In the absence of an
Executor bean in the context, Spring Boot auto-configures a
ThreadPoolTaskExecutor with sensible defaults that can be automatically associated to asynchronous task execution (
@EnableAsync) and Spring MVC asynchronous request processing.
If you have defined a custom
The thread pool uses 8 core threads that can grow and shrink according to the load.
Those default settings can be fine-tuned using the
spring.task.execution namespace as shown in the following example:
spring.task.execution.pool.max-size=16 spring.task.execution.pool.queue-capacity=100 spring.task.execution.pool.keep-alive=10s
This changes the thread pool to use a bounded queue so that when the queue is full (100 tasks), the thread pool increases to maximum 16 threads. Shrinking of the pool is more aggressive as threads are reclaimed when they are idle for 10 seconds (rather than 60 seconds by default).
ThreadPoolTaskScheduler can also be auto-configured if need to be associated to scheduled task execution (
The thread pool uses one thread by default and those settings can be fine-tuned using the
TaskExecutorBuilder bean and a
TaskSchedulerBuilder bean are made available in the context if a custom executor or scheduler needs to be created.