Hi Pranshu, You can follow the instructions in the link below: https://community.hortonworks.com/articles/4427/fix-under-replicated-blocks-in-hdfs-manually.html Regards, Karthik Gopal ... View more

Hi Rushikesh, Hadoop jobs are data intensive, compressing data can speed up the I/O operations - MapReduce jobs are almost always I/O bound Compressed data can save storage space and speed up data transfers across the network - Capital allocation for hardware can go further Reduced I/O and network load can bring significant performance improvements - MapReduce jobs can finish faster overall On the other hand, CPU utilization and processing time increases during compression and decompression - Understanding the tradeoff is important for MapReduce pipeline's overall performance ... View more

Hi Rushikesh, You can create a daily script and use the following option of hadoop fs command to append the an existing file on HDFS. Usage: hadoop fs -appendToFile <localsrc> ... <dst> Append single src, or multiple srcs from local file system to the destination file system. Also reads input from stdin and appends to destination file system. hadoop fs -appendToFile localfile /user/hadoop/hadoopfile hadoop fs -appendToFile localfile1 localfile2 /user/hadoop/hadoopfile hadoop fs -appendToFile localfile hdfs://nn.example.com/hadoop/hadoopfile hadoop fs -appendToFile - hdfs://nn.example.com/hadoop/hadoopfile Reads the input from stdin. Exit Code: Returns 0 on success and 1 on error. ... View more