String Exception

To use Hadoop, data consolidation is critical and hbase is widely used. In general, you need to transfer data from existing types of databases or data files to HBase for different scenario patterns. The common approach is to use the Put method in the HBase API, to use the HBase Bulk Load tool, and to use a custom mapreduce job. The book "HBase Administration Cookbook" has a detailed description of these three ways, by Imp ...

1. HQueue profile HQueue is a set of distributed, persistent message queues developed by hbase based on the search web crawl offline Systems team. It uses htable to store message data, HBase coprocessor to store the original keyvalue data in the message data format, and encapsulates the HBase client API for message access based on the HQueue client API. HQueue can be effectively used in the need to store time series data, as MAPR ...

1. Prepare to work, after installing good habse, execute hbase Shell create ' table name ', ' column name 1 ', ' Column Name 2 ', ' Column name n ' create ' table name ', ' column family name ' in HBase column can be dynamically added, only need to have a row family on it Create ' Test_lcc_person ', ' Lcc_liezu ' and then add some data key the same is a piece of data, a total of 6 data put ' table name ', ' Rowk ...

This article is my second time reading Hadoop 0.20.2 notes, encountered many problems in the reading process, and ultimately through a variety of ways to solve most of the. 　　Hadoop the whole system is well designed, the source code is worth learning distributed students read, will be all notes one by one post, hope to facilitate reading Hadoop source code, less detours. 1 serialization core Technology The objectwritable in 0.20.2 version Hadoop supports the following types of data format serialization: Data type examples say ...

This article is the fifth article in the introductory teaching of Windows Azure AppFabric. This article provides a preliminary explanation of access control Service (ACS) in AppFabric. For subsequent learning to proceed smoothly make sure that you have browsed through the first article of this tutorial, and that you have completed the creation of the AppFabric project and namespace in this article. We know that Appfabirc by service bus and Access control ...

Note: The latest hbase shell has canceled hql support, which means that the INSERT and query SQL statements in the following data are not available. For efficiency reasons, there are now only a few ways to work with data, such as Get,put,scan. Url:http://hadoop.apache.org/hbase/docs/r0.1.1/api/overview-summary.html built on the HDFS based on the building 1: Modify Hadoop/contrib ...

The disadvantage of using HDFS to save a large number of small files with use using the: 1.Hadoop Namenode saves "meta information" data for all files in memory. According to statistics, each file needs to consume NameNode600 bytes of memory. If you need to save a large number of small files will cause great pressure on the namenode. 2. If the use of Hadoop MapReduce small file processing, then the number of Mapper will be the number of small files into a linear correlation (Note: Filei ...

Flume-based Log collection system (i) architecture and Design Issues Guide: 1. Flume-ng and scribe contrast, flume-ng advantage in where? 2. What questions should be considered in architecture design? 3.Agent crash how to solve? Does 4.Collector crash affect? What are the 5.flume-ng reliability (reliability) measures? The log collection system in the United States is responsible for the collection of all business logs from the United States Regiment and to the Hadoop platform respectively ...

This paper is an excerpt from the book "The Authoritative Guide to Hadoop", published by Tsinghua University Press, which is the author of Tom White, the School of Data Science and engineering, East China Normal University. This book begins with the origins of Hadoop, and integrates theory and practice to introduce Hadoop as an ideal tool for high-performance processing of massive datasets. The book consists of 16 chapters, 3 appendices, covering topics including: Haddoop;mapreduce;hadoop Distributed file system; Hadoop I/O, MapReduce application Open ...

I believe many people have been puzzled by C # delegates and events, especially in C # beginners, it will feel more difficult to learn this part, very likely to give up, and. 　　NET for delegates and events encapsulation is very good, generally not how to use custom delegates and events, so give up learning the technology has an excuse! There are a number of such articles on the web, most representative of Zhang Ziyang's C # delegates and events this article, the writing is very good, received a lot of readers praise, but I read the comments, or found some problems, because there are many readers are read over and over, each feeling is quite ...