Dynamic Proxy Memory Leak

[hendryluk]

We were experiencing a memory leak issue on production, which WinDbg unveals to be a leak on dynamcally generated assemblies. (Thousands of dynamic-assemblies are loaded onto the process before eventually bringing the server down to its knees, causing our Azure instances to reboot).
After we eventually tried to uninstall Glimpse, the issues seem to have been resolved.
Upon examining Glimpse source-code, I narrowed my suspicion down to the Glimpse.MVC3 component. In particular, within the Glimpse.Mvc3.Extensions.ModelBinderExtensions.CreateDynamicProxy(IModelBinder, IGlimpseLogger) method.

internal static IModelBinder CreateDynamicProxy(this IModelBinder modelBinder, IGlimpseLogger logger)
{
    var proxyConfig = new Dictionary<string, IInterceptor>
                          {
                              {"BindModel", new BindModelInterceptor()},
                              {"BindProperty", new BindPropertyInterceptor()},
                              {"CreateModel", new CreateModelInterceptor()},
                          };

    var proxyGenerator = new ProxyGenerator();  // <- code in question
    var proxyGenOptions = new ProxyGenerationOptions(new SimpleProxyGenerationHook(logger, proxyConfig.Keys.ToArray())) { Selector = new SimpleInterceptorSelector(proxyConfig) };
    return (IModelBinder)proxyGenerator.CreateClassProxy(modelBinder.GetType(), proxyGenOptions, proxyConfig.Values.ToArray());
}

The method instantiates a new instance of ProxyGenerator every time, which results in a new dynamic type generated every single time, as opposed to reusing what has been previously generated (as in the case when we reuse the ProxyGenerator instance). Since type/assembly definitions can never be garbage collected in .net, this will result in a memory-leak.
Can this be looked into?
Thanks in advance

[avanderhoorn]

@hendryluk, this information has been a massive help. We are in the process of making some changes around this stuff, so we will make the changes to adjust this at the same time. Thanks again.

[hendryluk]

Cheers @avanderhoorn

[Bunk]

I left the Glimpse code enabled on a production level machine (I know, I know) and noticed that this memory leak will very quickly take down the process and produce Out of Memory exceptions. We only experience about 150 concurrent users on this system at any given time, but at that rate it only takes a couple of hours to balloon the memory up to 2-3 gigs (normal execution is around 200-300Mb).

The leak is mitigated by disabling Glimpse in the web.config.

[avanderhoorn]

Thanks for brining this up. We are pretty sure we know what the issue is
and how to fix it. If you can wait on it we are fixing this along with
several other thing in an upcoming release. If its something you want now
let us know and we can see if we can bring this fix forward.
Cheers
Anthony

On Tuesday, December 13, 2011, Bunk <
reply@reply.github.com>
wrote:

I left the Glimpse code enabled on a production level machine (I know, I
know) and noticed that this memory leak will very quickly take down the
process and produce Out of Memory exceptions. We only experience about 150
concurrent users on this system at any given time, but at that rate it only
takes a couple of hours to balloon the memory up to 2-3 gigs (normal
execution is around 200-300Mb).

The leak is mitigated by disabling Glimpse in the web.config.

---

Reply to this email directly or view it on GitHub:
#126 (comment)

[Bunk]

We currently have this disabled in production so we can wait. Thanks for the quick response!

[avanderhoorn]

Not a problem. Hopefully we will have time to finish things off soon.
Cheers
A

On Tue, Dec 13, 2011 at 7:49 AM, Bunk <
reply@reply.github.com

wrote:

We currently have this disabled in production so we can wait. Thanks for
the quick response!

---

Reply to this email directly or view it on GitHub:
#126 (comment)

[jgeurts]

Just checking since there have been releases since this issue - has it been fixed?

[avanderhoorn]

We have fixed the issue but we haven't released the fix yet. We have a
branch on which we are working on the 1.0 release and it has the fix. If it
helps we may be able to do something to put out a patch for another pre 1.0
version, but weave been focused on getting 1.0 finished and out - does that
make sense? Let me know your thoughs.

On Monday, February 13, 2012, Jim Geurts <
reply@reply.github.com>
wrote:

Just checking since there have been releases since this issue - has it
been fixed?

---

Reply to this email directly or view it on GitHub:
#126 (comment)

A

[jgeurts]

Yep, makes sense. I can wait for the 1.0 release. Thanks for the update!

[NelsonReis]

After one day investigating some memory leaks, I've found out this issue.
I'll be waiting the update.

Thanks for your great work.

[hmata]

Since there was no update on this one for a long time, I just wanted to check if there will be a patch to fix it?
Or is 1.0 already close to being rolled out?
Cheers H

[avanderhoorn]

Hey guys
Just to provide an update on this. We have reimplemented the way that we are doing the dynamic proxies in v1 and think we have fixed this issues. It would be good to get some testing of it once we are good to go, but wanted to know that we haven't forgotten about this.Long story short - Castle has a cache so that it won't recreate proxies, and it looks like we where using it wrong, not very well documented.
Anyway more coming soon.
Cheers
Anthony

[thardy]

Any word on this? I had to drop Glimpse from a project a year and a half ago due to this. I'm starting a new project I'd like to use Glimpse with, and I was thinking that this would surely be fixed by now.

[nikmd23]

@thardy,

This has been fixed. Please take a look at RC1, currently available as a prerelease package on NuGet.

This issue will be closed as soon as we run Glimpse through a memory profiler, which we will do right before the final 1.0 release.

[nikmd23]

I've opened another issue #227 specifically to track the performance campaign I mentioned.

Since this specific issue has been fixed, I will now close it, however we are hoping to continue to tighten up performance as the final 1.0 release nears.