mapreduce simplified data processing on large clusters

tolerent and is designed to be deployed on low-cost (low-cost) hardware. It also provides high throughput to access application data, suitable for applications with large data sets. HDFS relaxed (relax) POSIX requirements (requirements) so that you can access the data in the streaming Access File System in the form of

folder within the/user/root/folder in HDFs, put Delimiters.txt, stopwords.txt into the Data folder, and create a new titles folder in the Data folder, Cloudmr/interna The four text files in the L_use/tmp/dataset/titles directory are placed in the titles folder.Describes the relevant commands:Hadoop fs-ls Lists the HDFs directory, because there are no parameters, the current user's home directory is listedH

1, through the traditional Key-value class analysis dataWhen you create a key class, all keys inherit the Writablecomparable interfacepublic class Sendorkey implements Writablecomparable{Default Constructor+parameterized constructorImplementation of ReadFields methodImplementation of Write methodOverriding the Compare to method}Sensorkey.javaSensorvalue.java"Note: The default constructor initializes the variableConstructors with parameters initialize class variables with their parameter valuesTh

sort by the frequency of the query. 2). 10 million strings, some of which are the same (repeat), need to remove all duplicates, and keep no duplicate strings. How to design and implement? 3). Search for popular queries: The query string has a high degree of repetition, although the total is 10 million, but if the repetition is removed, no more than 3 million, each less than 255 bytes. 10. Distributed Processing

frequency of query. 2.10 million strings, some of which are the same (repeat), need to remove all duplicates, leaving no duplicate strings. How do I design and implement? 3. Find Hot query: query string is a high degree of repetition, although the total is 10 million, but if the removal of duplicates, no more than 3 million, each no more than 255 bytes. 10. Distributed Processing MapReduce Scope of app

file stores the user's query, and the query of each file may be repeated. Sort the query frequency. 2). 10 million character strings, some of which are the same (repeated). You need to remove all repeated strings and keep the strings that are not repeated. How can I design and implement it? 3). Search for hot queries: the query string has a high repeat level. Although the total number is 10 million, if the number of duplicate queries is not more than 3 million, each query must not exceed 255 by

: compression implementation. Problem example:1) there are 10 files, each of which is 1 GB. each row of each file stores the user's query, and the query of each file may be repeated. Sort the query frequency. 2). 10 million strings, some of which are the same (repeated). You need to remove all the duplicates and keep the strings that are not repeated. How can I design and implement it? 3). Search for hot queries: the query string has a high degree of repetition. Although the total number is 10 m

no duplicate strings. How do I design and implement? 3. Find Hot query: query string is a high degree of repetition, although the total is 10 million, but if the removal of duplicates, no more than 3 million, each no more than 255 bytes. 10. Distributed Processing MapReduceScope of application: Large amount of data, but small

are 10 files, each of which is 1 GB. each row of each file stores the user's query, and the query of each file may be repeated. Sort the query frequency.2). 10 million strings, some of which are the same (repeated). You need to remove all the duplicates and keep the strings that are not repeated. How can I design and implement it?3). Search for hot queries: the query string has a high degree of repetition. Although the total number is 10 million, if the number of duplicate queries is not more t

may be repeated. Sort the query frequency.2). 10 million character strings, some of which are the same (repeated). You need to remove all repeated strings and keep the strings that are not repeated. How can I design and implement it?3). Search for hot queries: the query string has a high repeat level. Although the total number is 10 million, if the number of duplicate queries is not more than 3 million, each query must not exceed 255 bytes.10. Distributed P