mochiweb unstable?

[Damien Katz <da...@apache.org>]

I'm a bit worried about mochiweb right now. It appears that somehow,  
perhaps via a timing bug, mochiweb can get into a weird state and  
start returning the wrong response to a http request. It seems  
sometimes you get the result from a previous request, instead of the  
current request. This can be any type of request it seems, GET PUT or  
POST.  We see the problem consistently when running the tests from  
Safari, some people see it from Firefox too. The current theory is  
that Safari is faster and causes the timing bug more consistently than  
firefox.

This is a very bad thing. If our network interface doesn't give back  
correct results, then how can we call ourselves a database? If  
necessary, we'll have to revert back to the old inets httpd library.  
It may have been quirky, slow and under-documentend, but it was pretty  
solid once working. I hope that's not necessary.

Right now I think this bug is the highest priority and anyone is  
welcome to attack it.  https://issues.apache.org/jira/browse/COUCHDB-95

I don't have time this week to debug it, but if its still a problem by  
next week I'll start debugging and poking around more thoroughly  
inside mochiweb.

Any input or help is welcomed.

-Damien

Re: mochiweb unstable?

[Damien Katz <da...@apache.org>]

Okay, now I've confirmed the HTTP client is sending the POST more than  
once. Perhaps it is a the TCP layer resending packets? Curiouser and  
curiouser....


On Jul 15, 2008, at 4:46 PM, Damien Katz wrote:

> Okay, so I went ahead and did a little debugging. For reasons  
> unknown, mochiweb is getting a network error, causing us to crash.  
> Then it appears mochiweb attempts the same request again. This is  
> fine for GET PUT and DELETE, they'll error out if attempted twice,  
> but it also does it for POST during the creation of new documents.  
> This it would seem is the source of duplicate documents some people  
> see?
>
>
> On Jul 15, 2008, at 2:03 PM, Damien Katz wrote:
>
>> I'm a bit worried about mochiweb right now. It appears that  
>> somehow, perhaps via a timing bug, mochiweb can get into a weird  
>> state and start returning the wrong response to a http request. It  
>> seems sometimes you get the result from a previous request, instead  
>> of the current request. This can be any type of request it seems,  
>> GET PUT or POST.  We see the problem consistently when running the  
>> tests from Safari, some people see it from Firefox too. The current  
>> theory is that Safari is faster and causes the timing bug more  
>> consistently than firefox.
>>
>> This is a very bad thing. If our network interface doesn't give  
>> back correct results, then how can we call ourselves a database? If  
>> necessary, we'll have to revert back to the old inets httpd  
>> library. It may have been quirky, slow and under-documentend, but  
>> it was pretty solid once working. I hope that's not necessary.
>>
>> Right now I think this bug is the highest priority and anyone is  
>> welcome to attack it.  https://issues.apache.org/jira/browse/COUCHDB-95
>>
>> I don't have time this week to debug it, but if its still a problem  
>> by next week I'll start debugging and poking around more thoroughly  
>> inside mochiweb.
>>
>> Any input or help is welcomed.
>>
>> -Damien
>

Re: mochiweb unstable?

[Damien Katz <da...@apache.org>]

Okay, so I went ahead and did a little debugging. For reasons unknown,  
mochiweb is getting a network error, causing us to crash. Then it  
appears mochiweb attempts the same request again. This is fine for GET  
PUT and DELETE, they'll error out if attempted twice, but it also does  
it for POST during the creation of new documents. This it would seem  
is the source of duplicate documents some people see?


On Jul 15, 2008, at 2:03 PM, Damien Katz wrote:

> I'm a bit worried about mochiweb right now. It appears that somehow,  
> perhaps via a timing bug, mochiweb can get into a weird state and  
> start returning the wrong response to a http request. It seems  
> sometimes you get the result from a previous request, instead of the  
> current request. This can be any type of request it seems, GET PUT  
> or POST.  We see the problem consistently when running the tests  
> from Safari, some people see it from Firefox too. The current theory  
> is that Safari is faster and causes the timing bug more consistently  
> than firefox.
>
> This is a very bad thing. If our network interface doesn't give back  
> correct results, then how can we call ourselves a database? If  
> necessary, we'll have to revert back to the old inets httpd library.  
> It may have been quirky, slow and under-documentend, but it was  
> pretty solid once working. I hope that's not necessary.
>
> Right now I think this bug is the highest priority and anyone is  
> welcome to attack it.  https://issues.apache.org/jira/browse/COUCHDB-95
>
> I don't have time this week to debug it, but if its still a problem  
> by next week I'll start debugging and poking around more thoroughly  
> inside mochiweb.
>
> Any input or help is welcomed.
>
> -Damien