Hadoop之CommonConfigurationKeys解释,还望共同指正问号处

package org.apache.hadoop.fs;

import org.apache.hadoop.classification.InterfaceAudience;
import org.apache.hadoop.classification.InterfaceStability;

/**
 * 公用配置键常量类
 * 
 * @author root
 *
 */
@InterfaceAudience.Private
@InterfaceStability.Unstable
public class CommonConfigurationKeys extends CommonConfigurationKeysPublic {

	public static final String FS_HOME_DIR_KEY = "fs.homeDir";// 家路径键(UserHome)
	public static final String FS_HOME_DIR_DEFAULT = "/user";// 家路径值
	
	public static final String FS_PERMISSIONS_UMASK_KEY = "fs.permissions.umask-mode";// umask文件创建权限模式键
	public static final int FS_PERMISSIONS_UMASK_DEFAULT = 0022;// umask文件创建权限模式值
	
	public static final String IPC_PING_INTERVAL_KEY = "ipc.ping.interval";// IPC(进程通信)客户端Ping服务端的频率键
	public static final int IPC_PING_INTERVAL_DEFAULT = 60000; // IPC(进程通信)客户端Ping服务端的频率值(1分钟)
	
	public static final String IPC_CLIENT_PING_KEY = "ipc.client.ping";// 是否开启远程过程调用协议客户端的Ping功能键
	public static final boolean IPC_CLIENT_PING_DEFAULT = true;// 是否开启远程过程调用协议客户端的Ping功能值
	
	public static final String IPC_SERVER_RPC_MAX_RESPONSE_SIZE_KEY = "ipc.server.max.response.size";// 响应最大数据键(超过这个数据将被记录日志)
	public static final int IPC_SERVER_RPC_MAX_RESPONSE_SIZE_DEFAULT = 1024 * 1024;// 响应最大数据值(超过这个数据将被记录日志)
	
	public static final String IPC_SERVER_RPC_READ_THREADS_KEY = "ipc.server.read.threadpool.size";// IPC(进程通信)读取线程个数键
	public static final int IPC_SERVER_RPC_READ_THREADS_DEFAULT = 1;// IPC(进程通信)读取线程个数值

	public static final String IPC_MAXIMUM_DATA_LENGTH = "ipc.maximum.data.length";// IPC最大数据长度键
	public static final int IPC_MAXIMUM_DATA_LENGTH_DEFAULT = 64 * 1024 * 1024;// IPC最大数据长度值

	public static final String IPC_SERVER_HANDLER_QUEUE_SIZE_KEY = "ipc.server.handler.queue.size";// IPC服务允许的最大队列长度键
	public static final int IPC_SERVER_HANDLER_QUEUE_SIZE_DEFAULT = 100;// IPC服务允许的最大队列长度值

	public static final String IO_COMPRESSION_CODEC_LZO_BUFFERSIZE_KEY = "io.compression.codec.lzo.buffersize";// IO压缩的缓存大小键
	public static final int IO_COMPRESSION_CODEC_LZO_BUFFERSIZE_DEFAULT = 64 * 1024;// IO压缩的缓存大小值
	
	public static final String NET_TOPOLOGY_CONFIGURED_NODE_MAPPING_KEY = "net.topology.configured.node.mapping";// 配置的拓扑结构节点们键

	public static final String IO_COMPRESSION_CODEC_SNAPPY_BUFFERSIZE_KEY = "io.compression.codec.snappy.buffersize";// IO压缩的缓存大小键(SNAPPY)
	public static final int IO_COMPRESSION_CODEC_SNAPPY_BUFFERSIZE_DEFAULT = 256 * 1024;// IO压缩的缓存大小值(SNAPPY)

	public static final String IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_KEY = "io.compression.codec.lz4.buffersize";// IO压缩的缓存大小键(LZ4)
	public static final int IO_COMPRESSION_CODEC_LZ4_BUFFERSIZE_DEFAULT = 256 * 1024;// IO压缩的缓存大小值(LZ4)

	/**安全认证************************************************************************************************/
	
	public static final String HADOOP_SECURITY_SERVICE_AUTHORIZATION_REFRESH_POLICY = "security.refresh.policy.protocol.acl";// 刷新Acl协议文件策略(RefreshAuthorizationPolicyProtocol)
	public static final String HADOOP_SECURITY_SERVICE_AUTHORIZATION_GET_USER_MAPPINGS = "security.get.user.mappings.protocol.acl";// 获取用户配置的Acl协议文件
	public static final String HADOOP_SECURITY_SERVICE_AUTHORIZATION_REFRESH_USER_MAPPINGS = "security.refresh.user.mappings.protocol.acl";// 刷新用户配置的Acl协议文件
	public static final String SECURITY_HA_SERVICE_PROTOCOL_ACL = "security.ha.service.protocol.acl";// Acl协议文件策略(HAService)
	public static final String SECURITY_ZKFC_PROTOCOL_ACL = "security.zkfc.protocol.acl";// ?
	public static final String SECURITY_CLIENT_PROTOCOL_ACL = "security.client.protocol.acl";// Acl协议文件策略(ClientProtocol)
	public static final String SECURITY_CLIENT_DATANODE_PROTOCOL_ACL = "security.client.datanode.protocol.acl";// Acl协议文件策略(ClientDatanodeProtocol)
	public static final String SECURITY_DATANODE_PROTOCOL_ACL = "security.datanode.protocol.acl";// Acl协议文件策略(DatanodeProtocol)
	public static final String SECURITY_INTER_DATANODE_PROTOCOL_ACL = "security.inter.datanode.protocol.acl";// Acl协议文件策略(InterDatanodeProtocol)
	public static final String SECURITY_NAMENODE_PROTOCOL_ACL = "security.namenode.protocol.acl";// Acl协议文件策略(NamenodeProtocol)
	public static final String SECURITY_QJOURNAL_SERVICE_PROTOCOL_ACL = "security.qjournal.service.protocol.acl";// ?
	
	public static final String HADOOP_SECURITY_TOKEN_SERVICE_USE_IP = "hadoop.security.token.service.use_ip";// 是否令牌服务使用IP键
	public static final boolean HADOOP_SECURITY_TOKEN_SERVICE_USE_IP_DEFAULT = true;// 是否令牌服务使用IP值

	/**健康监控和控制器切换**************************************************************************************/
	
	/** How often to retry connecting to the service. */
	public static final String HA_HM_CONNECT_RETRY_INTERVAL_KEY = "ha.health-monitor.connect-retry-interval.ms";// 重试链接服务间隔时间键
	public static final long HA_HM_CONNECT_RETRY_INTERVAL_DEFAULT = 1000;// 重试链接服务间隔时间值(1秒)

	public static final String HA_HM_CHECK_INTERVAL_KEY = "ha.health-monitor.check-interval.ms";// 检查服务健康状况间隔键
	public static final long HA_HM_CHECK_INTERVAL_DEFAULT = 1000;// 检查服务健康状况间隔值(1秒)

	public static final String HA_HM_SLEEP_AFTER_DISCONNECT_KEY = "ha.health-monitor.sleep-after-disconnect.ms";// 发生RPC错误睡眠多长时间键
	public static final long HA_HM_SLEEP_AFTER_DISCONNECT_DEFAULT = 1000;// 发生RPC错误睡眠多长时间值(1秒)

	public static final String HA_HM_RPC_TIMEOUT_KEY = "ha.health-monitor.rpc-timeout.ms";// 实际检查健康状况的超时时间键
	public static final int HA_HM_RPC_TIMEOUT_DEFAULT = 45000;// 实际检查健康状况的超时时间值(45秒)

	public static final String HA_FC_NEW_ACTIVE_TIMEOUT_KEY = "ha.failover-controller.new-active.rpc-timeout.ms";// 控制器切换的等待时间之新活动键
	public static final int HA_FC_NEW_ACTIVE_TIMEOUT_DEFAULT = 60000;// 控制器切换的等待时间之新活动值

	public static final String HA_FC_GRACEFUL_FENCE_TIMEOUT_KEY = "ha.failover-controller.graceful-fence.rpc-timeout.ms";// 控制器切换的等待时间之就活动待命键
	public static final int HA_FC_GRACEFUL_FENCE_TIMEOUT_DEFAULT = 5000;// 控制器切换的等待时间之就活动待命值

	public static final String HA_FC_GRACEFUL_FENCE_CONNECTION_RETRIES = "ha.failover-controller.graceful-fence.connection.retries";// 控制器切换连接重试次数键
	public static final int HA_FC_GRACEFUL_FENCE_CONNECTION_RETRIES_DEFAULT = 1;// 控制器切换连接重试次数值

	public static final String HA_FC_CLI_CHECK_TIMEOUT_KEY = "ha.failover-controller.cli-check.rpc-timeout.ms";// 控制器切换的等待时间之CLI检查键
	public static final int HA_FC_CLI_CHECK_TIMEOUT_DEFAULT = 20000;// 控制器切换的等待时间之CLI检查值

	public static final String HADOOP_HTTP_STATIC_USER = "hadoop.http.staticuser.user";// 静态用户键See {@link StaticUserWebFilter}
	public static final String DEFAULT_HADOOP_HTTP_STATIC_USER = "dr.who";// 静态用户值

	public static final String HADOOP_JETTY_LOGS_SERVE_ALIASES = "hadoop.jetty.logs.serve.aliases";// 是否开启Jetty服务容器的日志别名键
	public static final boolean DEFAULT_HADOOP_JETTY_LOGS_SERVE_ALIASES = true;// 是否开启Jetty服务容器的日志别名值

	/**其他************************************************************************************************/
	
	public static final String KERBEROS_TICKET_CACHE_PATH = "hadoop.security.kerberos.ticket.cache.path";// Kerberos的票据缓存路径

	public static final String HADOOP_SECURITY_UID_NAME_CACHE_TIMEOUT_KEY = "hadoop.security.uid.cache.secs";// UID缓存时间键
	public static final long HADOOP_SECURITY_UID_NAME_CACHE_TIMEOUT_DEFAULT = 4 * 60 * 60;// UID缓存时间值(4小时)
	
	public static final String IPC_CLIENT_FALLBACK_TO_SIMPLE_AUTH_ALLOWED_KEY = "ipc.client.fallback-to-simple-auth-allowed";// 是否允许安全链接撤回简单连接(不需认证)键
	public static final boolean IPC_CLIENT_FALLBACK_TO_SIMPLE_AUTH_ALLOWED_DEFAULT = false;// 是否允许安全链接撤回简单连接(不需认证)值
}