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The saml-md-aggregator is based on Spring 3. It uses a RESTful URL model and relies on the JAVA cryptography engine for key management and PKCS#11 as an interface to Hardware Security Modules (HSMs). In order to provide fast searching and lookup based on tags on metadata the saml-md-aggregator employs a graph database called neo4j. The neo4j database is non-essential - if doesn't store critical data and is only used as an index. If things break, just delete the database and it will get re-created on next restart.
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