Re: [Haskell-cafe] "too many open files" using snap
Forget to mention it, I am using HTTPS to serve all the APIs. And int the error.log file, I got lots of ConnectionAbruptlyTerminated exceptions, which I think is defined in OpenSSL. 在 2012-1-9，下午2:48， Gregory Collins 写道： > 2012/1/9 Eric Wong > Yes, I know it's not related to the static files now. But do I have to close > socket in snap monad? Shouldn't it be closed by snap-server? > > Without knowing what your code looks like one way or the other, it's hard to > tell. Snap does close the sockets it opens, of course. > > G > -- > Gregory Collins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
2012/1/9 Eric Wong > Yes, I know it's not related to the static files now. But do I have to > close socket in snap monad? Shouldn't it be closed by snap-server? > Without knowing what your code looks like one way or the other, it's hard to tell. Snap does close the sockets it opens, of course. G -- Gregory Collins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
Yes, I know it's not related to the static files now. But do I have to close socket in snap monad? Shouldn't it be closed by snap-server? 在 2012-1-9，下午2:29， Gregory Collins 写道： > 2012/1/9 Eric Wong > I run both of these commands and found out that there're sockets leaking. > Most of them are TCP connections in CLOSE_WAIT state. There're also some > socket with "can't identify protocol". > > So, What's the problem? Is it related to the timeout in the server config? > I'm using the default value. > > CLOSE_WAIT indicates that the other side has closed its side of the > connection and the OS is waiting for you to close() the socket. At this point > I'd start looking at your database layer. > > G > -- > Gregory Collins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
2012/1/9 Eric Wong > I run both of these commands and found out that there're sockets leaking. > Most of them are TCP connections in CLOSE_WAIT state. There're also some > socket with "can't identify protocol". > > So, What's the problem? Is it related to the timeout in the server config? > I'm using the default value. > CLOSE_WAIT indicates that the other side has closed its side of the connection and the OS is waiting for you to close() the socket. At this point I'd start looking at your database layer. G -- Gregory Collins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] How to use IndentParser. Any example/tutorial?
Hi, I need to construct a parser that parse a language that use indentation to define blocks as Python does. I ran into Text.ParserCombinators.Parsec.IndentParser module but have no idea how to use it. Can anyone point me out to how to use this module? Any short example, tutorial, or whatever would be highly appreciated. Thanks, Ed ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] numeric coercion in ghci vs hugs
After loading the one-line file default (Integer,Rational,Double) the input 1::Fractional t => t in ghci yields the output 1.0 and in hugs 1%1 The ghci answer appears not to respect the default declaration. What's going on? Doug McIlroy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
2012/1/8 Eric Wong : > I run both of these commands and found out that there're sockets leaking. > Most of them are TCP connections in CLOSE_WAIT state. There're also some > socket with "can't identify protocol". > > So, What's the problem? Is it related to the timeout in the server config? > I'm using the default value. > > Since they're sockets, it could be either the database connections or the HTTP connections, right? Is there some way you can insert a fake database layer to see if that makes your problem go away, to try and isolate the problem? Antoine > 在 2012-1-8，下午10:56， Brandon Allbery 写道： > > On Sun, Jan 8, 2012 at 09:50, Felipe Almeida Lessa > wrote: >> >> If you're on Linux, then you may >> >> $ ls -lah /proc/PID/fd >> >> to see where these open files are pointing to. > > > And on other systems lsof can determine this information. > > $ lsof -p PID > > -- > brandon s allbery allber...@gmail.com > wandering unix systems administrator (available) (412) 475-9364 vm/sms > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > > > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
I run both of these commands and found out that there're sockets leaking. Most of them are TCP connections in CLOSE_WAIT state. There're also some socket with "can't identify protocol". So, What's the problem? Is it related to the timeout in the server config? I'm using the default value. 在 2012-1-8，下午10:56， Brandon Allbery 写道： > On Sun, Jan 8, 2012 at 09:50, Felipe Almeida Lessa > wrote: > If you're on Linux, then you may > > $ ls -lah /proc/PID/fd > > to see where these open files are pointing to. > > And on other systems lsof can determine this information. > > $ lsof -p PID > > -- > brandon s allbery allber...@gmail.com > wandering unix systems administrator (available) (412) 475-9364 vm/sms > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] ANN: wxHaskell 0.13.2
On 5 January 2012 17:44, Jeremy O'Donoghue wrote: > > > The source repository at code.haskell.org has not yet been updated with > the patches. This will happen in the next day or so. > > The source repository at code.haskell.org has now been updated with wxHaskell 0.13.2 plus the two patches (add IOExtra to wxdirect and remove old-time from wxcore) from Shelarcy. I suggest a period of one more week (i.e. until 15th Jan 2012) for any further issues or fixes on the 0.13.2 series. After that, Dave, Eric and others will start to upload the changes needed to support wxWidgets 2.9.x. These changes will not work against wxWidgets 2.8.x installations, and are pretty significant in places. Please expect the main repo to unstable for a while after next Sunday. Best regards Jeremy ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple type-class experiment turns out not so simple...
On Sun, Jan 8, 2012 at 15:55, Christoph Breitkopf < chbreitk...@googlemail.com> wrote: > On Sun, Jan 8, 2012 at 9:25 PM, Brent Yorgey wrote: > >> On Fri, Jan 06, 2012 at 10:51:58AM +, Steve Horne wrote: >> > If I specify both extensions (-XMultiParamTypeClasses and >> > -XFlexibleInstances) it seems to work, but needing two language >> > extensions is a pretty strong hint that I'm doing it the wrong way. >> >> Not necessarily. These two extensions in particular (and especially >> the second) are quite uncontroversial. >> > > > http://hackage.haskell.org/trac/haskell-prime/wiki/MultiParamTypeClassesDilemma > > does not sound "uncontroversial" to me. That's why I avoided them so far. > MPTCs are not controversial. They're also of limited (but extant) usefulness without an additional extension; and, while there is "controversy" there, it's not especially relevant until type families are stabilized. They could in theory go into the standard *now*; they'd just be of limited use until functional dependencies vs. type families is settled. (Also, de facto I think it's already more or less been decided in favor of type families, just because functional dependencies are (a) a bit alien [being a glob of Prolog-style logic language imported into the middle of System Fc] and (b) [as I understand it] difficult to verify that the code in the compiler is handling all the potential corner cases right [mainly because of (a)]. In any case, if the code in question doesn't happen to need either functional dependencies or type classes, the controversy doesn't touch it. -- brandon s allbery allber...@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] cabal and conditional build-depends
Hi Cafe, I have a package that depends on several other Haskell libraries. One of these libraries depends on some native libraries (and associated headers) to build. I would like to make this dependency optional in my package if the libraries don't exist. To do this, I tried to switch my build-type from Simple to Configure in my .cabal file. Then I made a configure script that generates a .buildinfo file as suggested in the cabal guide. The buildinfo file is generated and looks as I would expect. If the library is found on the system, it has a "build-info: ..." line. Unfortunately, when Cabal processes it, it says: Warning: archive-inspection.buildinfo: Unknown fields: build-depends (line 2) Fields allowed in this section: buildable, build-tools, cpp-options, cc-options, ld-options, pkgconfig-depends, frameworks, c-sources, default-language, other-languages, default-extensions, other-extensions, extensions, extra-libraries, extra-lib-dirs, includes, install-includes, include-dirs, hs-source-dirs, other-modules, ghc-prof-options, ghc-shared-options, ghc-options, hugs-options, nhc98-options, jhc-options It really doesn't seem to like conditional build-depends entries. Is this expected behavior? And is there a better way to go about having conditional build-time dependencies on Haskell libraries using Cabal? I guess I could start playing with a custom Setup.hs, but I always hate doing that unless absolutely necessary. Thanks pgpNpgVCNacaI.pgp Description: PGP signature ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple type-class experiment turns out not so simple...
On Sun, Jan 8, 2012 at 9:25 PM, Brent Yorgey wrote: > On Fri, Jan 06, 2012 at 10:51:58AM +, Steve Horne wrote: > > > > If I specify both extensions (-XMultiParamTypeClasses and > > -XFlexibleInstances) it seems to work, but needing two language > > extensions is a pretty strong hint that I'm doing it the wrong way. > > Not necessarily. These two extensions in particular (and especially > the second) are quite uncontroversial. > I really don't know much about the subject, but http://hackage.haskell.org/trac/haskell-prime/wiki/MultiParamTypeClassesDilemma does not sound "uncontroversial" to me. That's why I avoided them so far. - Chris ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Simple type-class experiment turns out not so simple...
On Fri, Jan 06, 2012 at 10:51:58AM +, Steve Horne wrote: > > If I specify both extensions (-XMultiParamTypeClasses and > -XFlexibleInstances) it seems to work, but needing two language > extensions is a pretty strong hint that I'm doing it the wrong way. Not necessarily. These two extensions in particular (and especially the second) are quite uncontroversial. -Brent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Questions on the Haskell 2010 report
-BEGIN PGP SIGNED MESSAGE- Hash: SHA1 Thanks for the response > Pardon? As I read the spec you quoted, the former agrees with it > and the latter does not. How do you get the (illegal) latter? Oh, yes your right. I must have mixed up something. > If you don't name a module, the module is imputed to be Main and > the symbol main is exported from it. See the final paragraph of > Section 5.1. Didn't see that I also think I figured out number why there should be an error in number 3. Though I still thinks it's a very roundabout way of saying it Silvio -BEGIN PGP SIGNATURE- Version: GnuPG v1.4.11 (GNU/Linux) Comment: Using GnuPG with Mozilla - http://enigmail.mozdev.org/ iQIcBAEBAgAGBQJPCeimAAoJEDLsP+zrbatWtvQQALa58yEivnJ2BSvwZpAgDGKx SstxyoE2a4dxv+4bVfu2ngJzdtSGjP0Xf0vY7jTL4VO2aDO/uBbHW4wR/tzitEhI vsES1PBrHZHPO+pctVNqaKn9O738tDktF2KU7wu789epTafvkQKeNbmlloZfMrkB W0IlWHsWW3BaqdmBXb8M7nGaBUPyX1iLH3lXU5M5BQnWndv/99A0k+fuoj//TvwI w6N2ct6mI12ohVbBi8xmSANvel5ZePRi4mj3GfnGtFuETRqxqRd/IQNb0VjgTx1k UlpbHA7GDV2OtRavMu0BlfRdYwQJ/eIinFhd3mT1ICZ3mBtbTsZC5JBQi1x4EbFJ /jgFU4DWdskIT3RXjiKXAQxDRRwtvFhqDVA3OxZeKBZAMAVUCvcAGwWpGNMD27/3 OkUptukFkHil6KGUbY3K6IwkGKMK5aBuHOl2ZxCHjZo3rnskfQz8CIk34Dxv/mOG idhZhT/EGv3nkKH0ny1zUEgkFHmkJRS9ytp36ubi1cC4ptTPOkUt6cIeFEhCMmCH bcWIZez1c7xvkTygbQAF6kj8V4vwgxwmYxjga5/kn4toRRmuD6anY/DZd5JJ4/2E RgI24R7hJlBmZLoNpNBOlyhMoDWfE5baECZH2IGiJq+mREskIBVui64LsL5xqJCP gvR1od0nzAkZkHNoowew =Egb5 -END PGP SIGNATURE- ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] Questions on the Haskell 2010 report
On Sun, Jan 8, 2012 at 12:53, Silvio Frischknecht
wrote:
>module → module modid [exports] where body
>| body
>body→ { impdecls ; topdecls }
>| { impdecls }
>| { topdecls }
>
> You can't see it in this mail because there is no font but
> the curly braces { } are meant to match the tokens { } and are not
> meant as repetition. However, as I understand it, the layout parser
> would modify this code:
>
>module Foo where
>import Bar
>baz=baz
>
> to this code (which doesn't match):
>
>module Foo where { import Bar ; baz=baz }
>
> and not to this code (which would be required to match):
>
>module Foo where { { import Bar } ; { baz=baz } }
>
Pardon? As I read the spec you quoted, the former agrees with it and the
latter does not. How do you get the (illegal) latter?
2)
> In the same section what is it supposed to mean if "module" consists
> of only a "body" and not "module modid [exports] where body".
>
If you don't name a module, the module is imputed to be Main and the symbol
main is exported from it. See the final paragraph of Section 5.1.
--
brandon s allbery allber...@gmail.com
wandering unix systems administrator (available) (412) 475-9364 vm/sms
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[Haskell-cafe] Questions on the Haskell 2010 report
-BEGIN PGP SIGNED MESSAGE-
Hash: SHA1
I am trying to write a haskell compiler and i have stumbled upon 2
issues that i don't understand in the Haskell report 2010. Btw. these
issues are also present in the 98 report.
1)
first is this in section 5.1 Module Structure [1]. A module is defined
like this.
module → module modid [exports] where body
| body
body→ { impdecls ; topdecls }
| { impdecls }
| { topdecls }
You can't see it in this mail because there is no font but
the curly braces { } are meant to match the tokens { } and are not
meant as repetition. However, as I understand it, the layout parser
would modify this code:
module Foo where
import Bar
baz=baz
to this code (which doesn't match):
module Foo where { import Bar ; baz=baz }
and not to this code (which would be required to match):
module Foo where { { import Bar } ; { baz=baz } }
So as i see the definition should state this instead:
module → module modid [exports] where body
| body
body→ { impdecls ; topdecls }
| impdecls
| topdecls
2)
In the same section what is it supposed to mean if "module" consists
of only a "body" and not "module modid [exports] where body".
3)
In section 10.3 Layout [2] it is written.
If a let, where, do, or of keyword is not followed by the lexeme {,
the token {n} is inserted after the keyword, where n is the
indentation of the next lexeme if there is one, or 0 if the end of
file has been reached.
Together with this rule
L [] (m : ms) = } : L [] ms if m≠0 (Note 6)
This results in an error if the program ends in a "where", ...
Wouldn't it make more sense to put a {1} in case of EOF or just insert
the tokens '{' and '}'. On the other hand if you really won't accept
that why not simply say that it is an error.
btw. GHC doesn't give an error.
[1]
http://www.haskell.org/onlinereport/haskell2010/haskellch5.html#x11-990005.1
[2]
http://www.haskell.org/onlinereport/haskell2010/haskellch10.html#x17-17800010.3
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Re: [Haskell-cafe] [web-devel] [ANNOUNCE] First release of crypto-conduit
Aristid Breitkreuz wrote: > To use the hash, I have to convert it to a ByteString, and then I > suddenly have lost all this safety. I don't really see how there is > any real safety gained. But that isn't true for all users. Sometimes a hash is computed long before it is transmitted, so while you're passing it around you can be sure it won't be confused with other raw data (basically, what Vincent said). Also, some users never want to convert to a bytestring - using the Eq and Ord instances are enough. > That said, just exposing a direct method of getting to that ByteString > without cereal (as Thomas proposed) would be an improvement. I'll do this and release crypto-api 0.9 soonish. Cheers, Thomas > > > > Aristid > > > 2012/1/8 Vincent Hanquez : >> On 01/08/2012 04:12 AM, Aristid Breitkreuz wrote: >>> >>> Why? I don't actually need the hash object for anything, usually. All >>> I need is the ByteString, and then I need to learn how to use the >>> cereal package to get it... >> >> The whole rationale i believe, is having meaningful types associated to your >> values so that the type checker can do its job. i.e. you don't start mixing >> a hash (in binary form) and a random piece of file. >> >> My only problem with the Serialize instance, is that dependencies (cereal in >> this case) trickle through to the user of the API, which would be solved by >> Thomas' suggestion. >> >> -- >> Vincent > > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org > http://www.haskell.org/mailman/listinfo/haskell-cafe ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] RoseTree + Data.Typeable.Zipper
2012/1/8 Sergey Mironov
> Hi list!
> Could you please give me a quick example of navigating throw
> Data.Typeable.Zipper built on top of a Rose Tree?
> eg. (See ??? in the last line - is my question)
>
> {-#LANGUAGE TemplateHaskell, DeriveDataTypeable, TypeOperators #-}
>
> import Data.Typeable.Zipper
>
> data Tree k a = Tree {
> _rules :: [(k,Tree k a)]
> } deriving(Show, Typeable)
>
> $(mkLabelsNoTypes [''Tree])
>
> atree = Tree [(1, Tree []), (2, Tree []), (3, Tree [(11, Tree [])])]
>
> moveToLeftmostChild :: (Typeable k, Typeable a) =>
> Zipper1 (Tree k a) -> Zipper1 (Tree k a)
> moveToLeftmostChild z = moveTo ??? z
>
> Thanks,
> Sergey
>
Heh, look like I've found the solution by myself! Here is the missing part:
get_child n t = ((_rules t) !! n) -- fast'n'diry
set_child n c t = t{ _rules = (hs ++ (c:ts)) } where
(hs,ts) = splitAt n (_rules t)
focus_child :: Int -> Tree k a :-> (k, Tree k a)
focus_child n = lens (get_child n) (set_child n)
moveToLeftmostChild :: (Ord k, Typeable k, Typeable a)
=> Zipper (Tree k a) (Tree k a) -> Zipper (Tree k a) (k, Tree k a)
moveToLeftmostChild z = moveTo (focus_child 0) z
Thanks,
Sergey
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Re: [Haskell-cafe] All the random packages
On 08.01.2012 11:18, Eugene Kirpichov wrote: Hi, I came across the beautiful algorithm for O(1) generation of rational discrete distributions http://www.keithschwarz.com/darts-dice-coins/ and though it'd be fun to implement it in Haskell and put on Hackage, but then it turned out that there's about a dozen random number packages, so I'm not sure to which one to contribute, or better to roll out my own package and encourage authors of the other packages to reference it and fit under their interface. I think it was first described in the paper "Fast generation of discrete random variables" by Marsaglia et.al.[1] It's called squared histogram method in the paper. Another one is quite elegand as well. They claim claim that these algorithms are fastest. Also I would avoid floating point numbers for following reasons. They are tricky and difficult to reason about. Random numbers are generated as words and conversion to float/double will inevitable lose some entropy. Which random number packages are considered to be most mature or perhaps promising - i.e., contributing to which ones will bring the community the most benefit? Difficult to say. Reverse dependencies[2] could be of interest. Is there any effort on unifying them going on? I'm not aware about such thing, [1] http://ideas.repec.org/a/jss/jstsof/11i03.html [2] http://packdeps.haskellers.com/reverse ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
This is very helpful, I found currently almost all of the open files are sockets. But it don't have that much traffic. So it seems it's leaking socket file descriptors. 在 2012-1-8，下午10:50， Felipe Almeida Lessa 写道： > On Sun, Jan 8, 2012 at 12:27 PM, Gregory Collins > wrote: >> A "too many open files" error is usually due to running out of file >> descriptors for network sockets. On my Linux machine the per-process limit >> for file descriptors defaults to 1024, and on my Mac the default is 256. You >> can see your current limit by running "ulimit -a" from the terminal. > > If you're on Linux, then you may > > $ ls -lah /proc/PID/fd > > to see where these open files are pointing to. > > HTH, > > -- > Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [web-devel] [ANNOUNCE] First release of crypto-conduit
On 01/08/2012 02:35 PM, Aristid Breitkreuz wrote: To use the hash, I have to convert it to a ByteString, and then I suddenly have lost all this safety. I don't really see how there is any real safety gained. Using the hash and carrying it around are two different things. You don't get any usefulness once you have converted it indeed, but before hand this is quite handy sometimes. It's very similar to phantom types or newtype-ing. It also have a useful self-documentation factor, for example the later tell the user of "myFunction" more information than the former: myFunction :: ByteString -> ByteString -> SomeType myFunction :: ByteString -> Hash SHA1 -> SomeType -- Vincent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
On Sun, Jan 8, 2012 at 09:50, Felipe Almeida Lessa wrote: > If you're on Linux, then you may > > $ ls -lah /proc/PID/fd > > to see where these open files are pointing to. > And on other systems lsof can determine this information. $ lsof -p PID -- brandon s allbery allber...@gmail.com wandering unix systems administrator (available) (412) 475-9364 vm/sms ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
On Sun, Jan 8, 2012 at 12:27 PM, Gregory Collins wrote: > A "too many open files" error is usually due to running out of file > descriptors for network sockets. On my Linux machine the per-process limit > for file descriptors defaults to 1024, and on my Mac the default is 256. You > can see your current limit by running "ulimit -a" from the terminal. If you're on Linux, then you may $ ls -lah /proc/PID/fd to see where these open files are pointing to. HTH, -- Felipe. ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
Not knowing how exactly you set up your interop with mysql, is there any chance your application tries to keep too many mysql connections open? A simple "show processlist;" inside of a mysql console should rule out this possibility. Also, are you reading to or writing from any files at any point independently of the snap infrastructure? I have had issues in the past with intermittent background file reads not being strict enough and eventually starving the system of file descriptors. Cheers, Ozgun On Sunday, January 8, 2012 at 4:27 PM, Gregory Collins wrote: > On Sun, Jan 8, 2012 at 7:25 AM, Eric Wong (mailto:wsy...@gmail.com)> wrote: > > Hi haskellers, > > > > I wrote a web server using snap framework. Basically, it's an API server > > using hdbc-mysql to connect to a mysql server. But it also serves some > > static web pages and images, using the serveDirectory function in > > snap-core. The program eats more and more memory slowly, but I couldn't > > spot the leak. It uses less than 10MB memory when starting. Sometimes, it > > can grow to 60-70MB and stop working correctly. Then I find that the log > > file is full of "too many open files" error. As I don't have any code open > > any files, I suspect it's the serveDirectory leaking. But I don't have any > > expertise on the core of snap, so, could some one give me some advice on > > this problem? > > I'm fairly certain there's no leak in Snap in this code, although I will > gladly accept evidence to the contrary -- I've been load-testing > "serveDirectory" at 20,000 qps for a couple of minutes now, with no increase > in the memory resident size. > > A "too many open files" error is usually due to running out of file > descriptors for network sockets. On my Linux machine the per-process limit > for file descriptors defaults to 1024, and on my Mac the default is 256. You > can see your current limit by running "ulimit -a" from the terminal. > > Each incoming socket occupies a file descriptor, as does every open > connection to your database and every open file. When these run out, calls to > accept() or to open files start failing and you get this error message. > > Memory profiling should help you find the leak. > > G > -- Gregory Collins mailto:g...@gregorycollins.net)> > ___ > Haskell-Cafe mailing list > Haskell-Cafe@haskell.org (mailto:Haskell-Cafe@haskell.org) > http://www.haskell.org/mailman/listinfo/haskell-cafe > > ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] [web-devel] [ANNOUNCE] First release of crypto-conduit
To use the hash, I have to convert it to a ByteString, and then I suddenly have lost all this safety. I don't really see how there is any real safety gained. That said, just exposing a direct method of getting to that ByteString without cereal (as Thomas proposed) would be an improvement. Aristid 2012/1/8 Vincent Hanquez : > On 01/08/2012 04:12 AM, Aristid Breitkreuz wrote: >> >> Why? I don't actually need the hash object for anything, usually. All >> I need is the ByteString, and then I need to learn how to use the >> cereal package to get it... > > The whole rationale i believe, is having meaningful types associated to your > values so that the type checker can do its job. i.e. you don't start mixing > a hash (in binary form) and a random piece of file. > > My only problem with the Serialize instance, is that dependencies (cereal in > this case) trickle through to the user of the API, which would be solved by > Thomas' suggestion. > > -- > Vincent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] "too many open files" using snap
On Sun, Jan 8, 2012 at 7:25 AM, Eric Wong wrote: > Hi haskellers, > > I wrote a web server using snap framework. Basically, it's an API server > using hdbc-mysql to connect to a mysql server. But it also serves some > static web pages and images, using the serveDirectory function in > snap-core. The program eats more and more memory slowly, but I couldn't > spot the leak. It uses less than 10MB memory when starting. Sometimes, it > can grow to 60-70MB and stop working correctly. Then I find that the log > file is full of "too many open files" error. As I don't have any code open > any files, I suspect it's the serveDirectory leaking. But I don't have any > expertise on the core of snap, so, could some one give me some advice on > this problem? > I'm fairly certain there's no leak in Snap in this code, although I will gladly accept evidence to the contrary -- I've been load-testing "serveDirectory" at 20,000 qps for a couple of minutes now, with no increase in the memory resident size. A "too many open files" error is usually due to running out of file descriptors for network sockets. On my Linux machine the per-process limit for file descriptors defaults to 1024, and on my Mac the default is 256. You can see your current limit by running "ulimit -a" from the terminal. Each incoming socket occupies a file descriptor, as does every open connection to your database and every open file. When these run out, calls to accept() or to open files start failing and you get this error message. Memory profiling should help you find the leak. G -- Gregory Collins ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
[Haskell-cafe] RoseTree + Data.Typeable.Zipper
Hi list!
Could you please give me a quick example of navigating throw
Data.Typeable.Zipper built on top of a Rose Tree?
eg. (See ??? in the last line - is my question)
{-#LANGUAGE TemplateHaskell, DeriveDataTypeable, TypeOperators #-}
import Data.Typeable.Zipper
data Tree k a = Tree {
_rules :: [(k,Tree k a)]
} deriving(Show, Typeable)
$(mkLabelsNoTypes [''Tree])
atree = Tree [(1, Tree []), (2, Tree []), (3, Tree [(11, Tree [])])]
moveToLeftmostChild :: (Typeable k, Typeable a) =>
Zipper1 (Tree k a) -> Zipper1 (Tree k a)
moveToLeftmostChild z = moveTo ??? z
Thanks,
Sergey
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Re: [Haskell-cafe] [web-devel] [ANNOUNCE] First release of crypto-conduit
On 01/08/2012 04:12 AM, Aristid Breitkreuz wrote: Why? I don't actually need the hash object for anything, usually. All I need is the ByteString, and then I need to learn how to use the cereal package to get it... The whole rationale i believe, is having meaningful types associated to your values so that the type checker can do its job. i.e. you don't start mixing a hash (in binary form) and a random piece of file. My only problem with the Serialize instance, is that dependencies (cereal in this case) trickle through to the user of the API, which would be solved by Thomas' suggestion. -- Vincent ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
Re: [Haskell-cafe] OpenAL bindings?
Hi, On Sun, 08 Jan 2012 16:49:40 +0900, Jason Dagit wrote: I see that the following darcs repositories are available on the community server: http://code.haskell.org/OpenAL/OpenAL http://code.haskell.org/OpenAL/ALUT Hope this helps, Thank you so much! Someone (I guess that's me) should update the wiki. I updated link in OpenAL page now. Best Regards, On Sat, Jan 7, 2012 at 1:26 PM, Yitzchak Gale wrote: Jason Dagit wrote: Looks like the repo [1] for the OpenAL bindings that Sven Panne created [2] is no longer available. I assume this is a result of The Great Server Outage of 2011 [3]. [1] http://darcs.haskell.org/packages/OpenAL/ [2] http://hackage.haskell.org/cgi-bin/hackage-scripts/package/OpenAL [3] http://www.haskell.org/pipermail/haskell-cafe/2011-February/088829.html No, darcs.haskell.org is not the community server. It is a separate server that seems to be located at Galois. Ah yes, I always forget which servers are where. -- shelarcy http://page.freett.com/shelarcy/ ___ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
