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1. OpenSSH client - port forwarding
   connect to DSpace server and forward its port 8080 to localhost (machine we're connecting from) port 1234

   Code Block
   ssh -L 1234:127.0.0.1:8080 mydspace.edu

   makes mydspace.edu:8080 accessible via localhost:1234 (type http://localhost:1234 in browser address bar) Code Blockssh -L 1234:127.0.0.1:8080 mydspace.edu; also opens ssh shell
   exit ssh to terminate port forwarding
   Alternatively:

   Code Block
   ssh -N -f -L 1234:127.0.0.1:8080 mydspace.edu

   run with -N and -f flags if you want ssh to go to background;
   kill the ssh process to terminate port forwarding
2. Putty client - port forwarding
   The same with Putty:

   Code Block
   Connection - SSH - Tunnels Source port: 8080 Destination: localhost:1234 Local Auto Add

3. OpenSSH client - SOCKS proxy
   connect to DSpace server and run a SOCKS proxy server on localhost port 1234; configure browser to use localhost:1234 as SOCKS proxy and remove "localhost" and "127.0.0.1" from addresses that bypass this proxy
   all browser requests now originate from dspace server (source IP is dspace server's IP) - dspace is the proxy server
   type http://localhost:8080 in browser address bar - localhost here is the dspace server

   Code Block
   ssh -D 1234 mydspace.edu

Note about Putty as SOCKS proxy - while it can be configured, it raises a security exception when Solr is accessed. If you figure this out, please add this method here.

Accessing Solr

Solr cores

DSpace contains a so-called multicore installation of Solr. That means that there are multiple Solr indexes and configurations sharing one Solr codebase. If you're familiar with Apache HTTPD, it is analogous to multiple virtual hosts running on one Apache server (separate configuration and webpages), except that individual Solr cores are accessible via different URL (as opposed to virtualhost IP:port).

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Note:
facet.field=epersonid — You want to group by epersonid, which is the user id.
type:0 — Interested in bitstreams only

Querying Solr from XMLUI

Since Solr returns its responses in XML, it's possible and easy to call custom Solr queries from XMLUI, process the XML response with XSLT and display the results in human-readable form on the HTML page.
There are two ways how to do that - synchronously in Cocoon or asynchronously using AJAX (JavaScript) after the page is loaded. Solr queries are usually very fast, so only synchronous calls will be shown here.

You can include another XML document to be processed by XSLT using the document() function. The parameter to this function is an XML document to process. This can be either a static .xml file stored on the server or a URL, which will be fetched at time of processing. For Solr, the latter is what we need. Furthermore, we need to distinguish templates for processing this external XML document as opposed to the input XML document. We'll do this using the mode attribute.

<xsl:apply-templates select="document('http://localhost:8080/select?q=search.resourcetype:2&amp;sort=dc.date.accessioned_dt%20desc&amp;rows=1&amp;fl=dc.date.accessioned_dt&amp;omitHeader=true'))"
mode="solr-response"/>

Now we need to define a template with the same mode that matches elements contained in the Solr response XML:

<xsl:template match="/response/result/doc/date" mode="solr-response">
    Last item was imported: <xsl:value-of select="text()"/>
</xsl:template>

Furthermore, we don't want to hardcode the http://localhost:8080Image Added Solr URL, because this can be changed in config file and it would break the template. So we'll call a Java function from XSLT to retrieve the configured Solr URL. See the complete example in the next section.

Examples

Date of last deposited item

For description of the query parameters, see above.

1. Add confman namespace and "confman" to exclude-result-prefixes.

   Code Block
   XML XML
   <xsl:stylesheet ... xmlns:confman="org.dspace.core.ConfigurationManager" exclude-result-prefixes="... confman">

2. Add this simple template to process Solr result. More complex date formatting can be done easily in XSLT 2.0 (see XSLT 2.0 spec), however Cocoon still uses XSLT 1.0 (see DS-995). It is currently also possible to call Java functions to do date formatting.

   Code Block
   XML XML
   <xsl:template match="/response/result/doc/date" mode="lastItem"> Last item was imported: <xsl:value-of select="substring(text(), 1, 10)"/> </xsl:template>

3. Add the following code to the place where you want the resulting text to appear:

   Code Block
   XML XML
   <xsl:variable name="solr-search-url" select="confman:getProperty('discovery', 'search.server')"/> <xsl:apply-templates select="document(concat($solr-search-url, '/select?q=search.resourcetype:2&amp;sort=dc.date.accessioned_dt%20desc&amp;rows=1&amp;fl=dc.date.accessioned_dt&amp;omitHeader=true'))" mode="lastItem"/>

   For example, to add it after the list of Recent items in Mirage, override its template like this:

   Code Block
   XML XML
   <xsl:template match="dri:referenceSet[@type = 'summaryList' and @n='site-last-submitted']" priority="2"> <xsl:apply-templates select="dri:head"/> <!-- Here we decide whether we have a hierarchical list or a flat one --> <xsl:choose> <xsl:when test="descendant-or-self::dri:referenceSet/@rend='hierarchy' or ancestor::dri:referenceSet/@rend='hierarchy'"> <ul> <xsl:apply-templates select="*[not(name()='head')]" mode="summaryList"/> </ul> </xsl:when> <xsl:otherwise> <ul class="ds-artifact-list"> <xsl:apply-templates select="*[not(name()='head')]" mode="summaryList"/> </ul> </xsl:otherwise> </xsl:choose> <xsl:variable name="solr-search-url" select="confman:getProperty('discovery', 'search.server')"/> <xsl:apply-templates select="document(concat($solr-search-url, '/select?q=search.resourcetype:2&amp;sort=dc.date.accessioned_dt%20desc&amp;rows=1&amp;fl=dc.date.accessioned_dt&amp;omitHeader=true'))" mode="lastItem"/> </xsl:template>

Guidepost

Other pages on this wiki describing Solr and Discovery.

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