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From Florian Müller <f...@apache.org>
Subject Re: CXF support as web services stack in opencmis
Date Fri, 22 Mar 2013 16:00:56 GMT
 Hi Daniel,

 Thanks for the clarifications. The foundation of the OpenCMIS Web 
 Services code has been written in 2009. We evaluated CFX at this point 
 and concluded that we have to go with RI. CXF couldn't handle 
 attachments in the way we needed it. It looks like a lot has changed 
 since then.

 But even if the content is buffered in a temporary file, this is an 
 issue - at least on the client side. Two real world examples:
 - There are business requirements not to store any confidential 
 documents unencrypted on a hard disk. A temporary file would violate 
 this.
 - A document could be a 4GB video file. Apart from the performance 
 penalty of buffering it on disk, the client has to have enough free temp 
 space.

 True content streaming is not a nice-to-have; it's a real requirement. 
 Storing the content on disks prevents Out Of Memory exceptions, but 
 opens another can of worms.

 We have seen OpenCMIS not working in CXF environments. Depending on the 
 classloading, setting the javax.xml.ws.spi.Provider helps in some cases 
 to coexist there. It's not a silver bullet, though.
 I'm not sure auto detection helps here. As a developer I want full 
 control and either I consciously flip a switch or deploy another Jar. 
 Otherwise finding the cause of different behaviors becomes rather 
 difficult. I also have to know which dependency Jars I have to deploy in 
 the first place.

 As I already said, CXF support would be great. I had to work around a 
 lot of RI quirks to make it work for all OpenCMIS scenarios. My gut 
 feeling tells me that CXF is just different and still needs some extra 
 work.


 - Florian





> On Mar 21, 2013, at 7:31 PM, Florian Müller <fmui@apache.org> wrote:
>
>> Hi Oliver,
>>
>> It is not about MTOM and streaming. All JAX-WS frameworks can do 
>> that today. It is about handling SOAP headers. The JAX-WS 
>> specification forces a JAX-WS implementation to load the whole message 
>> (including attachments) in memory when the SOAP headers should be 
>> touched.
>
> Actually, that's not true.   The JAX-WS specification does not
> dictate that.   It dictates that the entire SAAJ model must be
> created, but not that attachments need to be loaded into memory.
> Different JAX-WS stacks do different things with this.   I think the
> RI does resolve the MTOM stuff first which does load it in memory.
> For CXF, the attachments are pulled off the stream, but stored in tmp
> files on disk, not in memory.    The MTOM nodes are left "as is" in
> the SAAJ model.   Thus, you just get the contents of the SOAP part of
> the mime multipart in memory, not the full thing.
>
>> Therefore, the standard way of handling SOAP headers is not feasible 
>> for OpenCMIS. One big document can easily cause an Out Of Memory 
>> exception. That's not a specific problem of a specific JAX-WS 
>> implementation, but a JAX-WS specification problem and therefore all 
>> implementations.
>
> No, not true.   That said, I'd still use the proprietary API's if
> just dealing with application level headers.   For the stuff Oli 
> needs
> related to SAML and security, I'd let the stack handle it the way it
> needs to handle it.
>
>> All JAX-WS implementations have proprietary APIs to work around 
>> that. But if the CXF WS-SecurityPolicies implementation (which I don't 
>> know) uses the standard APIs then you probably will run into memory 
>> issues sooner or later. If you can handle that risk, CXF might work 
>> for you.
>
> For CXF, we CURRENTLY would still need the full SAAJ model (but see
> above about the attachments) for the SOAP part.   We're working on a
> WSS4J 2.0 version that would allow streaming with WS-Security which
> would resolve even that issue.   That's a bit off though.
>
>> You are actually not the first, who wants to make CXF work. See this 
>> mail thread:
>> 
>> http://mail-archives.apache.org/mod_mbox/chemistry-dev/201208.mbox/%3C503E653C.9050903%40apache.org%3E
>>
>> Making it work is not the problem. Making it work without the danger 
>> of a memory issue is difficult.
>
> There is nothing that the RI does to mitigate this that CXF doesn't 
> also do.
>
>> Another reason why CXF is not our first choice is, that its needs 
>> Jars in an endorsed directory. That's a deal-breaker for many projects 
>> that want to use OpenCMIS. Today, OpenCMIS requires Oracles JAX-WS RI 
>> 2.1.7. This is not the latest version of JAX-WS RI for the same 
>> reason. JAX-WS RI 2.2.x also needs Jars in an endorsed directory.
>
> Uhmm…   Another mis-conception.   If we required that, then CXF
> wouldn't work very well for anyone using Maven on Java 6.   :-)
>
> Seriously, CXF does not require anything to be endorsed unless you
> need the 2.2 specific API's and such.   If only the the 2.1 API's are
> found on the classpath and you only use the 2.1 API's, youi are fine.
> The CXF code generator by default does generate 2.2 code (per spec
> requirement).  However, we do have flags to have it generate 2.1
> restricted code.    Most of our examples now set that flag so they
> work "out of the box" without any sort of endorsed jars, even on
> java6.
>
>> I don't want to stop you from making it work. Having CXF support 
>> would be great for OpenCMIS. So, please go ahead and provide a patch. 
>> But I don't see that CXF will become our preferred stack in the 
>> future.
>
> I'm wondering if it would be all possible or preferable to have some
> level of auto detection of which stack is being used after the "new
> XYZService(…)" calls (or after the getXYZPort() calls) and handle the
> various things more automatically.   Right now, if the CXF jars are 
> on
> the classpath prior to the Chemistry one, you would still end up 
> using
> CXF anyway.
>
> Dan
>
>
>
>> - Florian
>>
>>
>>> Hi Florian
>>>
>>> Thanks for the feedback. CXF supports MTOM and streaming 
>>> out-of-the-box without any implementation specific dependencies. I 
>>> think it should by quite easy to integrate CXF as a web services 
>>> stack in chemistry. The security part is then enforced by 
>>> WS-SecurityPolicies without a lot of API usage.
>>>
>>> I'll give it a try. Would you look into this if I raise a JIRA and 
>>> apply a patch including unit testing?
>>>
>>> Are there non resolvable issues do improve performance for the Web 
>>> Services Binding?
>>>
>>> Thanks
>>> Oli
>>>
>>>
>>>
>>> ------
>>>
>>> Oliver Wulff
>>> Blog: http://owulff.blogspot.com
>>>
>>> ________________________________________
>>> From: Florian Müller [fmui@apache.org]
>>> Sent: 21 March 2013 12:38
>>> To: dev@chemistry.apache.org
>>> Cc: Oliver Wulff
>>> Subject: Re: CXF support as web services stack in opencmis
>>>
>>>  Hi Oliver,
>>>
>>>  There is no active development around CXF support at the moment 
>>> (see
>>>  [1] why).
>>>
>>>  But what you want is a custom authentication provider [2]. The 
>>> easiest
>>>  way to build one is to copy the standard authentication provider 
>>> code
>>>  [3] and modify it. We (SAP) have implemented SAML support for our
>>>  infrastructure. So that's doable. WS-Trust STS might be trickier, 
>>> but
>>>  certainly possible.
>>>
>>>  Apart from that, you might want to consider using a different 
>>> binding.
>>>  The Web Services binding is pretty slow compared to the other two
>>>  bindings.
>>>
>>>
>>>  - Florian
>>>
>>>
>>>  [1]
>>>  
>>> http://mail-archives.apache.org/mod_mbox/chemistry-dev/201206.mbox/%3C4FDF8B71.9020108%40apache.org%3E
>>>
>>>  [2]
>>>  
>>> http://chemistry.apache.org/java/developing/client/dev-client-bindings.html#OpenCMISClientBindings-CustomAuthenticationProvider
>>>
>>>  [3]
>>>  
>>> https://svn.apache.org/repos/asf/chemistry/opencmis/trunk/chemistry-opencmis-client/chemistry-opencmis-client-bindings/src/main/java/org/apache/chemistry/opencmis/client/bindings/spi/StandardAuthenticationProvider.java
>>>
>>>
>>>> Hi there
>>>>
>>>>
>>>>
>>>> I'm looking into the usage of opencmis to interact with a CMS 
>>>> system.
>>>> This worked fine with basic security. Currently, username/password 
>>>> is
>>>> supported with HTTP Basic Authentication or WS-Security
>>>> UsernameToken.
>>>> In our case, the CMIS client is deployed in a web application 
>>>> which
>>>> must sent requests on behalf of the web application user. So far, 
>>>> we
>>>> used SAML and the WS-Trust STS which is supported by Apache CXF.
>>>>
>>>>
>>>>
>>>> I've spotted the following class CXFPortProvider but it is not
>>>> active. Is there any other work ongoing in supporting CXF and any
>>>> other WS-Security tokens?
>>>>
>>>>
>>>>
>>>> Thanks
>>>>
>>>> Oli
>>


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