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The following page has been changed by KonstantinShvachko: http://wiki.apache.org/hadoop/FAQ ------------------------------------------------------------------------------ The only purpose of the secondary name-node is to perform periodic checkpoints. The secondary name-node periodically downloads current name-node image and edits log files, joins them into new image and uploads the new image back to the (primary and the only) name-node. + See [http://hadoop.apache.org/core/docs/current/hdfs_user_guide.html#Secondary+Namenode JavaDoc] So if the name-node fails and you can restart it on the same physical node then there is no need to shutdown data-nodes, just the name-node need to be restarted. @@ -303, +304 @@ GridGain does not support data intensive jobs. For more details, see HadoopVsGridGain. + [[BR]] + [[Anchor(21)]] + '''21. [#21 HDFS. Can I have multiple files in HDFS use different block sizes?]''' + + Yes. HDFS provides api to specify block size when you create a file. [[BR]] + See + [http://hadoop.apache.org/core/docs/current/api/org/apache/hadoop/fs/FileSystem.html#create(org.apache.hadoop.fs.Path,%20boolean,%20int,%20short,%20long) FileSystem.create(Path, overwrite, bufferSize, replication, blockSize, progress)] +
