/*
* Copyright (c) 2008-2017, Hazelcast, Inc. All Rights Reserved.
*
* Licensed under the Apache License, Version 2.0 (the "License");
* you may not use this file except in compliance with the License.
* You may obtain a copy of the License at
*
* http://www.apache.org/licenses/LICENSE-2.0
*
* Unless required by applicable law or agreed to in writing, software
* distributed under the License is distributed on an "AS IS" BASIS,
* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
* See the License for the specific language governing permissions and
* limitations under the License.
*/
package com.hazelcast.spi.discovery;
/**
* The NodeFilter, if supplied, will retrieve all discovered nodes and might
* apply additional filtering based on vendor provided metadata. These metadata
* are expected to be provided using the {@link DiscoveryNode#getProperties()}
* method and may contain additional information initially setup by the user.
* <p/>
* This is useful for additional security settings, to apply a certain type of
* policy or to work around insufficient query languages of cloud providers.
* <p/>
* Denied {@link DiscoveryNode}s will not be
* handed over to the Hazelcast connection framework and therefore are not
* known to the discovered.
*
* @since 3.6
*/
public interface NodeFilter {
/**
* Accepts or denies a {@link DiscoveryNode}
* based on the implemented rules.
*
* @param candidate the candidate to be tested
* @return true if the DiscoveryNode is selected to be discovered, otherwise false.
*/
boolean test(DiscoveryNode candidate);
}