Hi Everyone, I'm new to the list, been on irc a bit. I'm still learning haskell. Wanted to say Hi before getting in to things... I'm interested in real-world programs in haskell, especially ones where security and formal methods are important. I'm looking at web servers right now. I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code. I've been able to get the code to compile after a while, but it still has some warnings of deprecated features which I havent been able to get rid of (if anyone's interested in helping out, let me know). Anyway, I configured it an ran it and it works, although I have noticed two security flaws in it which need fixing. Is it possible there is a newer version with these flaws fixed? Besides HWS, what other web servers exist? Does anyone actually use a haskell based web server in practice? Which web server is considered the most mature? stable? fastest? I'm trying to decided if I should sink some time into HWS or if I should use another server. Tim Newsham http://www.lava.net/~newsham/
I don't know if there's anything newer, but you could check out:
http://happs.org/HAppS/README.html
http://www.informatik.uni-freiburg.de/~thiemann/WASH/
Hope that helps,
Jared.
On 4/8/06, Tim Newsham
Hi Everyone, I'm new to the list, been on irc a bit. I'm still learning haskell. Wanted to say Hi before getting in to things...
I'm interested in real-world programs in haskell, especially ones where security and formal methods are important. I'm looking at web servers right now. I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code. I've been able to get the code to compile after a while, but it still has some warnings of deprecated features which I havent been able to get rid of (if anyone's interested in helping out, let me know). Anyway, I configured it an ran it and it works, although I have noticed two security flaws in it which need fixing. Is it possible there is a newer version with these flaws fixed?
Besides HWS, what other web servers exist? Does anyone actually use a haskell based web server in practice? Which web server is considered the most mature? stable? fastest?
I'm trying to decided if I should sink some time into HWS or if I should use another server.
Tim Newsham http://www.lava.net/~newsham/ _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
-- http://www.updike.org/~jared/ reverse ")-:"
On Sat, 8 Apr 2006, Tim Newsham wrote:
Hi Everyone, I'm new to the list, been on irc a bit. I'm still learning haskell. Wanted to say Hi before getting in to things...
I'm interested in real-world programs in haskell, especially ones where security and formal methods are important. I'm looking at web servers right now. I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code. I've been able to get the code to compile after a while, but it still has some warnings of deprecated features which I havent been able to get rid of (if anyone's interested in helping out, let me know). Anyway, I configured it an ran it and it works, although I have noticed two security flaws in it which need fixing. Is it possible there is a newer version with these flaws fixed?
I also tried installing HWS, did not succeed in using the default build procedure because of too many dependencies, and also getting the warnings about the deprecated features you mention. Eventually I got it running but it ran into heap overflow after some time of running. :-(
I'm trying to decided if I should sink some time into HWS or if I should use another server.
The web-server provided with WASH works for me, but it is hard to compile, because there are some huge Haskell modules included.
Following is a message I sent yesterday, sans attachment. Looks like the code was too bloated to get through under the list size limit. As I say in the original message , I'm keen for any feedback. So let me know if anyone wants the actual code (20 KB, compressed) to have a look through. Cheerio Daniel On Sunday 09 April 2006 06:24, Tim Newsham wrote:
I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code.
There's this link: http://www.mdstud.chalmers.se/~md9ms/hws-wp/ From memory I think there may have been a more recent version at scannedinavian.org (possibly only accessible with darcs?), but still a couple of years with no apparent activity.
Besides HWS, what other web servers exist? Does anyone actually use a haskell based web server in practice? Which web server is considered the most mature? stable? fastest?
I'm trying to decided if I should sink some time into HWS or if I should use another server.
Several months ago I had a bit of play-time available which I spent on writing a HTTP server in Haskell. The goal was a HTTP 1.1 compliant server that could be embedded in a Haskell app, be reconfigured on the fly and have different request handlers added/removed. I did have a quick look at HWS before I started but I seem to recall it was pretty basic (in terms of the amount of the HTTP spec. implemented). In any event, I started from scratch. It's certainly not finished, and it's the very first thing I wrote with Haskell so it's a bit of a dogs breakfast, but it might be of interest. There's lots that needs doing but it should just be a case of writing a request handler to get it doing _something_ useful. It's always been my intention to get back to it, clean it up a bit/lot and release it under a more liberal licence (currently 'all rights reserved'), but have had little time available. Eventually I hope to actually use it in anger. If anyone is interested in using it, contributing to it, or picking over it for use in an existing project, I'll try and find somewhere stable to host it and change the licence. Feel free to ask questions on what it does/doesn't do. You'll probably need to, given the documentation ;-) Regardless of it's utility, any criticism or advice on the code would be appreciated. Daniel
I'm interested, but I don't have the time to look right now (or in the next couple of months, as far as I can see). What would really interest me is a system that can provide the functionality of the Python packages I currently use (TurboGears [1], of which the web server/controller component is CherryPy [2]). There's also some interesting recent CherryPy-related discussion about web dispatching that I think could translate very well to Haskell [3][4]. ... I'd also be interested in a system that handled overlapped asynchronous requests in a fashion not dissimilar to Twisted [5]. I've very recently been playing with Twisted as a way to deal with large numbers of overlapping lightweight requests without having large numbers of active threads. Twisted requires one to string together asynchronous callbacks to assemble a process that completes over time. It seems to me that the sequencing of asynchronous operations is very much like threading computations in a monad, and that the higher-order functions on monads could also be used for composition of asynchronous operations. I just implemented a "sequence" function for Twisted operations whose implementation started to feel very like "foldr". This can't be new, and I'm wondering if there is any interesting work out there on using monads for multiple asynchronous I/O operations. (And, much as I'd love to use Haskell for this, is there work that would translate cleanly to Python?) #g -- [1] http://www.turbogears.com/ [2] http://www.cherrypy.org/ [3] http://pythonpaste.org/do-it-yourself-framework.html (cf. descriptions of object publishing) [4] The above link was posted in this discussion thread: http://groups.google.com/group/cherrypy-users/browse_frm/thread/47035d8d78adad69/bf02b489e45ce6c5?tvc=1&hl=en#bf02b489e45ce6c5 [5] http://twistedmatrix.com/ http://twistedmatrix.com/projects/core/ Daniel McAllansmith wrote:
Following is a message I sent yesterday, sans attachment. Looks like the code was too bloated to get through under the list size limit.
As I say in the original message , I'm keen for any feedback. So let me know if anyone wants the actual code (20 KB, compressed) to have a look through.
Cheerio Daniel
On Sunday 09 April 2006 06:24, Tim Newsham wrote:
I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code.
There's this link: http://www.mdstud.chalmers.se/~md9ms/hws-wp/
From memory I think there may have been a more recent version at scannedinavian.org (possibly only accessible with darcs?), but still a couple of years with no apparent activity.
Besides HWS, what other web servers exist? Does anyone actually use a haskell based web server in practice? Which web server is considered the most mature? stable? fastest?
I'm trying to decided if I should sink some time into HWS or if I should use another server.
Several months ago I had a bit of play-time available which I spent on writing a HTTP server in Haskell. The goal was a HTTP 1.1 compliant server that could be embedded in a Haskell app, be reconfigured on the fly and have different request handlers added/removed. I did have a quick look at HWS before I started but I seem to recall it was pretty basic (in terms of the amount of the HTTP spec. implemented).
In any event, I started from scratch. It's certainly not finished, and it's the very first thing I wrote with Haskell so it's a bit of a dogs breakfast, but it might be of interest. There's lots that needs doing but it should just be a case of writing a request handler to get it doing _something_ useful.
It's always been my intention to get back to it, clean it up a bit/lot and release it under a more liberal licence (currently 'all rights reserved'), but have had little time available. Eventually I hope to actually use it in anger.
If anyone is interested in using it, contributing to it, or picking over it for use in an existing project, I'll try and find somewhere stable to host it and change the licence. Feel free to ask questions on what it does/doesn't do. You'll probably need to, given the documentation ;-)
Regardless of it's utility, any criticism or advice on the code would be appreciated.
Daniel _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
-- Graham Klyne For email: http://www.ninebynine.org/#Contact
On Wednesday 12 April 2006 22:52, Graham Klyne wrote:
I'm interested, but I don't have the time to look right now (or in the next couple of months, as far as I can see).
What would really interest me is a system that can provide the functionality of the Python packages I currently use (TurboGears [1], of which the web server/controller component is CherryPy [2]). There's also some interesting recent CherryPy-related discussion about web dispatching that I think could translate very well to Haskell [3][4].
It's certainly nothing that grand. It's intended scope was confined to accepting connections, decoding requests and handing them off to arbitrary request handlers which is where all that higher level stuff would come into play. I just had a look at Network.HTTP, looks like there have been some recent changes to allow server-side uses. Perhaps that could be a home for parts of it, though the two approaches seem a bit different. Daniel
I have HWS and HWS-WP running in GHC 6.4.2. I used dons' hs-plugins library for dynamic loading since the library used by hws-wp looks to be dated. The code can be found at: http://udp110165uds.hawaiiantel.net:8888/hws/ which is incidentally running hws-wp. Tim Newsham http://www.lava.net/~newsham/
I'd also be interested in a system that handled overlapped asynchronous requests in a fashion not dissimilar to Twisted [5].
I see you just saw the HAppS announcement. You'll appreciate that HAppS was actually inspired by Twisted (and Prevayler).
over time. It seems to me that the sequencing of asynchronous operations is very much like threading computations in a monad, and that the higher-order functions on monads could also be used for composition of asynchronous operations.
Yup you got it. The two big issues are ACID semantics (for any server) and handling of side effects. HAppS does write ahead logging and checkpointing to give you the ACID stuff and provides infrastructure so you can guarantee at-least-once execution of side effects. As for "web dispatching", the application model in HAppS is to help you separate state, application logic, wire formats, protocols, and presentation layer: * State State is just a haskell data type you define. ACID Consistency enforced by Haskell's type system. ACID Durability is handled by MACID write-ahead logging and checkpointing. * Application Incoming events are gathered in individual haskell threads and then pushed onto a single application queue for processing. The queue model gives you ACID Atomicity and Isolation and lets your app be simply a set of functions with types like: SomeInputType -> MACID SomeOutputType The MACID monad lets you update your state and *schedule* side-effects. To be clear, MACID is not in the IO monad so you cannot execute sideeffects, you can only schedule them. The framework takes care of making sure they are executed at-least-once (if they can be completed by a deadline you specify). * Wire Formats Since your app consists of a set of functions with various haskell input and output types, somewhere you need a place to convert between those internal haskell types and external protocol event types; e.g. from URLEncoded HTTP requests to SomeInputType and from SomeOutputType to XML encoded HTTP responses. * Protocols HAppS currently provides support for HTTP Requests/Responses and SMTP Envelopes. To be clear HApps provides ACID Atomicity at the protocol event level. So if you write a protocol with SMTP envelopes being the arriving event type then your app will have atomicity in processing incoming SMTP envelopes. If you write a protocol with SMTP commands being the arriving event type, then your app will have atomicity at the level of individual smtp commands. * Presentation If your application outputs XML as its wire format, HAppS provides a lot of support for using XSLT to transform it for presentation purposes. For example, you can send XML mail and HAppS will take care of applying the relevant XSLT stylesheet before it is delivered. If you output XML HTTP responses, HAppS takes care of applying the XSLT stylesheet server side for user-agents that don't support doing so on the client. The value here is that you can have designer types who know XSLT modify presentation stuff without touching your application code. -Alex- ______________________________________________________________ S. Alexander Jacobson tel:917-770-6565 http://alexjacobson.com On Wed, 12 Apr 2006, Graham Klyne wrote:
I'm interested, but I don't have the time to look right now (or in the next couple of months, as far as I can see).
What would really interest me is a system that can provide the functionality of the Python packages I currently use (TurboGears [1], of which the web server/controller component is CherryPy [2]). There's also some interesting recent CherryPy-related discussion about web dispatching that I think could translate very well to Haskell [3][4].
...
I'd also be interested in a system that handled overlapped asynchronous requests in a fashion not dissimilar to Twisted [5]. I've very recently been playing with Twisted as a way to deal with large numbers of overlapping lightweight requests without having large numbers of active threads. Twisted requires one to string together asynchronous callbacks to assemble a process that completes over time. It seems to me that the sequencing of asynchronous operations is very much like threading computations in a monad, and that the higher-order functions on monads could also be used for composition of asynchronous operations. I just implemented a "sequence" function for Twisted operations whose implementation started to feel very like "foldr".
This can't be new, and I'm wondering if there is any interesting work out there on using monads for multiple asynchronous I/O operations. (And, much as I'd love to use Haskell for this, is there work that would translate cleanly to Python?)
#g --
[1] http://www.turbogears.com/
[3] http://pythonpaste.org/do-it-yourself-framework.html (cf. descriptions of object publishing)
[4] The above link was posted in this discussion thread: http://groups.google.com/group/cherrypy-users/browse_frm/thread/47035d8d78adad69/bf02b489e45ce6c5?tvc=1&hl=en#bf02b489e45ce6c5
[5] http://twistedmatrix.com/ http://twistedmatrix.com/projects/core/
Daniel McAllansmith wrote:
Following is a message I sent yesterday, sans attachment. Looks like the code was too bloated to get through under the list size limit.
As I say in the original message , I'm keen for any feedback. So let me know if anyone wants the actual code (20 KB, compressed) to have a look through.
Cheerio Daniel
On Sunday 09 April 2006 06:24, Tim Newsham wrote:
I found a copy of Simon Marlow's HWS on haskell.org's cvs server. I know there's a newer plugin version, but I cant find a working link to the actual code.
There's this link: http://www.mdstud.chalmers.se/~md9ms/hws-wp/
From memory I think there may have been a more recent version at scannedinavian.org (possibly only accessible with darcs?), but still a couple of years with no apparent activity.
Besides HWS, what other web servers exist? Does anyone actually use a haskell based web server in practice? Which web server is considered the most mature? stable? fastest?
I'm trying to decided if I should sink some time into HWS or if I should use another server.
Several months ago I had a bit of play-time available which I spent on writing a HTTP server in Haskell. The goal was a HTTP 1.1 compliant server that could be embedded in a Haskell app, be reconfigured on the fly and have different request handlers added/removed. I did have a quick look at HWS before I started but I seem to recall it was pretty basic (in terms of the amount of the HTTP spec. implemented).
In any event, I started from scratch. It's certainly not finished, and it's the very first thing I wrote with Haskell so it's a bit of a dogs breakfast, but it might be of interest. There's lots that needs doing but it should just be a case of writing a request handler to get it doing _something_ useful.
It's always been my intention to get back to it, clean it up a bit/lot and release it under a more liberal licence (currently 'all rights reserved'), but have had little time available. Eventually I hope to actually use it in anger.
If anyone is interested in using it, contributing to it, or picking over it for use in an existing project, I'll try and find somewhere stable to host it and change the licence. Feel free to ask questions on what it does/doesn't do. You'll probably need to, given the documentation ;-)
Regardless of it's utility, any criticism or advice on the code would be appreciated.
Daniel _______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
-- Graham Klyne For email: http://www.ninebynine.org/#Contact
_______________________________________________ Haskell-Cafe mailing list Haskell-Cafe@haskell.org http://www.haskell.org/mailman/listinfo/haskell-cafe
participants (6)
-
Daniel McAllansmith -
Graham Klyne -
Henning Thielemann -
Jared Updike -
S. Alexander Jacobson -
Tim Newsham