----- Original Message -----
From: "Bill Burke" <bburke(a)redhat.com>
To: "James Livingston" <jlivings(a)redhat.com>
Cc: wildfly-dev(a)lists.jboss.org
Sent: Tuesday, August 5, 2014 7:32:04 AM
Subject: Re: [wildfly-dev] Pooling EJB Session Beans per default
On 8/4/2014 8:44 PM, James Livingston wrote:
> On Mon, 2014-08-04 at 20:22 -0400, Bill Burke wrote:
>> I always liked the ThreadLocal pool. No synchronization, little
>> to no
>> allocations.
>
> It also can cause massive memory leaks if invoked from threads
> which
> aren't re-used, like timer threads, and precautions aren't taken.
> AS/EAP
> 5 suffered from that problem with the default ThreadLocalPool.
>
Which is also something that could be mitigated by a common thread
facility. Something AS/EAP 5 didn't have.
Honestly though, I think this talk of EJB pooling is ridiculous.
Component layers like CDI and JAX-RS don't have pooled architectures
for
their per-request objects. Also, in an average application, there
are
multiple orders of magnitude more non component classes that are
being
instantiated per request. Just think of all the Strings created by a
simple HTTP request.
You want a better focus? How about JSON/XML marshalling? Which
could
make things much easier to maintain then the hand-coded parsers that
Wildfly uses to parse config. And much faster and less memory at
runtime for SOAP and JAX-RS request that currently rely on java
reflection.
You could go research perfect hashing algorithms for URL matching
with
servlets and JAX-RS.
You could go do some perf analysis of all of our frameworks to make
memory reduction and speed recommendations or even Pull Requests.
You could visit each major project and make sure our automated builds
have and can run automated stress tests and are measured against
previous versions.
Or you could just focus on these silly benchmarks that test no-op
HTTP
and EJB requests.
Those silly benchmarks, are indeed silly. Any workload that doesn't actually do
anything with the requests is not very helpful. You can be really fast on them, and be
really slow on a workload that actually does something. We have already seen this in one
case recently.
I also don't like most of the "performance test suites/benchmarks" we have
developed internally. They all suffer from some of the same issues. They don't model
real application interactions and they also tend to have data sizes that are static (like
1KB payloads, or in some cases not within middle-ware, payloads that are as small as 8
bytes!).
Developing benchmarks is not a trivial exercise.
Andy
--
Bill Burke
JBoss, a division of Red Hat
http://bill.burkecentral.com
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