Thread Pools Tuning
GridGain creates and maintains a variety of thread pools that are used for different purposes. In this section, we list some of the more common internal pools and show how you can create a custom one.
System Pool
The system pool handles all the cache related operations except for SQL and some other types of queries that go to the queries pool. Also, this pool is responsible for processing compute tasks' cancellation operations.
The default pool size is max(8, total number of cores).
Use IgniteConfiguration.setSystemThreadPoolSize(…) or a similar API from your programming language to change the pool size.
Queries Pool
The queries pool takes care of all SQL, Scan, and SPI queries being sent and executed across the cluster.
The default pool size is max(8, total number of cores).
Use IgniteConfiguration.setQueryThreadPoolSize(…) or a similar API from your programming language to change the pool size.
Public Pool
Public pool is the work-horse of the Compute Grid. All computations are received and processed by this pool.
The default pool size is max(8, total number of cores). Use IgniteConfiguration.setPublicThreadPoolSize(…) or a similar API from your programming language to change the pool size.
Service Pool
Service Grid calls go to the services' thread pool. Having dedicated pools for the Service and Compute components allows us to avoid threads starvation and deadlocks when a service implementation wants to call a computation or vice versa.
The default pool size is max(8, total number of cores). Use IgniteConfiguration.setServiceThreadPoolSize(…) or a similar API from your programming language to change the pool size.
Striped Pool
The striped pool helps accelerate basic cache operations and transactions by spreading operations execution across multiple stripes that don’t contend with each other for resources.
The default pool size is max(8, total number of cores). Use IgniteConfiguration.setStripedPoolSize(…) or a similar API from your programming language to change the pool size.
Data Streamer Pool
The data streamer pool processes all messages and requests coming from IgniteDataStreamer and a variety of streaming adapters that use IgniteDataStreamer internally.
The default pool size is max(8, total number of cores). Use IgniteConfiguration.setDataStreamerThreadPoolSize(…) or a similar API from your programming language to change the pool size.
Creating Custom Thread Pool
It is possible to configure a custom thread pool for compute tasks. This is useful if you want to execute one compute task from another synchronously avoiding deadlocks. To guarantee this, you need to make sure that a nested task is executed in a thread pool separate from the parent’s tasks thread pool.
A custom pool is defined in IgniteConfiguration and must have a unique name:
<bean class="org.apache.ignite.configuration.IgniteConfiguration">
<property name="executorConfiguration">
<list>
<bean class="org.apache.ignite.configuration.ExecutorConfiguration">
<property name="name" value="myPool"/>
<property name="size" value="16"/>
</bean>
</list>
</property>
</bean>IgniteConfiguration cfg = new IgniteConfiguration();
cfg.setExecutorConfiguration(new ExecutorConfiguration("myPool").setSize(16));Now, let’s assume that you want to execute the following compute task in a thread from the myPool defined above:
public class InnerRunnable implements IgniteRunnable {
@Override
public void run() {
System.out.println("Hello from inner runnable!");
}
}To do that, use IgniteCompute.withExecutor(), which will execute the task immediately from the parent task, as shown below:
public class OuterRunnable implements IgniteRunnable {
@IgniteInstanceResource
private Ignite ignite;
@Override
public void run() {
// Synchronously execute InnerRunnable in a custom executor.
ignite.compute().withExecutor("myPool").run(new InnerRunnable());
System.out.println("outer runnable is executed");
}
}The parent task’s execution might be triggered the following way and, in this scenario, it will be executed by the public pool:
ignite.compute().run(new OuterRunnable());© 2024 GridGain Systems, Inc. All Rights Reserved. Privacy Policy | Legal Notices. GridGain® is a registered trademark of GridGain Systems, Inc.
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