[Mono-dev] Remoting and thread pool limits

[Robert Jordan]

pablosantosluac wrote:
> Well, it is not a *bug* but a feature. I wonder if it should be changed. If 
> you look into RemotingThreadPool.cs there is a line like:
> 
> 
> threadDone.WaitOne(PoolGrowDelay, false);
> 
> 
> This one is actually the one making the process too slow. I'm afraid it must 
> be something similar on the .NET code too!
> 
> Of course removing this line the problem gets solved, but I guess there is a 
> reason in the channel to do that.

I noticed that too, but this doesn't solve the real problem: the 200
thread test is still too slow on my machine. The degradation seems to
start after 60-80 threads on my pretty weak SMP machine.

Just to be sure,  I've replaced RemotingThreadPool with an own, simple
version based on the standard BCL ThreadPool => same issue, although
I've raised the env var MONO_THREADS_PER_CPU to an insane value.

Robert

> 
> 
> pablo
> 
> 
> ----- Original Message ----- 
> From: "Robert Jordan" <robertj at gmx.net>
> To: <mono-devel-list at lists.ximian.com>
> Sent: Saturday, December 15, 2007 4:12 PM
> Subject: Re: [Mono-dev] Remoting and thread pool limits
> 
> 
>> Hi,
>>
>> pablosantosluac wrote:
>>> Hi,
>>>
>>> I've found the following difference working with .NET and Mono remoting. 
>>> In
>>> .NET when the remoting ThreadPool reaches the pool's maximum (25 threads 
>>> per
>>> process), it is able to continue creating new threads. In fact, you can 
>>> end
>>> up having a remoting server with hundreds of threads.
>>>
>>> In mono the behaviour is different. Once the limit is reached it starts
>>> refusing connections.
>> This is unrelated to mono's remoting thread pool. You have probably
>> ran your tests on Windows, where mono indeed fails with a GC failure
>> when too many threads are created because the GC has a hard coded
>> max thread count limit.
>>
>> On Linux (x86_64, Mono 1.2.6) I can finish the tests:
>>
>> Linux Mono client -> Linux Mono server (same machine)
>>
>> poseidon [~/foo] $ mono client/bin/Debug/client.exe
>> tcp://localhost:8084/remote
>> 1 - Time 1206 ms
>> 5 - Time 2045 ms
>> 10 - Time 3575 ms
>> 20 - Time 8174 ms
>> 40 - Time 12055 ms
>> 50 - Time 8185 ms
>> 200 - Time 46150 ms
>>
>>
>> MS.NET client -> Linux Mono server (different machines)
>>
>> troll:/cygdrive/u/foo/client/bin/Debug $ ./client.exe
>> tcp://poseidon:8084/remote
>> 1 - Time 1297 ms
>> 5 - Time 2000 ms
>> 10 - Time 3515 ms
>> 20 - Time 6016 ms
>> 40 - Time 11031 ms
>> 50 - Time 6016 ms
>> 200 - Time 94375 ms
>>
>>
>> The numbers don't look very well, though. I promise to look at
>> this when you file a bug report so that it doesn't get
>> overlooked.
>>
>> Robert
>>
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