hadoop.common.configuration.version 0.23.0 version of this configuration file hadoop.tmp.dir /tmp/hadoop-${user.name} A base for other temporary directories. io.native.lib.available true Should native hadoop libraries, if present, be used. hadoop.http.filter.initializers org.apache.hadoop.http.lib.StaticUserWebFilter A comma separated list of class names. Each class in the list must extend org.apache.hadoop.http.FilterInitializer. The corresponding Filter will be initialized. Then, the Filter will be applied to all user facing jsp and servlet web pages. The ordering of the list defines the ordering of the filters. hadoop.security.authorization false Is service-level authorization enabled? hadoop.security.authentication simple Possible values are simple (no authentication), and kerberos hadoop.security.group.mapping org.apache.hadoop.security.ShellBasedUnixGroupsMapping Class for user to group mapping (get groups for a given user) for ACL hadoop.security.groups.cache.secs 300 This is the config controlling the validity of the entries in the cache containing the user->group mapping. When this duration has expired, then the implementation of the group mapping provider is invoked to get the groups of the user and then cached back. hadoop.security.service.user.name.key For those cases where the same RPC protocol is implemented by multiple servers, this configuration is required for specifying the principal name to use for the service when the client wishes to make an RPC call. hadoop.rpc.protection authentication This field sets the quality of protection for secured sasl connections. Possible values are authentication, integrity and privacy. authentication means authentication only and no integrity or privacy; integrity implies authentication and integrity are enabled; and privacy implies all of authentication, integrity and privacy are enabled. hadoop.work.around.non.threadsafe.getpwuid false Some operating systems or authentication modules are known to have broken implementations of getpwuid_r and getpwgid_r, such that these calls are not thread-safe. Symptoms of this problem include JVM crashes with a stack trace inside these functions. If your system exhibits this issue, enable this configuration parameter to include a lock around the calls as a workaround. An incomplete list of some systems known to have this issue is available at http://wiki.apache.org/hadoop/KnownBrokenPwuidImplementations hadoop.kerberos.kinit.command kinit Used to periodically renew Kerberos credentials when provided to Hadoop. The default setting assumes that kinit is in the PATH of users running the Hadoop client. Change this to the absolute path to kinit if this is not the case. hadoop.logfile.size 10000000 The max size of each log file hadoop.logfile.count 10 The max number of log files io.file.buffer.size 4096 The size of buffer for use in sequence files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. io.bytes.per.checksum 512 The number of bytes per checksum. Must not be larger than io.file.buffer.size. io.skip.checksum.errors false If true, when a checksum error is encountered while reading a sequence file, entries are skipped, instead of throwing an exception. io.compression.codecs org.apache.hadoop.io.compress.DefaultCodec,org.apache.hadoop.io.compress.GzipCodec,org.apache.hadoop.io.compress.BZip2Codec,org.apache.hadoop.io.compress.DeflateCodec,org.apache.hadoop.io.compress.SnappyCodec A list of the compression codec classes that can be used for compression/decompression. io.serializations org.apache.hadoop.io.serializer.WritableSerialization,org.apache.hadoop.io.serializer.avro.AvroSpecificSerialization,org.apache.hadoop.io.serializer.avro.AvroReflectSerialization A list of serialization classes that can be used for obtaining serializers and deserializers. io.seqfile.local.dir ${hadoop.tmp.dir}/io/local The local directory where sequence file stores intermediate data files during merge. May be a comma-separated list of directories on different devices in order to spread disk i/o. Directories that do not exist are ignored. io.map.index.skip 0 Number of index entries to skip between each entry. Zero by default. Setting this to values larger than zero can facilitate opening large MapFiles using less memory. io.map.index.interval 128 MapFile consist of two files - data file (tuples) and index file (keys). For every io.map.index.interval records written in the data file, an entry (record-key, data-file-position) is written in the index file. This is to allow for doing binary search later within the index file to look up records by their keys and get their closest positions in the data file. fs.defaultFS file:/// The name of the default file system. A URI whose scheme and authority determine the FileSystem implementation. The uri's scheme determines the config property (fs.SCHEME.impl) naming the FileSystem implementation class. The uri's authority is used to determine the host, port, etc. for a filesystem. fs.trash.interval 0 Number of minutes after which the checkpoint gets deleted. If zero, the trash feature is disabled. fs.trash.checkpoint.interval 0 Number of minutes between trash checkpoints. Should be smaller or equal to fs.trash.interval. Every time the checkpointer runs it creates a new checkpoint out of current and removes checkpoints created more than fs.trash.interval minutes ago. fs.file.impl org.apache.hadoop.fs.LocalFileSystem The FileSystem for file: uris. fs.hdfs.impl org.apache.hadoop.hdfs.DistributedFileSystem The FileSystem for hdfs: uris. fs.viewfs.impl org.apache.hadoop.fs.viewfs.ViewFileSystem The FileSystem for view file system for viewfs: uris (ie client side mount table:). fs.AbstractFileSystem.file.impl org.apache.hadoop.fs.local.LocalFs The AbstractFileSystem for file: uris. fs.AbstractFileSystem.hdfs.impl org.apache.hadoop.fs.Hdfs The FileSystem for hdfs: uris. fs.AbstractFileSystem.viewfs.impl org.apache.hadoop.fs.viewfs.ViewFs The AbstractFileSystem for view file system for viewfs: uris (ie client side mount table:). fs.s3.impl org.apache.hadoop.fs.s3.S3FileSystem The FileSystem for s3: uris. fs.s3n.impl org.apache.hadoop.fs.s3native.NativeS3FileSystem The FileSystem for s3n: (Native S3) uris. fs.kfs.impl org.apache.hadoop.fs.kfs.KosmosFileSystem The FileSystem for kfs: uris. fs.hftp.impl org.apache.hadoop.hdfs.HftpFileSystem fs.hsftp.impl org.apache.hadoop.hdfs.HsftpFileSystem fs.ftp.impl org.apache.hadoop.fs.ftp.FTPFileSystem The FileSystem for ftp: uris. fs.ftp.host 0.0.0.0 FTP filesystem connects to this server fs.ftp.host.port 21 FTP filesystem connects to fs.ftp.host on this port fs.har.impl org.apache.hadoop.fs.HarFileSystem The filesystem for Hadoop archives. fs.har.impl.disable.cache true Don't cache 'har' filesystem instances. fs.df.interval 60000 Disk usage statistics refresh interval in msec. fs.s3.block.size 67108864 Block size to use when writing files to S3. fs.s3.buffer.dir ${hadoop.tmp.dir}/s3 Determines where on the local filesystem the S3 filesystem should store files before sending them to S3 (or after retrieving them from S3). fs.s3.maxRetries 4 The maximum number of retries for reading or writing files to S3, before we signal failure to the application. fs.s3.sleepTimeSeconds 10 The number of seconds to sleep between each S3 retry. fs.automatic.close true By default, FileSystem instances are automatically closed at program exit using a JVM shutdown hook. Setting this property to false disables this behavior. This is an advanced option that should only be used by server applications requiring a more carefully orchestrated shutdown sequence. fs.s3n.block.size 67108864 Block size to use when reading files using the native S3 filesystem (s3n: URIs). io.seqfile.compress.blocksize 1000000 The minimum block size for compression in block compressed SequenceFiles. io.seqfile.lazydecompress true Should values of block-compressed SequenceFiles be decompressed only when necessary. io.seqfile.sorter.recordlimit 1000000 The limit on number of records to be kept in memory in a spill in SequenceFiles.Sorter io.mapfile.bloom.size 1048576 The size of BloomFilter-s used in BloomMapFile. Each time this many keys is appended the next BloomFilter will be created (inside a DynamicBloomFilter). Larger values minimize the number of filters, which slightly increases the performance, but may waste too much space if the total number of keys is usually much smaller than this number. io.mapfile.bloom.error.rate 0.005 The rate of false positives in BloomFilter-s used in BloomMapFile. As this value decreases, the size of BloomFilter-s increases exponentially. This value is the probability of encountering false positives (default is 0.5%). hadoop.util.hash.type murmur The default implementation of Hash. Currently this can take one of the two values: 'murmur' to select MurmurHash and 'jenkins' to select JenkinsHash. ipc.client.idlethreshold 4000 Defines the threshold number of connections after which connections will be inspected for idleness. ipc.client.kill.max 10 Defines the maximum number of clients to disconnect in one go. ipc.client.connection.maxidletime 10000 The maximum time in msec after which a client will bring down the connection to the server. ipc.client.connect.max.retries 10 Indicates the number of retries a client will make to establish a server connection. ipc.server.listen.queue.size 128 Indicates the length of the listen queue for servers accepting client connections. ipc.server.tcpnodelay false Turn on/off Nagle's algorithm for the TCP socket connection on the server. Setting to true disables the algorithm and may decrease latency with a cost of more/smaller packets. ipc.client.tcpnodelay false Turn on/off Nagle's algorithm for the TCP socket connection on the client. Setting to true disables the algorithm and may decrease latency with a cost of more/smaller packets. hadoop.rpc.socket.factory.class.default org.apache.hadoop.net.StandardSocketFactory Default SocketFactory to use. This parameter is expected to be formatted as "package.FactoryClassName". hadoop.rpc.socket.factory.class.ClientProtocol SocketFactory to use to connect to a DFS. If null or empty, use hadoop.rpc.socket.class.default. This socket factory is also used by DFSClient to create sockets to DataNodes. hadoop.socks.server Address (host:port) of the SOCKS server to be used by the SocksSocketFactory. net.topology.node.switch.mapping.impl org.apache.hadoop.net.ScriptBasedMapping The default implementation of the DNSToSwitchMapping. It invokes a script specified in topology.script.file.name to resolve node names. If the value for topology.script.file.name is not set, the default value of DEFAULT_RACK is returned for all node names. net.topology.script.file.name The script name that should be invoked to resolve DNS names to NetworkTopology names. Example: the script would take host.foo.bar as an argument, and return /rack1 as the output. net.topology.script.number.args 100 The max number of args that the script configured with topology.script.file.name should be run with. Each arg is an IP address. file.stream-buffer-size 4096 The size of buffer to stream files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. file.bytes-per-checksum 512 The number of bytes per checksum. Must not be larger than file.stream-buffer-size file.client-write-packet-size 65536 Packet size for clients to write file.blocksize 67108864 Block size file.replication 1 Replication factor s3.stream-buffer-size 4096 The size of buffer to stream files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. s3.bytes-per-checksum 512 The number of bytes per checksum. Must not be larger than s3.stream-buffer-size s3.client-write-packet-size 65536 Packet size for clients to write s3.blocksize 67108864 Block size s3.replication 3 Replication factor s3native.stream-buffer-size 4096 The size of buffer to stream files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. s3native.bytes-per-checksum 512 The number of bytes per checksum. Must not be larger than s3native.stream-buffer-size s3native.client-write-packet-size 65536 Packet size for clients to write s3native.blocksize 67108864 Block size s3native.replication 3 Replication factor kfs.stream-buffer-size 4096 The size of buffer to stream files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. kfs.bytes-per-checksum 512 The number of bytes per checksum. Must not be larger than kfs.stream-buffer-size kfs.client-write-packet-size 65536 Packet size for clients to write kfs.blocksize 67108864 Block size kfs.replication 3 Replication factor ftp.stream-buffer-size 4096 The size of buffer to stream files. The size of this buffer should probably be a multiple of hardware page size (4096 on Intel x86), and it determines how much data is buffered during read and write operations. ftp.bytes-per-checksum 512 The number of bytes per checksum. Must not be larger than ftp.stream-buffer-size ftp.client-write-packet-size 65536 Packet size for clients to write ftp.blocksize 67108864 Block size ftp.replication 3 Replication factor tfile.io.chunk.size 1048576 Value chunk size in bytes. Default to 1MB. Values of the length less than the chunk size is guaranteed to have known value length in read time (See also TFile.Reader.Scanner.Entry.isValueLengthKnown()). tfile.fs.output.buffer.size 262144 Buffer size used for FSDataOutputStream in bytes. tfile.fs.input.buffer.size 262144 Buffer size used for FSDataInputStream in bytes.