We are using the ThreadPoolTaskExecutor within Spring (inside of Tomcat) to launch a concurrent server which listens on a port (3001).
Our code looks a bit like:
....
ServerSocket listener = new ServerSocket(port);
Socket server;
while (true) {
PollingTask pollingTask;
server = listener.accept();
log.info ("Got a new connection, spawning a thread: " + i++);
taskExecutor.execute(new PollingTask(server, i));
}
And the code for PollingTask is similar to:
....
PollingTask(Socket server, int counter) {
this.server = server;
this.counter = counter;
}
public void run() {
input = "";
try {
log.info ("New runnable thread: " + counter);
}
}
....
The Spring configuration looks like:
<bean id="taskExecutor" class="org.springframework.scheduling.concurrent.ThreadPoolTaskExecutor">
<property name="corePoolSize" value="100" />
<property name="maxPoolSize" value="200" />
<property name="queueCapacity" value="50" />
<property name="keepAliveSeconds" value="600" />
</bean>
This particular bean is started on start up, and then we try to connect to the port (3001), using telnet.
Interestingly, we see, in our logs: Got a new connection, spawning a thread: 0 ....
However, it gets all the way to about 48 before it actually shows: New runnable thread: 0 ....
How do I convince Spring to work on the thread / task immediately, rather than waiting?
(I've tried with varying values for queueCapacity)