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h1. Federated Query Processor 1.4 Administrators Guide

h1. Obtaining the Service
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The Federated Query Processor service is available in the caGrid release, and can be found in the directory $CAGRID_LOCATION/projects/fqp. If you have obtained a source release or checkout of caGrid, the FQP service must first be complied. From the directory $CAGRID_LOCATION, execute the command *ant all* to compile all of caGrid including the FQP service, or *ant build-project \-Dsingle.project.name=fqp* to build just the FQP service and the projects on which it depends.

The Federated Query Processor service may be configured by changing values specified in the service.properties file found in the root directory of the FQP distribution.

* *maxTargetServicesPerQuery*
** Default value: 12
** Type: Integer
** Controls the maximum number of target data services which may be included in any single DCQL query. If a client attempts to execute a query which specifies more than this number of target data services, an exception will be thrown and the query will not execute. If this value is set to zero (0), the number of services is unlimited.
* *maxRetryTimeout*
** Default value: 300
** Type: Integer
** Controls the maximum number of seconds a client may request the FQP service to wait between retrying queries to target data services which failed to respond correctly. If the client specifies a value greater than this, an exception will be thrown and the query will not execute. If this value is set to zero (0), the maximum timeout is unlimited.
* *maxRetries*
** Default value: 4
** Type: Integer
** Controls the maximum number of retries a client may request the FQP service to perform when retrying to execute queries to target data services which failed to respond correctly. If the client specifies a value greater than this, an exception will be thrown and the query will not execute. If this value is set to zero (0), the maximum number of retries is unlimited.
* *threadPoolSize*

h2. Edit Service Metadata

FQP provides service metadata to clients and other services that describes information about the service, operations supported by the service, and information on the organization hosting the service.

Edit the service metadata to reflect your organization as follows:

# Open the FQP service metadata file, *{_}FQP_HOME/etc/serviceMetadata.xml{_}*.
# In the *{_}hostingResearchCenter{_}* element near the bottom of the file, do the following.
## Supply your *ResearchCenter* infomation.
## Supply your *Address*. This is the address that is used when mapping your service on the caGrid Portal.

<ns53:pointOfContactCollection>
<ns53:PointOfContact affiliation="OSU" email="John.Doe@osumc.edu" firstName="John" lastName="Doe" phoneNumber="(555) 555-5555" role="Maintainer"/>
</ns53:pointOfContactCollection>
</ns53:ResearchCenter>

import gov.nih.nci.cagrid.fqp.client.FederatedQueryProcessorClient;

import java.io.FileReader;
import java.io.StringWriter;

public class SimpleFQP {

public static void main(String[] args) {
String url = args[0];
String queryFile = args[1];

try {
FederatedQueryProcessorClient client =
new FederatedQueryProcessorClient(url);
FileReader reader = new FileReader(queryFile);
DCQLQuery query = (DCQLQuery) Utils.deserializeObject(
reader, DCQLQuery.class);
reader.close();
System.out.println("Querying " + url);
DCQLQueryResultsCollection results = client.execute(query);
StringWriter writer = new StringWriter();
Utils.serializeObject(
results,
DCQLQueryResultsCollection.getTypeDesc().getXmlType(),
writer);
System.out.println(writer.getBuffer().toString());
System.out.println("Done");
} catch (Exception ex) {
ex.printStackTrace();
System.exit(1);
}

</ns1:TargetObject>

<ns2:ObjectResult>
<ns2:Publication id="1" authors="Calvo A, Xiao N, Kang J, Best CJ, Leiva I, Emmert-Buck MR, Jorcyk C, Green JE" pages="5325-35" publication="Cancer Research" pubMedId="12235003" title="Alterations in gene expression profiles during prostate cancer progression" uri="http://cancerres.aacrjournals.org/cgi/content/full/62/18/5325" volume="62" year="2002" xmlns:ns2="gme://caArray.caBIG/2.1/gov.nih.nci.caarray.domain.publication">
<ns2:status>
<ns3:Term id="680" value="Published" xmlns:ns3="gme://caArray.caBIG/2.1/gov.nih.nci.caarray.domain.vocabulary">
<ns3:categories/>
</ns3:Term>
</ns2:status>
</ns2:Publication>
</ns2:ObjectResult>
<ns2:ObjectResult>
<ns4:Publication id="10" authors="Rygaard K, Sorenson GD, Pettengill OS, Cate CC, Spang-Thomsen M." pages="5312-5317" publication="Cancer Research" pubMedId="2167152" title="Abnormalities in structure and expression of the retinoblastoma gene in small cell lung cancer cell lines and xenografts in nude mice" volume="50" year="1990" xmlns:ns4="gme://caArray.caBIG/2.1/gov.nih.nci.caarray.domain.publication">
<ns4:status>
<ns5:Term id="680" value="Published" xmlns:ns5="gme://caArray.caBIG/2.1/gov.nih.nci.caarray.domain.vocabulary">
<ns5:categories/>
</ns5:Term>
</ns4:status>
<ns4:type>
<ns6:Term id="47" accession="MO_430" url="http://mged.sourceforge.net/ontologies/MGEDontology.php#journal_article" value="journal_article" xmlns:ns6="gme://caArray.caBIG/2.1/gov.nih.nci.caarray.domain.vocabulary">
<ns6:categories/>
</ns6:Term>
</ns4:type>
</ns4:Publication>
</ns2:ObjectResult>
</ns2:CQLQueryResultCollection>
</ns1:DCQLResult>
</ns1:DCQLQueryResultsCollection>
{code}