[Haskell-cafe] Can a GC delay TCP connection formation?

[Gershom Bazerman]

On 11/27/12 2:17 PM, Jason Dagit wrote:
>
> Based on that I would check the FFI imports in your database library. 
> In the best case (-threaded, 'safe', and thread-safe odbc), I think 
> you'll find that N of these can run concurrently, but here your number 
> of requests is likely to be much greater than N (where N is the number 
> of threads the RTS created with +RTS -N).
>
HDBC-odbc has long used the wrong type of FFI imports, resulting in 
long-running database queries potentially blocking all other IO. I just 
checked, and apparently a patch was made to the repo in September that 
finally fixes this [1], but apparently a new release has yet to be 
uploaded to hackage. In any case, if you try to install it from the 
repo, this may at least solve some of your problems.

[1] 
https://github.com/hdbc/hdbc-odbc/commit/7299d3441ce2e1d5a485fe79b37540c0a44a44d4

--Gershom