LoadDistributorTest.java

/**
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements. See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership. The ASF licenses this file
 * to you 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 org.apache.cxf.systest.clustering;

import java.util.HashMap;
import java.util.Map;
import javax.xml.ws.WebServiceException;
import org.apache.cxf.clustering.LoadDistributorTargetSelector;
import org.apache.cxf.endpoint.ConduitSelector;
import org.apache.cxf.frontend.ClientProxy;
import org.junit.Test;


/**
 * Tests load distribution within a static cluster.
 */
public class LoadDistributorTest extends FailoverTest {

    private static final String FAILOVER_CONFIG =
        "org/apache/cxf/systest/clustering/load_distributor.xml";

    protected String getConfig() {
        return FAILOVER_CONFIG;
    }

    private String responseFrom(String response) {
        if (response.endsWith(REPLICA_A)) {
            return REPLICA_A;
        } else if (response.endsWith(REPLICA_B)) {
            return REPLICA_B;
        } else if (response.endsWith(REPLICA_C)) {
            return REPLICA_C;
        } else if (response.endsWith(REPLICA_E)) {
            return REPLICA_E;
        } else {
            return response;
        }
    }

    private void incrementResponseCount(Map< String, Integer > responseCounts,
                                        String response) {
        String responder = responseFrom(response);
        Integer currentCount = responseCounts.get(responder);
        responseCounts.put(responder, 1 + (currentCount == null ? 0 : currentCount));
    }

    /*
     * This test can't be left to super because the distributor ignores the default
     * endpoint, so we need to get REPLICA_A added to the list of endpoints.
     */
    @Test
    @Override
    public void testRevertExceptionOnUnsucessfulFailover() throws Exception {
        targets.add(REPLICA_A);
        super.testRevertExceptionOnUnsucessfulFailover();

    }

    @Test
    public void testDistributedSequentialStrategy() throws Exception {
        startTarget(REPLICA_A);
        startTarget(REPLICA_B);
        startTarget(REPLICA_C);
        startTarget(REPLICA_E);
        setupGreeter();

        // Change the strategy to iterate through the endpoints
        ConduitSelector conduitSelector =
            ClientProxy.getClient(greeter).getConduitSelector();
        if (conduitSelector instanceof LoadDistributorTargetSelector) {
            ((LoadDistributorTargetSelector)conduitSelector).setStrategy(
                    new LoadDistributorStaticStrategy());
        } else {
            fail("unexpected conduit selector: " + conduitSelector);
        }


        Map< String, Integer > responseCounts = new HashMap<>();
        for (int i = 0; i < 12; ++i) {
            String response = greeter.greetMe("fred");
            assertNotNull("expected non-null response", response);
            incrementResponseCount(responseCounts, response);
        }
        assertEquals(3, (long)responseCounts.get(REPLICA_A));
        assertEquals(3, (long)responseCounts.get(REPLICA_B));
        assertEquals(3, (long)responseCounts.get(REPLICA_C));
        assertEquals(3, (long)responseCounts.get(REPLICA_E));
        stopTarget(REPLICA_A);
        stopTarget(REPLICA_B);
        stopTarget(REPLICA_C);
        stopTarget(REPLICA_E);
    }

    @Test
    public void testDistributedSequentialStrategyWithFailover() throws Exception {
        startTarget(REPLICA_A);
        startTarget(REPLICA_B);
        startTarget(REPLICA_C);
        setupGreeter();
        stopTarget(REPLICA_B);
        ConduitSelector conduitSelector =
            ClientProxy.getClient(greeter).getConduitSelector();
        if (conduitSelector instanceof LoadDistributorTargetSelector) {
            ((LoadDistributorTargetSelector)conduitSelector).setStrategy(
                    new LoadDistributorStaticStrategy());
        } else {
            fail("unexpected conduit selector: " + conduitSelector);
        }
        Map< String, Integer > responseCounts = new HashMap<>();
        for (int i = 0; i < 12; ++i) {
            String response = greeter.greetMe("fred");
            assertNotNull("expected non-null response", response);
            incrementResponseCount(responseCounts, response);
        }
        assertTrue((long)responseCounts.get(REPLICA_A) > 0);
        assertTrue((long)responseCounts.get(REPLICA_C) > 0);
        assertEquals(12, responseCounts.get(REPLICA_A) + responseCounts.get(REPLICA_C));
        stopTarget(REPLICA_A);
        stopTarget(REPLICA_C);
    }

    @Test
    public void testDistributedSequentialStrategyWithoutFailover() throws Exception {
        startTarget(REPLICA_A);
        startTarget(REPLICA_B);
        startTarget(REPLICA_C);
        startTarget(REPLICA_E);
        setupGreeter();
        stopTarget(REPLICA_B);
        ConduitSelector conduitSelector =
            ClientProxy.getClient(greeter).getConduitSelector();
        if (conduitSelector instanceof LoadDistributorTargetSelector) {
            ((LoadDistributorTargetSelector)conduitSelector).setStrategy(
                    new LoadDistributorStaticStrategy());
            ((LoadDistributorTargetSelector)conduitSelector).setFailover(false);
        } else {
            fail("unexpected conduit selector: " + conduitSelector);
        }

        Map< String, Integer > responseCounts = new HashMap<>();
        for (int i = 0; i < 12; ++i) {
            try {
                String response = greeter.greetMe("fred");
                assertNotNull("expected non-null response", response);
                incrementResponseCount(responseCounts, response);
            } catch (WebServiceException ex) {
                incrementResponseCount(responseCounts, "");
            }
        }
        assertEquals(3, (long)responseCounts.get(REPLICA_A));
        assertEquals(null, responseCounts.get(REPLICA_B));
        assertEquals(3, (long)responseCounts.get(REPLICA_C));
        assertEquals(3, (long)responseCounts.get(REPLICA_E));
        assertEquals(3, (long)responseCounts.get(""));
        stopTarget(REPLICA_A);
        stopTarget(REPLICA_C);
        stopTarget(REPLICA_E);
    }


}