topic Re: CMIS Query length limited to 7884 characters? in Alfresco Archive

CMIS Query length limited to 7884 characters?

geert — Wed, 15 Jun 2011 15:08:22 GMT

Hi all,We are working on a project using CMIS 0.3.0 to connect to an Alfresco 3.4.0 repository.We noticed that when executing a query longer than 7884 characters an exception occurs. The server side (CMIS @ Alfresco) shows the following stack tracerg.springframework.extensions.webscripts.WebScript

Re: CMIS Query length limited to 7884 characters?

geert — Thu, 16 Jun 2011 07:18:27 GMT

Thanks to a mailing list reply from Florian, we were able to fix it!

On 15 Jun 2011, at 18:00, Florian Müller wrote:

> Hi Mano,
>
> It's not an OpenCMIS issues, but it is not Alfresco specific either. All Tomcat based CMIS repositories have this issue and it may affect other HTTP servers as well.
>
> The CMIS specification says that the server has to add a Location header to its query response that is "representing the feed for that query". That basically means that the query is repeated in the HTTP header.
> The default header buffer size in Tomcat 6 and 7 is 8k. If you remove all other headers you end up with about 7884 byte – plus/minus a few bytes.
> You can increase header buffer size in Tomcat. See [1].
>
> Florian
>
>
> [1] http://tomcat.apache.org/tomcat-6.0-doc/config/http.html#Standard_Implementation -> maxHttpHeaderSize

Re: CMIS Query length limited to 7884 characters?

stefan776 — Wed, 27 Jul 2011 00:30:52 GMT

Thanks for the tip, that got me on the right track.
I ran into the same problem when trying to execute a ~13k long CMIS query (don't ask…), so I decided to bump up it up to 20k.

Since my Tomcat server is only indirectly accessible through Apache (via mod_proxy_ajp), there were some extra measures that had to be taken in order to get this to work.

1. Set the packetSize attribute for your AJP Connector.

<Connector port="8009" protocol="AJP/1.3" redirectPort="8443" tomcatAuthentication="false" enableLookups="false" packetSize="20480"/>‍

2. In your Apache configuration, set the LimitRequestFieldSize and ProxyIOBufferSize directives to a corresponding value


LimitRequestFieldSize 20480
ProxyIOBufferSize 20480
‍‍‍‍

Hope this helps!