hadoop hdfs-default.xml配置文件

name	value	description
dfs.namenode.logging.level	info	The logging level for dfs namenode. Other values are "dir"(trac e namespace mutations), "block"(trace block under/over replications and block creations/deletions), or "all".
dfs.secondary.http.address	0.0.0.0:50090	The secondary namenode http server address and port. If the port is 0 then the server will start on a free port.
dfs.datanode.address	0.0.0.0:50010	The address where the datanode server will listen to. If the port is 0 then the server will start on a free port.
dfs.datanode.http.address	0.0.0.0:50075	The datanode http server address and port. If the port is 0 then the server will start on a free port.
dfs.datanode.ipc.address	0.0.0.0:50020	The datanode ipc server address and port. If the port is 0 then the server will start on a free port.
dfs.datanode.handler.count	3	The number of server threads for the datanode.
dfs.http.address	0.0.0.0:50070	The address and the base port where the dfs namenode web ui will listen on. If the port is 0 then the server will start on a free port.
dfs.https.enable	false	Decide if HTTPS(SSL) is supported on HDFS
dfs.https.need.client.auth	false	Whether SSL client certificate authentication is required
dfs.https.server.keystore.resource	ssl-server.xml	Resource file from which ssl server keystore information will be extracted
dfs.https.client.keystore.resource	ssl-client.xml	Resource file from which ssl client keystore information will be extracted
dfs.datanode.https.address	0.0.0.0:50475
dfs.https.address	0.0.0.0:50470
dfs.datanode.dns.interface	default	The name of the Network Interface from which a data node should report its IP address.
dfs.datanode.dns.nameserver	default	The host name or IP address of the name server (DNS) which a DataNode should use to determine the host name used by the NameNode for communication and display purposes.
dfs.replication.considerLoad	true	Decide if chooseTarget considers the target's load or not
dfs.default.chunk.view.size	32768	The number of bytes to view for a file on the browser.
dfs.datanode.du.reserved	0	Reserved space in bytes per volume. Always leave this much space free for non dfs use.
dfs.name.dir	${hadoop.tmp.dir}/dfs/name	Determines where on the local filesystem the DFS name node should store the name table(fsimage). If this is a comma-delimited list of directories then the name table is replicated in all of the directories, for redundancy.
dfs.name.edits.dir	${dfs.name.dir}	Determines where on the local filesystem the DFS name node should store the transaction (edits) file. If this is a comma-delimited list of directories then the transaction file is replicated in all of the directories, for redundancy. Default value is same as dfs.name.dir
dfs.web.ugi	webuser,webgroup	The user account used by the web interface. Syntax: USERNAME,GROUP1,GROUP2, ...
dfs.permissions	true	If "true", enable permission checking in HDFS. If "false", permission checking is turned off, but all other behavior is unchanged. Switching from one parameter value to the other does not change the mode, owner or group of files or directories.
dfs.permissions.supergroup	supergroup	The name of the group of super-users.
dfs.block.access.token.enable	false	If "true", access tokens are used as capabilities for accessing datanodes. If "false", no access tokens are checked on accessing datanodes.
dfs.block.access.key.update.interval	600	Interval in minutes at which namenode updates its access keys.
dfs.block.access.token.lifetime	600	The lifetime of access tokens in minutes.
dfs.data.dir	${hadoop.tmp.dir}/dfs/data	Determines where on the local filesystem an DFS data node should store its blocks. If this is a comma-delimited list of directories, then data will be stored in all named directories, typically on different devices. Directories that do not exist are ignored.
dfs.datanode.data.dir.perm	755	Permissions for the directories on on the local filesystem where the DFS data node store its blocks. The permissions can either be octal or symbolic.
dfs.replication	3	Default block replication. The actual number of replications can be specified when the file is created. The default is used if replication is not specified in create time.
dfs.replication.max	512	Maximal block replication.
dfs.replication.min	1	Minimal block replication.
dfs.block.size	67108864	The default block size for new files.
dfs.df.interval	60000	Disk usage statistics refresh interval in msec.
dfs.client.block.write.retries	3	The number of retries for writing blocks to the data nodes, before we signal failure to the application.
dfs.blockreport.intervalMsec	3600000	Determines block reporting interval in milliseconds.
dfs.blockreport.initialDelay	0	Delay for first block report in seconds.
dfs.heartbeat.interval	3	Determines datanode heartbeat interval in seconds.
dfs.namenode.handler.count	10	The number of server threads for the namenode.
dfs.safemode.threshold.pct	0.999f	Specifies the percentage of blocks that should satisfy the minimal replication requirement defined by dfs.replication.min. Values less than or equal to 0 mean not to start in safe mode. Values greater than 1 will make safe mode permanent.
dfs.safemode.extension	30000	Determines extension of safe mode in milliseconds after the threshold level is reached.
dfs.balance.bandwidthPerSec	1048576	Specifies the maximum amount of bandwidth that each datanode can utilize for the balancing purpose in term of the number of bytes per second.
dfs.hosts		Names a file that contains a list of hosts that are permitted to connect to the namenode. The full pathname of the file must be specified. If the value is empty, all hosts are permitted.
dfs.hosts.exclude		Names a file that contains a list of hosts that are not permitted to connect to the namenode. The full pathname of the file must be specified. If the value is empty, no hosts are excluded.
dfs.max.objects	0	The maximum number of files, directories and blocks dfs supports. A value of zero indicates no limit to the number of objects that dfs supports.
dfs.namenode.decommission.interval	30	Namenode periodicity in seconds to check if decommission is complete.
dfs.namenode.decommission.nodes.per.interval	5	The number of nodes namenode checks if decommission is complete in each dfs.namenode.decommission.interval.
dfs.replication.interval	3	The periodicity in seconds with which the namenode computes repliaction work for datanodes.
dfs.access.time.precision	3600000	The access time for HDFS file is precise upto this value. The default value is 1 hour. Setting a value of 0 disables access times for HDFS.
dfs.support.append	false	Does HDFS allow appends to files? This is currently set to false because there are bugs in the "append code" and is not supported in any prodction cluster.
dfs.namenode.delegation.key.update-interval	86400000	The update interval for master key for delegation tokens in the namenode in milliseconds.
dfs.namenode.delegation.token.max-lifetime	604800000	The maximum lifetime in milliseconds for which a delegation token is valid.
dfs.namenode.delegation.token.renew-interval	86400000	The renewal interval for delegation token in milliseconds.
dfs.datanode.failed.volumes.tolerated	0	The number of volumes that are allowed to fail before a datanode stops offering service. By default any volume failure will cause a datanode to shutdown.