Safeguarding your Virtuoso-hosted SPARQL Endpoint What? Protecting Virtuoso-hosted SPARQL Endpoint.Why? SPARQL endpoints are easy for random visitors to accidentally overload. Virtuoso allows you to secure your SPARQL endpoint against such abuses in various ways.How? The following section should be added to the Virtuoso configuration file (e.g., /opt/virtuoso/database/virtuoso.ini) to safeguard your SPARQL endpoint against excessive usage: [SPARQL] MaxCacheExpiration = 1 ; Cache Expiration time in seconds; overrides Sponger's default cache invalidation scheme ExternalQuerySource = 1 ExternalXsltSource = 1 ResultSetMaxRows = 100000 ;DefaultGraph = http://demo.openlinksw.com/dataspace/person/demo MaxQueryCostEstimationTime = 10000 ; in seconds MaxQueryExecutionTime = 30 ; in seconds ;ImmutableGraphs = http://unknown:8890/dataspace ;PingService = http://rpc.pingthesemanticweb.com/ DefaultQuery = SELECT DISTINCT ?URI ?ObjectType WHERE { ?URI a ?ObjectType } LIMIT 50 DeferInferenceRulesInit = 1 ; Defer loading of inference rules at start up Details about these settings can be found in the SPARQL Configuration File section of the Virtuoso Online Documentation. The "DeferInferenceRulesInit = 1" setting is particularly important when hosting large RDF data sets such as DBpedia, as it defers the load of the inference rules (which can take quite some time -- up to an hour!) until after basic server start-up. Virtuoso Web Services ACLs can also be used to limit access to the SPARQL endpoint. Related SPARQL Endpoint Protection Methods Collection Virtuoso documentation SPARQL Service Endpoint Service Endpoint Security Managing a SPARQL Web Service Endpoint SPARQL Virtuoso Tips and Tricks Collection SPARQL Endpoint DET Configuration Guide WebID Protocol & SPARQL Endpoint ACLs Tutorial SPARQL OAuth Tutorial Securing SPARQL endpoints SPARUL over SPARQL using the http://cname:port/sparql-auth endpoint Virtuoso Authentication Server UI Manage a SPARQL-WebID based Endpoint Configure Virtuoso instance as an X.509 Certificate Authority and HTTPS listener Configure Virtuoso+ODS instance as an X.509 Certificate Authority and HTTPS listener WebID Protocol Support in OpenLink Data Spaces. Manage ODS Datadspaces Objects WebID Access Control Lists (ACLs): ODS Briefcase WebID based ACL Guide Person Entity WebID based ACL Guide Group Entity WebID based ACL Guide Public WebID based ACL Guide ODS Feed Manager WebID based ACL Guide Person Entity Specific ACL Group Entity Specific ACL Public Specific ACL for anyone with a WebID ODS Calendar WebID based ACL Guide Person Entity Specific ACL Group Entity Specific ACL Public Specific ACL for anyone with a WebID ODS Bookmark Manager WebID based ACL Guide Person Entity Specific ACL Group Entity Specific ACL Public Specific ACL for anyone with a WebID ODS Addressbook WebID based ACL Guide Person Entity Specific ACL Group Entity Specific ACL Public Specific ACL for anyone with a WebID Guide for Set up a X.509 certificate issuer and HTTPS listener and generate ODS user certificates. Setting up PubSubHub in ODS PubSubHubBub Demo Client Example Feed subscription via PubSubHub protocol Example Setting Up PubSubHub to use WebID Protocol or IP based control lists CA Keys Import using Conductor Generate an X.509 Certificate hosted WebID Guide Generate an X.509 Certificate (with a WebID watermark) to be managed by host operating system keystore Generate an X.509 Certificate (with a WebID watermark) to be managed by a browser-based keystore Using Virtuoso's WebID Verification Proxy Service with a WebID-bearing X.509 certificate Using Virtuoso's WebID Identity Provider (IdP) Proxy Service with an X.509 certificate ODS Briefcase WebID Protocol Share File Guide WebID Protocol Specification Test WebID Protocol Certificate page WebID Protocol Certificate Generation page CategoryVirtuoso CategoryHowTo CategorySPARQL CategoryOAuth CategoryFOAFSSL CategoryDocumentation CategoryTutorial