ZooKeeper源码(2)cli,client,common,jmx,version包

最新推荐文章于 2024-08-30 10:37:47 发布

原创最新推荐文章于 2024-08-30 10:37:47 发布 · 414 阅读

0 ·

CC 4.0 BY-SA版权

文章标签：

#zookeeper #源码

hadoop 专栏收录该内容

12 篇文章

订阅专栏

jmx包

这里写图片描述

从ComonNames文件中知道，org.apache.ZooKeeperService很重要

//CommonNames.java
public class CommonNames {
    public static final String DOMAIN="org.apache.ZooKeeperService";
    public static final String DATA_TREE_KEY="DataTree";
    public static final String STANDALONE_SERVER_KEY="StandaloneServer";
}

//ManagedUtil.java
//配置log4j

//MBeanRegistry.java
//不懂JMX,看不懂

//ZKMBeabInfo.java
//ZooKeeper要监控的bean的接口
public interface ZKMBeanInfo {
    public String getName();
    public boolean isHidden();
}

cli包

这里写图片描述

这个包是解析zk-cli的命令的,所有命令的就是继承自CliCommand类。看到这么命名的，就基本知道是命令模式了。

abstract public class CliCommand {
    protected ZooKeeper zk;    //要自己设置
    protected PrintStream out; //默认System.out
    protected PrintStream err; //默认System.err
    private String cmdStr;    //这个是子类传入的,如"create"
    private String optionStr; //这个也是子类传入的,如"[-s] [-e] [-c] [-t ttl] path [data] [acl]"

    public void addToMap(Map<String, CliCommand> cmdMap) {
        //记录下命令
        .3
        cmdMap.put(cmdStr, this);
    }

    abstract public CliCommand parse(String cmdArgs[]) throws CliParseException;

    abstract public boolean exec() throws CliException;

看一下CreateCommand的实现，结果发现比3.4.10还多了一些选项

public class CreateCommand extends CliCommand {
    private static Options options = new Options();
    private String[] args;
    private CommandLine cl;

    static {
        options.addOption(new Option("e", false, "ephemeral"));
        options.addOption(new Option("s", false, "sequential"));
        options.addOption(new Option("c", false, "container"));
        options.addOption(new Option("t", true, "ttl"));
    }

    public CreateCommand() {
        super("create", "[-s] [-e] [-c] [-t ttl] path [data] [acl]");
    }
}

    //用于解析输入的命令
    public CliCommand parse(String[] cmdArgs){ ... }

    //用于执行解析的命令
    //委派给父类的ZooKeeper来执行
    public boolean exec() throws CliException {
    //...
    String newPath = hasT ? 
    zk.create(path, data, acl, flags, new Stat(), ttl) : 
    zk.create(path, data, acl, flags);
    //...
    }

来，那就看看全部的命令吧

//e->ephemeral, s->sequential
//c->container, t->ttl
public class CreateCommand extends CliCommand {
    public CreateCommand() {
        super("create", "[-s] [-e] [-c] [-t ttl] path [data] [acl]");
    }
}

//v->version
public class DeleteCommand extends CliCommand {
    public DeleteCommand() {
        super("delete", "[-v version] path");
    }
}

public class DeleteAllCommand extends CliCommand {
    public DeleteAllCommand() {
        this("deleteall");
    }
}

//s->stats, w->watch
public class GetCommand extends CliCommand {
    private static Options options = new Options();
    public GetCommand() {
        super("get", "[-s] [-w] path");
    }
}

//s->stats, v->version
public class SetCommand extends CliCommand {
    public SetCommand() {
        super("set", "[-s] [-v version] path data");
    }
}

public class Ls2Command extends CliCommand {
    public Ls2Command() {
        super("ls2", "path [watch]");
    }
}

//ls ? ->help
//s->stat, w->watch, r->recurse
public class LsCommand extends CliCommand {
    public LsCommand() {
        super("ls", "[-s] [-w] [-R] path");
    }
}


//b->bytes quota, n->num quota
public class SetQuotaCommand extends CliCommand {
    public SetQuotaCommand() {
        super("setquota", "-n|-b val path");
   }
}

public class ListQuotaCommand extends CliCommand {
    public ListQuotaCommand() {
        super("listquota", "path");
    }
}

//b->bytes quota, n->num quota
public class DelQuotaCommand extends CliCommand {
    public DelQuotaCommand() {
        super("delquota", "[-n|-b] path");
    }
}

//s->stats
public class GetAclCommand extends CliCommand {
    public GetAclCommand() {
        super("getAcl", "[-s] path");
    }
}

//s->stats, v->version
public class SetAclCommand extends CliCommand {
    public SetAclCommand() {
        super("setAcl", "[-s] [-v version] path acl");
    }
}

public class AddAuthCommand extends CliCommand {
    public AddAuthCommand() {
        super("addauth", "scheme auth");
    }
}

public class CloseCommand extends CliCommand {
    public CloseCommand() {
        super("close", "");
    }
}

//s->stats, w->watch
//c->client connection string
public class GetConfigCommand extends CliCommand {
    private static Options options = new Options();
    public GetConfigCommand() {
        super("config", "[-c] [-w] [-s]");
    }
}

//s->stats
//v->required current config version
//file->path of config file to parse for membership
//members->comma-separated list of config strings for non-incremental reconfig
//add->comma-separated list of config strings for new servers
//remove->comma-separated list of server IDs to remove
public class ReconfigCommand extends CliCommand {
    public ReconfigCommand() {
        super("reconfig", "[-s] " +
                "[-v version] " +
                "[[-file path] | " +
                "[-members serverID=host:port1:port2;port3[,...]*]] | " +
                "[-add serverId=host:port1:port2;port3[,...]]* " +
                "[-remove serverId[,...]*]");
    }
}

//c->child watcher type
//d->data watcher type
//a->any watcher type
//l->remove locally when there is no server connection
public class RemoveWatchesCommand extends CliCommand {
    public RemoveWatchesCommand() {
        super("removewatches", "path [-c|-d|-a] [-l]");
    }
}

//w->watch
public class StatCommand extends CliCommand {
    public StatCommand() {
        super("stat", "[-w] path");
    }
}

public class SyncCommand extends CliCommand {
    public SyncCommand() {
        super("sync", "path");
    }
}

client包

//ConnectStringParser
//解析localhost:2181,localhost:2182这种
//全部加入一个List
public final class ConnectStringParser {
    private static final int DEFAULT_PORT = 2181;

    private final String chrootPath;

    private final ArrayList<InetSocketAddress> serverAddresses = new ArrayList<InetSocketAddress>();
}

//FourLetterWordMain
//四字命令的客户端吧
//只是为了便于测试，使用了SSLSocket

//HostProvider
//StaticHostProvider
//cli连接时，是可以传入多个地址的，这里的作用就是随机分配一个地址，也算负载均衡吧
//没错，还有篇论文，这里用的将服务器打乱随机选一个。https://issues.apache.org/jira/browse/ZOOKEEPER-1355

//ZKClientConfig
//配置文件

//ZooKeeperSaslClient
//SASL全称Simple Authentication and Security Layer，是一种用来扩充C/S模式验证能力的机制。在Postfix可以利用SASL来判断用户是否有权使用转发服务，或是辨认谁在使用你的服务器。

common包

这里写图片描述

AtomicFileOutputStream: 但是没有看出哪里原子了…这个类是从HDFS直接弄过来的

public class AtomicFileOutputStream extends FilterOutputStream {
    private static final String TMP_EXTENSION = ".tmp";
    private final File origFile;
    private final File tmpFile;

        public AtomicFileOutputStream(File f) throws FileNotFoundException {
        // Code unfortunately must be duplicated below since we can't assign
        // anything
        // before calling super
        super(new FileOutputStream(new File(f.getParentFile(), f.getName()
                + TMP_EXTENSION)));
        origFile = f.getAbsoluteFile();
        tmpFile = new File(f.getParentFile(), f.getName() + TMP_EXTENSION)
                .getAbsoluteFile();
    }

AtomicFileWritingIdiom：为了提供文件的原子写入，Based on the org.apache.zookeeper.server.quorum.QuorumPeer.writeLongToFile(…) idiom ，using the HDFS AtomicFileOutputStream class.

public class AtomicFileWritingIdiom {

    public static interface OutputStreamStatement {

        public void write(OutputStream os) throws IOException;

    }

    public static interface WriterStatement {

        public void write(Writer os) throws IOException;

    }

    public AtomicFileWritingIdiom(File targetFile, OutputStreamStatement osStmt)  throws IOException {
        this(targetFile, osStmt, null);
    }

    public AtomicFileWritingIdiom(File targetFile, WriterStatement wStmt)  throws IOException {
        this(targetFile, null, wStmt);
    }

    private AtomicFileWritingIdiom(File targetFile, OutputStreamStatement osStmt, WriterStatement wStmt)  throws IOException {
        AtomicFileOutputStream out = null;
        boolean error = true;
        try {
            out = new AtomicFileOutputStream(targetFile);
            if (wStmt == null) {
                // execute output stream operation
                osStmt.write(out);
            } else {
                BufferedWriter bw = new BufferedWriter(new OutputStreamWriter(out));
                // execute writer operation and flush
                wStmt.write(bw);
                bw.flush();
            }
            out.flush();
            // everything went ok
            error = false;
        } finally {
            // nothing interesting to do if out == null
            if (out != null) {
                if (error) {
                    // worst case here the tmp file/resources(fd) are not cleaned up
                    // and the caller will be notified (IOException)
                    out.abort();
                } else {
                    // if the close operation (rename) fails we'll get notified.
                    // worst case the tmp file may still exist
                    IOUtils.closeStream(out);
                }
            }
        }
    }

}

IOUtil

closeStream(Closeable stream)

cleanup(Logger log, Closeable... closeables)

copyBytes(InputStream in, OutputStream out,int buffSize, boolean close) 

copyBytes(InputStream in, OutputStream out, int buffSize)

PathTrie:有空好好研究，这东西是一个单词树

这里写图片描述

PathUtil: 验证路径没有错, 和Window里面的//进行转换

public static void validatePath(String path, boolean isSequential) 

public static void validatePath(String path)

public static String normalizeFileSystemPath(String path)

StringUtil: 分割和拼接字符串，默认是分割成String[]，这里改进为列表

public static List<String> split(String value, String separator)

public static String joinStrings(List<String> list, String delim)

ZooKeeper源码(2)cli,client,common,jmx,version包

jmx包

从ComonNames文件中知道，org.apache.ZooKeeperService很重要

cli包

这个包是解析zk-cli的命令的,所有命令的就是继承自CliCommand类。看到这么命名的，就基本知道是命令模式了。

看一下CreateCommand的实现，结果发现比3.4.10还多了一些选项

client包

common包

AtomicFileOutputStream: 但是没有看出哪里原子了…这个类是从HDFS直接弄过来的

AtomicFileWritingIdiom：为了提供文件的原子写入，Based on the org.apache.zookeeper.server.quorum.QuorumPeer.writeLongToFile(…) idiom ，using the HDFS AtomicFileOutputStream class.

IOUtil

PathTrie:有空好好研究，这东西是一个单词树

PathUtil: 验证路径没有错, 和Window里面的//进行转换

StringUtil: 分割和拼接字符串，默认是分割成String[]，这里改进为列表

Time: 时间，略过

X509Util和ZKConfig大多属性标记废弃了,X.509是一种非常通用的证书格式。所有的证书都符合ITU-T X.509国际标准，因此(理论上)为一种应用创建的证书可以用于任何其他符合X.509标准的应用。

version包

就一个VerGen类，输出当前ZooKeeper版本信息