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Re: [jetty-users] maxQueued

I'll start with the JMX part of the question first.

Looks like the maxQueued attribute is not exposed.
That's a bug, filed an issue against it ->

As for the rest of the question...
We had too many issues with ArrayBlockingQueue, we removed support for maxQueued and the ArrayBlockingQueue from QueuedThreadPool starting in Jetty 9.
It started out as a performance question, then part of our mechanical sympathy efforts.

Eventually, some performance tests were run ...

And we determined that the ArrayBlockingQueue performs some harsh JDK locking that actually hurts performance.
So we removed it as part of our Queue/ThreadPool cleanup

However, we also made Jetty 9 use the built-in java.util.concurrent techniques.
Which allowed us to even expose that entire framework as an option for developers to use as the ThreadPool for jetty.

The wiki about high load doesn't mention the maxQueued configuration for QueuedThreadPool, as that's not related to high load in our minds.
It would be like trying to improve the performance of an F1 racer by changing the length of the spark plug wires.

Joakim Erdfelt <joakim@xxxxxxxxxxx>
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On Tue, Nov 19, 2013 at 6:22 PM, Chris Berry <cberry@xxxxxxxxxxxx> wrote:

I want to use maxQueued in the <server> config.
And I'm pretty certain I have it setup properly in my jetty.xml
(Note: I DO see my other settings confirmed in the JMX MBean)

<Configure id="Server" class="org.eclipse.jetty.server.Server">
    <Set name="ThreadPool">      <New class="org.eclipse.jetty.util.thread.QueuedThreadPool">        <Set name="name">Jetty</Set>
        <Set name="maxQueued"><Property name="jetty.maxQueued" default="-1"/></Set>
        <Set name="minThreads"><Property name="jetty.minThreads" default="10"/></Set>
        <Set name="maxThreads"><Property name="jetty.maxThreads" default="200"/></Set>
        <Set name="detailedDump">false</Set>

I read the source code, and as far as I can tell, by defining "maxQueued" I should get an ArrayBlockingQueue created.
But see no way to confirm that I actually got this right.

When I look at JMX, I see no mention of "maxQueued" -- whether I define it or not.

BTW: this doc:  makes no mention of "maxQueued".
This seems odd, as "maxQueued" is a more concise method to accomplish this.

But even when I try the method in that doc — by defining the ArrayBlockingQueue directly.
I still see no mention of "maxQueued" in the JMX

So my questions.
  1. Is there something wrong with my XML?
  2. How can I check my work here and confirm that I am in fact using an ArrayBlockingQueue?
  3. Why doesn't the JMX MBean (org.eclipse.jetty.util.thread:type=queuedthreadpool,id=0)  expose "maxQueued"? 
Thanks very much,
-- Chris 

I am using Jetty 7.6.5.v20120716

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