Syntax : hadoop fsck / COMMAND_OPTION Description path Start checking from this path. -delete Delete corrupted files. -files Print out files being checked. -files -blocks Print out the block report -files -blocks -locations Print out locations for every block. -files -blocks -racks Print out network topology for data-node locations. -includeSnapshots Include snapshot data if the given path indicates a snapshottable directory or there are snapshottable directories under it. -list-corruptfileblocks Print out list of missing blocks and files they belong to. -move Move corrupted files to /lost+found. -openforwrite Print out files opened for write. HDFS support...
Optimization Techniques Map Reduce && Hive: • Indexing • Partitioning • Bucketing • Denormalization • Vectorization =SET hive.vectorized.execution.enabled=true • Input format selection(Type of file to be used) • Unit Testing • Sampling. MAPREDUCE COUNTERS: • Counters in MR are useful for gathering statistics about MR jobs like quality control and application level. • Each counter is defined by MP framework. • Counters are useful for problem solving diagnosis. • Each counter in MR is named by ‘ENUM’. • Hadoop counters validate the following: It reads and written the correct number of bytes. Each MR job has run correct number of tasks ornot. Counters also validate amount of CPU or memory consumed is appropriate for our jobs & cluster nodes or not. Different types of counters in hadoop: Built-in or pre-defined counters User-defined counters or custom counters Built-in counters: • Apache hadoop contains some built-...
Hive Use Case – Real Estate Analysis Due to an industry, real estate activity is outlined as any economic dealings associated with the acquisition, sale, owner-operation or lease of property. This in addition includes income-generating residential properties, like flat, buildings and single-room rentals. Real estate services are not enclosed within the sector. Also, samples of real estate services embrace brokerages, property management, appraisers, investment property analysts and different consultants. All analysts, working with Big Data are using Hive or some other tool to query dataset and get results with ease. Although other querying languages exists, Hive gives us a variety of new features when compared to traditional approaches. So,On demand of accelerating consumers in real estate field, filtered series of information was collected and handed over to data analyst team. Load data into Hive. Problem Statement: ...
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