.

Based on your selection, configure the minimum and maximum Java heap size in percentage or in an absolute value in megabytes. To avoid constant recalculation of the allocated heap size, set both the minimum and maximum properties to the same value.

Consider the following guidelines when you define the heap size:

Transformer for Snowflake requires a heap size of at least 1024 MB to run. As a result, the engine always uses a minimum of 1024 MB for the heap size, regardless of the configured size.
By default, Java 11 enables the UseCompressedOops option, which allows a maximum of 32 GB of heap size regardless of the configured size. To allocate more than 32 GB, disable the option by adding the following Java option to the Java Options property in the Java configuration properties:
```
-XX:-UseCompressedOops
```
In the pipeline properties, you can use the jvm:maxMemoryMB() function to help define the percentage of the heap size the pipeline uses.

Remote Debugging

You can enable remote debugging to debug a Transformer for Snowflake instance running on a remote machine.

Enable remote debugging by modifying the Java Options property in the Java configuration properties. Add the following debugging options to the property, where port_number is an open port number on the remote machine running Transformer for Snowflake:

-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=<port_number>,suspend=n

For example, to debug Transformer for Snowflake on a remote machine using port number 2005, define the Java options as follows:

-Xdebug -Xrunjdwp:server=y,transport=dt_socket,address=2005,suspend=n

Garbage Collector

You can define the Java garbage collector that Transformer for Snowflake uses. By default, Java 11 uses the G1 garbage collector.

Define the garbage collector by modifying the Java Options property in the Java configuration properties. If you define another garbage collector, test and evaluate Transformer for Snowflake performance before making the same change in a production environment. Garbage collector performance depends on each particular use case.