modules/clients/src/test/java/org/apache/ignite/internal/client/ClientReconnectionSelfTest.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.ignite.internal.client;

import java.nio.channels.ClosedChannelException;
import java.util.ArrayList;
import java.util.Collection;
import org.apache.ignite.IgniteCheckedException;
import org.apache.ignite.internal.client.impl.connection.GridClientConnectionResetException;
import org.apache.ignite.internal.util.typedef.X;
import org.apache.ignite.testframework.junits.common.GridCommonAbstractTest;
import org.junit.Ignore;
import org.junit.Test;

import static org.apache.ignite.internal.client.ClientTestRestServer.FIRST_SERVER_PORT;
import static org.apache.ignite.internal.client.ClientTestRestServer.SERVERS_CNT;

/**
 *
 */
public class ClientReconnectionSelfTest extends GridCommonAbstractTest {
    /** */
    public static final String HOST = "127.0.0.1";

    /** */
    private ClientTestRestServer[] srvs = new ClientTestRestServer[SERVERS_CNT];

    /** {@inheritDoc} */
    @Override protected void afterTest() throws Exception {
        for (int i = 0; i < srvs.length; i++) {
            ClientTestRestServer srv = srvs[i];

            if (srv != null)
                srv.stop();

            srvs[i] = null;
        }

        super.afterTest();
    }

    /**
     * @return Client for test.
     * @throws GridClientException In case of error.
     */
    private GridClient client() throws GridClientException {
        return client(HOST);
    }

    /**
     * @param host - server host
     * @return Client for test.
     * @throws GridClientException In case of error.
     */
    private GridClient client(String host) throws GridClientException {
        GridClientConfiguration cfg = new GridClientConfiguration();

        cfg.setProtocol(GridClientProtocol.TCP);

        Collection<String> addrs = new ArrayList<>();

        for (int port = FIRST_SERVER_PORT; port < FIRST_SERVER_PORT + SERVERS_CNT; port++)
            addrs.add(host + ":" + port);

        cfg.setServers(addrs);

        cfg.setTopologyRefreshFrequency(60 * 60 * 1000);

        return GridClientFactory.start(cfg);
    }

    /**
     * @throws Exception If failed.
     */
    @Test
    public void testNoFailedReconnection() throws Exception {
        for (int i = 0; i < SERVERS_CNT; i++)
            runServer(i, false);

        try (GridClient client = client()) { // Here client opens initial connection and fetches topology.
            // Only first server in list should be contacted.
            assertEquals(1, srvs[0].getConnectCount());

            for (int i = 1; i < SERVERS_CNT; i++)
                assertEquals(0, srvs[i].getConnectCount());

            srvs[0].resetCounters();

            int contactedSrv = 0;

            for (int i = 0; i < 100; i++) {
                int failed = contactedSrv;

                srvs[failed].fail();

                // Sometimes session close missing on client side. Retry few times until request succeeds.
                while (true)
                    try {
                        client.compute().refreshTopology(false, false);

                        break;
                    }
                    catch (GridClientConnectionResetException e) {
                        info("Exception caught: " + e);
                    }

                // Check which servers where contacted,
                int connects = 0;

                for (int srv = 0; srv < SERVERS_CNT; srv++) {
                    if (srvs[srv].getSuccessfulConnectCount() > 0) {
                        assertTrue("Failed server was contacted: " + srv, srv != failed);

                        contactedSrv = srv;
                    }

                    connects += srvs[srv].getSuccessfulConnectCount();
                }

                assertEquals(1, connects); // Only one new connection should be opened.

                srvs[failed].repair();

                srvs[contactedSrv].resetCounters(); // It should be the only server with non-0 counters.
            }

        }
    }

    /**
     * @throws Exception If failed.
     */
    @Test
    public void testCorrectInit() throws Exception {
        for (int i = 0; i < SERVERS_CNT; i++)
            runServer(i, i == 0);

        try (GridClient ignored = client()) { // Here client opens initial connection and fetches topology.
            // First and second should be contacted, due to failure in initial request to the first.
            for (int i = 0; i < 2; i++)
                assertEquals("Iteration: " + i, 1, srvs[i].getConnectCount());

            for (int i = 2; i < SERVERS_CNT; i++)
                assertEquals(0, srvs[i].getConnectCount());
        }
    }

    /**
     * @throws Exception If failed.
     */
    @Test
    public void testFailedInit() throws Exception {
        for (int i = 0; i < SERVERS_CNT; i++)
            runServer(i, true);

        GridClient c = client();

        try {
            c.compute().execute("fake", "arg");

            fail("Client operation should fail when server resets connections.");
        }
        catch (GridClientDisconnectedException e) {
            assertTrue("Thrown exception doesn't have an expected cause: " + X.getFullStackTrace(e),
                X.hasCause(e, GridClientConnectionResetException.class, ClosedChannelException.class));
        }

        for (int i = 0; i < SERVERS_CNT; i++)
            // Connection manager does 3 attempts to get topology before failure.
            assertEquals("Server: " + i, 3, srvs[i].getConnectCount());
    }

    /**
     * TODO: IGNITE-590.
     *
     * @throws Exception If failed.
     */
    @Ignore("https://issues.apache.org/jira/browse/IGNITE-590")
    @Test
    public void testIdleConnection() throws Exception {
        int srvsCnt = 4; // TODO: IGNITE-590 it may be wrong value. Need to investigate after IGNITE-590 will be fixed.

        for (int i = 0; i < srvsCnt; i++)
            runServer(i, false);

        GridClient client = client(); // Here client opens initial connection and fetches topology.

        try {
            // Only first server in list should be contacted.
            assertEquals(1, srvs[0].getConnectCount());

            Thread.sleep(35000); // Timeout as idle.

            assertEquals(1, srvs[0].getDisconnectCount());

            for (int i = 1; i < srvsCnt; i++)
                assertEquals(0, srvs[i].getConnectCount());

            srvs[0].resetCounters();

            // On new request connection should be re-opened.
            client.compute().refreshTopology(false, false);

            assertEquals(1, srvs[0].getConnectCount());

            for (int i = 1; i < srvsCnt; i++)
                assertEquals(0, srvs[i].getConnectCount());
        }
        finally {
            GridClientFactory.stop(client.id());
        }
    }

    /**
     * Runs a new server with given index.
     *
     * @param idx Server index, same as in client configuration's servers property.
     * @param failOnConnect If {@code true} the server should fail incoming connection immediately.
     * @return Server instance.
     * @throws IgniteCheckedException If failed.
     */
    private ClientTestRestServer runServer(int idx, boolean failOnConnect) throws IgniteCheckedException {
        ClientTestRestServer srv = new ClientTestRestServer(FIRST_SERVER_PORT + idx, failOnConnect, log());

        srv.start();

        srvs[idx] = srv;

        return srv;
    }
}