Re: A bug of multicore IO manager

Hi Kazu, What sort of workload was the mighty server under during those 1 or 2 days while you waited for it to become unresponsive. I.e. was this a production web server? Or were you generating requests at some frequency or leaving it mostly idle? -Andi On Tue, Sep 3, 2013 at 6:29 PM, Andreas Voellmy wrote:

Kazu, thanks for noticing this! I will try to recreate it on my server as well.

-Andi

On Tue, Sep 3, 2013 at 5:57 PM, Johan Tibell wrote:

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Hi Kazu,

On Tue, Sep 3, 2013 at 2:52 PM, Kazu Yamamoto wrote:

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Hi,

As I said before, I started running HTTP server using Mio in the real world. Unfortunately, the daemon is not stable.

After one day or so, the server cannot accept any HTTP requests. No error messages from the server.

The server is alive. To terminate the server (running in a "screen" terminal), single Ctrl-c is not enough. Typing Ctrl-c again terminates the server.

Could you run an strace on the process in this state so we can get an idea what it's doing?

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After several tests, I'm getting convinced that this occurs only when +RTS -N<x> is specified (where <x> >= 2). The server runs well if +RTS -N<x> is not specified.

That indicates that the problem is with the threaded RTS and perhaps with the IO manager.

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My question: if the program complied with GHC needs double Ctrl-c to terminate, what is the situation of the program?

If Ctrl+C generates an exception (does it?) there could be an overzealous exception catcher somewhere that catches all exceptions, including your Ctrl+C.

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P.S.

It seems to me that the server also is leaking space. The server is getting fatter gradually.

Could you use the profiler to see what type of objects are leaking?

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