是否可以在进程中启动 Zookeeper 服务器实例，例如用于单元测试？

Question

调用 org.apache.zookeeper.server.quorum.QuorumPeerMain.main() 不起作用。

Answer 1

Netfix 开源 Curator 一个可以使用的框架Zookeeper就更方便了。它内置了测试服务器类。只需将此测试依赖项添加到您的项目描述符中，无论是 maven、gradle 还是其他：

org.apache.curator:curator-framework:4.0.1
org.apache.curator:curator-test:4.0.1

以下是测试要点。

TestingServer zkTestServer;
CuratorFramework cli;

@Before
public void startZookeeper() throws Exception {
    zkTestServer = new TestingServer(2181);
    cli = CuratorFrameworkFactory.newClient(zkTestServer.getConnectString(), new RetryOneTime(2000));
    cli.start();
}

@After
public void stopZookeeper() throws IOException {
    cli.close();
    zkTestServer.stop();
}

使用 cli 创建任何测试数据都非常容易（需要 curator-framework 依赖项）。

cli.create()
   .creatingParentsIfNeeded()
   .forPath("/a1", "testvalue".getBytes("UTF-8"));

Answer 2

要启动 ZooKeeper，您必须执行 ZooKeeperServerMain 类。

您可以使用以下代码以嵌入模式启动 ZooKeeper。

Properties startupProperties = ...

QuorumPeerConfig quorumConfiguration = new QuorumPeerConfig();
try {
    quorumConfiguration.parseProperties(startupProperties);
} catch(Exception e) {
    throw new RuntimeException(e);
}

zooKeeperServer = new ZooKeeperServerMain();
final ServerConfig configuration = new ServerConfig();
configuration.readFrom(quorumConfiguration);

new Thread() {
    public void run() {
        try {
            zooKeeperServer.runFromConfig(configuration);
        } catch (IOException e) {
            log.error("ZooKeeper Failed", e);
        }
    }
}.start();

Answer 3

你可以使用这样的东西。

int clientPort = 21818; // none-standard
int numConnections = 5000;
int tickTime = 2000;
String dataDirectory = System.getProperty("java.io.tmpdir");

File dir = new File(dataDirectory, "zookeeper").getAbsoluteFile();

ZooKeeperServer server = new ZooKeeperServer(dir, dir, tickTime);
NIOServerCnxn.Factory standaloneServerFactory = new NIOServerCnxn.Factory(new InetSocketAddress(clientPort), numConnections);

standaloneServerFactory.startup(server); // start the server.

要关闭它，只需调用standaloneServerFactory.shutdown()

Answer 4

通过添加临时端口的使用（由 zkPort 所示），以 1 的答案为基础并更新了最新的 ZK API：

int tickTime = 2000;
int numConnections = 5000;
String dataDirectory = System.getProperty("java.io.tmpdir");

File dir = new File(dataDirectory, "zookeeper").getAbsoluteFile();

ZooKeeperServer server = new ZooKeeperServer(dir, dir, tickTime);
standaloneServerFactory = ServerCnxnFactory.createFactory(0, numConnections);
int zkPort = standaloneServerFactory.getLocalPort();

standaloneServerFactory.startup(server);

Answer 5

ServerConfig config = new ServerConfig();
config.parse(new String[] {port, dir});
ZooKeeperServerMain zk = new ZooKeeperServerMain();
zk.runFromConfig(config);

Answer 6

GeoffBourne 答案的更新版本。

    int clientPort = 2199; // not standard
    int numConnections = 5000;
    int tickTime = 2000;
    String dataDirectory = System.getProperty("java.io.tmpdir");

    File dir = new File(dataDirectory, "zookeeper").getAbsoluteFile();

    ZooKeeperServer server = new ZooKeeperServer(dir, dir, tickTime);
    ServerCnxnFactory factory = new NIOServerCnxnFactory();
    factory.configure(new InetSocketAddress(clientPort), numConnections);

    factory.startup(server); // start the server.

    // ...shutdown some time later
    factory.shutdown();