Implementation and architecture notes for the Mindquarry Collaboration Server. Presented at the 7th Cocoon GetTogether in Rome.

1. 1
Mindquarry
Mindquarry for
Cocoon Users
Lars Trieloff, Mindquarry

2. What is Mindquarry 2
Mindquarry

3. What is Mindquarry 2
Mindquarry

4. What is Mindquarry 2
Mindquarry

5. What is Mindquarry 2
Mindquarry

6. What is Mindquarry 2
Mindquarry

7. Short Demo 3
Mindquarry Collaboration Server:
Mindquarry
Teams, Files, Tasks and Talk
Mindquarry Desktop Client:
File Synchronization, Task Management
Live Sites:
http://www.mindquarry.org

8. Mindquarry Internals 4
Server based on
Mindquarry
Apache Cocoon 2.2
Apache Jackrabbit
Apache Lucene Solr
Subversion
Apache Web Server
mod_perl
SubethaSMTP
JRuby
Client based on
Java 5
SWT
Svnkit

9. Architecture 5
Jetty Web App Container
Mindquarry

10. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2

11. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Team
Block

12. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Team
Block
Apache Jackrabbit

13. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Team
Block
Apache Jackrabbit
PostgreSQL

14. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Team DForms
Block Block
Apache Jackrabbit
PostgreSQL

15. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki
Block
Team DForms
Block Block
Apache Jackrabbit
PostgreSQL

16. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki Tasks
Block Block
Team DForms
Block Block
Apache Jackrabbit
PostgreSQL

17. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki Tasks
Block Block
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL

18. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki Tasks
Block Block
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

19. Architecture 5
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki Tasks Talk
Block Block Block
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

20. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Apache Cocoon 2.2
Wiki Tasks Talk
Block Block Block
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

21. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Wiki Tasks Talk
Block Block Block
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

22. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Wiki Tasks Talk
Block Block Block REST
Client
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

23. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Wiki Tasks Talk
Block Block Block REST
Client
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

24. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Search Wiki Tasks Talk
Block Block Block Block REST
Client
Team DForms Files
Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

25. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Search Wiki Tasks Talk
Block Block Block Block REST
Client
Solr Team DForms Files
Servlet Block Block Block
Apache Jackrabbit
PostgreSQL SVN Repo

26. Architecture 5
SubethaSMTP
Jetty Web App Container
Mindquarry
Mail Parser
Apache Cocoon 2.2
Search Wiki Tasks Talk
Block Block Block Block REST
Client
Solr Team DForms Files
Lucene
Servlet Block Block Block
Index
Apache Jackrabbit
PostgreSQL SVN Repo

27. Lessons learned 6
Mindquarry
1. Integrating Jackrabbit and Cocoon
2. Using the Servlet Services Architecture
3. Integrating Solr-based search with Cocoon
4. Tuning AJAX Performance
5. Neat REST Tricks in Mindquarry
Code and Libraries available at
www.mindquarry.org

28. Jackrabbit and Cocoon 7
Jackrabbit: JCR/JSR-173 Container
Mindquarry
Versioned, Typed, Queryable Node Store
Ideal for document-centric applications
Mindquarry's Enhancements
com.mindquarry.jcr.xml.source.JCRNodeSource
an JCR-to-XML mapping
com.mindquarry.jcr.jackrabbit.xpath.JaxenQueryHandler
a XPath 1.0 Query handler for Jackrabbit based on Jaxen
Mindquarry's most popular Pitfalls
Having many small nodes in JCR affects performance
Mapping Business objects to JCR is no good idea
There is no easy way to limit the result size of queries

29. Mapping XML to JCR 8
Mindquarry
rep:root
nt:unstructured
/
xt:element xt:text
nt:folder *
nt:folder
STRING xt:characters
users
images
xt:element: child nodes of
type xt:element (XML
elements)
xt:element: child
nt:file properties of type
nt:file STRING (XML attribute)
alex.saar
photo154
nt:unstructured
Binary Data xt:document
xt:document
jcr:content
nt:resource
XML
jcr:content
xt:element
user <user>
BINARY jcr:data
<name>Alexander Saar</name>
<email type=quot;businessquot;>alex@mq.com</name>
STRING jcr:mimeType </user>
xt:element
DATE jcr:lastModified
name
xt:text
text
STRING xt:characters = Alexander Saar
mix:versionable xt:element
email
nt:resource xt:text
Later text
STRING type = business
STRING xt:characters = alex@mq.com
xt:versionableresource

30. Using Servlet Services 9
Servlet Services allow running and interacting with
Mindquarry
arbitrary servlets in the Cocoon quot;Containerquot;
What works great
Shielding: Conflicting dependencies are no problem
Inheritance: Define a parent block that handles all
requests that the child cannot handle
What needs more handwork
Inheritance of resources, e.g. having a common
styling resource for all blocks
Passing complex requests (e.g. including
authentication) between blocks
Polymorphy: e.g. a parent block passing sub-requests
back to the child

31. Mindquarry's Servlet
10
Services
Mindquarry
Solr Tasks
Wiki Block
Servlet Block
Search Team DForms
Files Block Talk Block
Block Block Block
Resources
Usage
Block
Inheritance

32. Integrating Solr and
11
Cocoon
Solr is a REST-based search engine based on Lucene
Mindquarry
Implemented as a Servlet, easy to embed in Cocoon
SolrPost
TextFilter
XSLT
Generator Serializer
HTTP POST XML
Solr AJAX
Lucene
Document
Servlet Client
Index
HTTP
GET
JSON
When using with Jackrabbit, Shielding is neccessary
com.mindquarry.cocoon.TextFilterGenerator

33. Tuning AJAX
12
Performance
Cocoon uses Dojo, which is very powerful
Mindquarry
And up to 500 kb big, which need to be
downloaded
parsed
for every page reload
better use caching
and better do not reload
Mindquarry uses following solution
special AJAX representation of every resource
customization stylesheet (html2lightbox.xsl)
Client side: Dojo widget AjaxLink
replaces every (internal) link with an AJAX call

34. REST in Mindquarry 13
What means REST?
Mindquarry
Everything is a resource and has an URI
Different representations of a resource possible
HTML, XML, RSS, JSON, Atom...
Interaction via GET, PUT, POST, DELETE
HTTP HTTP Session-less
Accept-Headers Authentication web applications

35. HTTP
Accept-Headers 14
Specify what content the client can process
Mindquarry
most often HTML, images, but also XML, JSON, etc.
Definition:
<selector name=quot;RESTquot;
src=quot;org.apache.cocoon.selection.RegexpHeaderSelectorquot;>
<header-name>accept</header-name>
<pattern name=quot;htmlquot;>application/xhtml+xml|text/html|*/*</pattern>
<pattern name=quot;xmlquot;>text/xml</pattern>
<pattern name=quot;atomquot;>application/atom.xml</pattern>
<pattern name=quot;pdfquot;>application/pdf</pattern>
<pattern name=quot;opmlquot;>text/x-opml</pattern>
<pattern name=quot;icalquot;>text/calendar</pattern>
<pattern name=quot;jsonquot;>(text|application)/json</pattern>
</selector>

36. HTTP
Accept-Headers 15
Usage Example:
Mindquarry
<select type=quot;RESTquot;>
<when test=quot;jsonquot;>
<transform src=quot;xslt/json/log2jsonXML.xslquot;>
<parameter name=quot;baselinkquot; value=quot;/tasks/{1}/{2}quot; />
</transform>
<transform type=quot;i18nquot;>
<parameter name=quot;localequot; value=quot;{request-attr:locale}quot; />
<parameter name=quot;default-catalogue-idquot; value=quot;mindquarryquot; />
</transform>
<serialize type=quot;jsonquot; />
</when>
<otherwise>
<serialize type=quot;xmlquot; />
</otherwise>
</select>

37. HTTP
Accept-Headers 16
What to do if my client does not support Accept-
Mindquarry
Headers?
<filter>
<filter-name>HttpHeaderSpoofingFilter</filter-name>
<display-name>HTTP Header Spoofing Filter</display-name>
<filter-class>
com.mindquarry.webapp.servlet.HttpHeaderSpoofingFilter
</filter-class>
</filter>
Turns http-*-header request parameters into actual
HTTP headers
Example usage
http://localhost:8888/changes?http-accept-
header=application/json

38. HTTP
Authentication 17
HTTP-Basic or HTTP-Digest Authentication
Mindquarry
cross client support (even non-interactive)
no Cookies needed
no Sessions needed
But: ugly login window

39. HTTP
Authentication 18
Mindquarry
Mindquarry's solution combines
a servlet filter
a Dojo (AJAX) widget
<filter>
<filter-name>MindquarryAuthenticationFilter</filter-name>
<display-name>
Mindquarry Authentication filter
</display-name>
<filter-class>
com.mindquarry.user.webapp.AuthenticationFilter
</filter-class>
<init-param>
<param-name>realm</param-name>
<param-value>Mindquarry Server</param-value>
</init-param>
</filter>

40. Session-less
web applications 19
Mindquarry
Mindquarry needs no sessions
REST architecture
HTTP Authentication
Easy to cluster
But Mindquarry uses CForms, which uses
Continuations, which is very close to sessions
A better solution:
AJAX-based forms
construct XML document from form values
send PUT, POST or DELETE afterwards
But not yet implemented

41. 20
Mindquarry
Thank You
www.mindquarry.com
lars.trieloff@mindquarry.com