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 <[email protected]> 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 [[email protected]]
Sent: 21 March 2013 12:38
To: [email protected]
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
