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 ...
1, metadata (Metadata): Maintenance of HDFs file System file and directory information, divided into memory metadata and metadata file two kinds. Namenode maintains the entire metadata. HDFs implementation, the method of periodically exporting metadata is not adopted, but the backup mechanism of metadata mirroring file (fsimage) + day file (edits) is adopted. 2, Block: The contents of the file. Search path Flow: &http://www.aliyun.com/zixun/aggregation/37 ...
Two days ago, at the invitation of a boss, for product planning to do a lecture. Because the preparation is not very sufficient, speak also a little short, so may be in many students listen to, there will be some boring and irrelevant. So simply retell the handout, for all interested students to criticize the advice. Preface a design to give lectures to the planners, how much also is a cross occupation, so finally selected a relatively simple and effective on both sides-"competition analysis"-to do the theme. In other words, design and planning have something in common. We are engaged in the design, in fact, can ...
The difference between excellent design and excellent design is relatively small. The average person may not be able to explain the specific differences of the outstanding design, but they can find their favorite web design works. By contrasting a few excellent works, I have summed up a few details as distinguished design. Not long ago, I wrote a 4 excellent website http://www.aliyun.com/zixun/aggregation/8912.html "> Design principles." Now this article is a bit like the continuation of the previous article. In the last article ...
★ Because most of the current content is Korean transliteration, so with the mainland official translation may be different. The last time I explained to you about the boxing and the Octupole boxing today to introduce the sword spirit is currently open to one of the four ethnic groups of the Lin-Men with the arms and China's actual existence of the Mao-Shan faction. OK today will introduce the world very very very much look forward to the Super card of the race Lin! When you see the Lin clan, you will suddenly think of the Desert Fox! (Reporter in order to shoot this guy made a special trip to the zoo-) to analyze the wonderful phosphate ...
&http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp; The color ring is a tool to help us understand the relationship between color and color. The most common color rings are 12 color rings. Usually a color ring contains at least 6, up to 24, 48, 96, or more colors. Yellow-green, blue-green, blue-purple, purple-red, red, orange, orange, yellow-orange, three-colour rings with three primary colors. They are red, yellow, blue ...
Intermediary transaction http://www.aliyun.com/zixun/aggregation/6858.html ">seo diagnose Taobao guest Cloud host Technology Hall website optimization method is a relatively abstract technology, at the beginning without basic words very difficult to understand correctly; But there is no relationship, as long as the bottom of the Gen can understand the general principle, and the optimization of the details and tips is the need for time and practice gradually accumulated experience. Technical level is very difficult to use a standard to measure, we learn ...
NoSQL Recent momentum is good, http://www.aliyun.com/zixun/aggregation/13461.html ">mongodb is one of the Jiao jiao, oneself learn nosql when also reference a lot of information, The final decision to start from the MongoDB, the most important reason has two: 1 oneself is a simple amateur, all problems I think whether there is a simple way to solve, rather stop to think a lot of time, also do not want to use stupid method to do immediately, and Mong ...
Func_get_args (PHP4 >= 4.0b4) Func_get_args---&http://www.aliyun.com/zixun/aggregation/37954.html ">nbsp; Returns the array syntax for the argument list containing the function: int Func_get_args (void) Description: Returns an array of elements that are equivalent to the current user-defined letter ...
Swf_getfontinfo (PHP4 >= 4.0rc2) swf_getfontinfo---&http://www.aliyun.com/zixun/aggregation/37954.html "> nbsp; Gets the height of the uppercase A and lowercase x for how many pixel syntax: array swf_getfontinfo (void); Description: Swf_getfont ...
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