NamespaceIsolationPolicy.java

/**
 * Copyright 2016 Yahoo Inc.
 *
 * 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.yahoo.pulsar.common.policies;

import java.net.URL;
import java.util.List;
import java.util.SortedSet;

import com.yahoo.pulsar.common.naming.NamespaceName;
import com.yahoo.pulsar.common.policies.data.BrokerStatus;

public interface NamespaceIsolationPolicy {

    /**
     * Get the list of regex for the set of primary brokers
     *
     * @return
     */
    List<String> getPrimaryBrokers();

    /**
     * Get the list of regex for the set of secondary brokers
     *
     * @return
     */
    List<String> getSecondaryBrokers();

    /**
     * Get the list of primary brokers for the namespace according to the policy
     *
     * @param availableBrokers
     * @param namespace
     * @return
     */
    List<URL> findPrimaryBrokers(List<URL> availableBrokers, NamespaceName namespace);

    /**
     * Get the list of secondary brokers for the namespace according to the policy
     *
     * @param availableBrokers
     * @param namespace
     * @return
     */
    List<URL> findSecondaryBrokers(List<URL> availableBrokers, NamespaceName namespace);

    /**
     * Check to see whether the primary brokers can still handle a new namespace or has to failover
     *
     * @param primaryCandidates
     * @return
     */
    boolean shouldFailover(SortedSet<BrokerStatus> primaryCandidates);

    /**
     * Check to see whether the primary brokers can still handle a new namespace or has to failover
     *
     * @param totalPrimaryCandidates
     * @return
     */
    boolean shouldFailover(int totalPrimaryCandidates);

    /**
     * Check to see whether the namespace ownership should fallback to the primary brokers
     *
     * @param primaryBrokers
     * @return
     */
    boolean shouldFallback(SortedSet<BrokerStatus> primaryBrokers);

    /**
     * Check to see whether the specific host is a primary broker
     *
     * @param brokerAddress
     * @return
     */
    boolean isPrimaryBroker(String brokerAddress);

    /**
     * Check to see whether the specific host is a secondary broker
     *
     * @param brokerAddress
     * @return
     */
    boolean isSecondaryBroker(String brokerAddress);

    /**
     * According to the namespace isolation policy, find the allowed available primary brokers
     *
     * @param primaryCandidates
     * @return
     */
    SortedSet<BrokerStatus> getAvailablePrimaryBrokers(SortedSet<BrokerStatus> primaryCandidates);

    boolean isPrimaryBrokerAvailable(BrokerStatus brkStatus);
}