Package software.amazon.awssdk.core.client.config

Class SdkAdvancedAsyncClientOption<T>

java.lang.Object

software.amazon.awssdk.utils.AttributeMap.Key<T>

software.amazon.awssdk.core.client.config.ClientOption<T>

software.amazon.awssdk.core.client.config.SdkAdvancedAsyncClientOption<T>

Type Parameters:

T - The type of value associated with the option.

public final class SdkAdvancedAsyncClientOption<T>
extends ClientOption<T>

A collection of advanced options that can be configured on an async AWS client via ClientAsyncConfiguration.Builder.advancedOption(SdkAdvancedAsyncClientOption, Object).

These options are usually not required outside of testing or advanced libraries, so most users should not need to configure them.

Nested Class Summary

Nested classes/interfaces inherited from class software.amazon.awssdk.utils.AttributeMap.Key

AttributeMap.Key.UnsafeValueType

Field Summary

Fields

Modifier and Type	Field	Description
static SdkAdvancedAsyncClientOption<Executor>	FUTURE_COMPLETION_EXECUTOR	Configure the Executor that should be used to complete the CompletableFuture that is returned by the async service client.

Method Summary

Methods inherited from class software.amazon.awssdk.utils.AttributeMap.Key

convertValue, toString

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Field Detail

FUTURE_COMPLETION_EXECUTOR

public static final SdkAdvancedAsyncClientOption<Executor> FUTURE_COMPLETION_EXECUTOR

Configure the Executor that should be used to complete the CompletableFuture that is returned by the async service client. By default, this is a dedicated, per-client ThreadPoolExecutor that is managed by the SDK.

The configured Executor will be invoked by the async HTTP client's I/O threads (e.g., EventLoops), which must be reserved for non-blocking behavior. Blocking an I/O thread can cause severe performance degradation, including across multiple clients, as clients are configured, by default, to share a single I/O thread pool (e.g., EventLoopGroup).

You should typically only want to customize the future-completion Executor for a few possible reasons:

1. You want more fine-grained control over the ThreadPoolExecutor used, such as configuring the pool size or sharing a single pool between multiple clients.
2. You want to add instrumentation (i.e., metrics) around how the Executor is used.
3. You know, for certain, that all of your CompletableFuture usage is strictly non-blocking, and you wish to remove the minor overhead incurred by using a separate thread. In this case, you can use Runnable::run to execute the future-completion directly from within the I/O thread.