catv combiner

@ localhost root_fs] # ls-l Total 12 Drwxr-XR-x 2 root Root 4096 Oct 19 05: 41bin Lrwxrwxrwx 1 Root 11 Oct 22 11: 17 linuxrc-> bin/busybox Drwxr-XR-x 2 root Root 4096 Oct 22 18: 43 sbin Drwxr-XR-x 4 Root 4096 Oct 22 16: 52usr Go to the bin directory and you can see that all these files are links to busybox (except busybox itself ). [Root @ localhostroot_fs] # ls bin-l Total 0 Lrwxrwxrwx 1 Root 7 Oct 22 11: 17 addgroup-> busybox Lrwxrwxrwx 1 Root 7 Oct 22 11: 17 adduser-> busybox Lrwxrwxrwx 1 Ro

Use the timestamp column type, Column Type display format Timestamp (14) yyyymmddhhmmss Timestamp (12) yymmddhhmmss Timestamp (10) yymmddhhmm Timestamp (8) yyyymmdd Timestamp (6) yymmdd Timestamp (4) yymm Timestamp (2) YY It will automatically mark your insert or update operations with the current date and time. If a table has multiple timestamp columns, only the first one is automatically updated. In the following cases, MySQL automatically updates the first timestamp column as the current

generally uses DMT modulation to implement digital transmission on a pair of Copper Twisted Pair wires. the downlink speed of VDSL can reach 13 ~ 52 Mbps, uplink speed up to 1.5 ~ 7 Mbps, the transmission distance is about 300 meters ~ 1.3 km. Fttx + LAN Fttb + LAN (LAN) broadband access network in fttx is the most reasonable, practical, and cost-effective broadband access method.CommunityAnd 10 MB to the building and 10 MB to the user. It provides high-speed access for residential users. I

DefinedWhen the optical fiber is transferred to the joint, a certain amount of loss is called weld loss or continuous loss.ReasonThe optical fiber fusion loss is mainly composed of the transmission loss of the optical fiber and the weld loss of the fiber weld joint. Because the optical fiber connection quality affects the optical fiber transmission loss's passenger limit, the optical fiber line does not relay the transmission distance and so on the parameter, therefore should reduce the optical

method, that is, a convenient way to find online users; To improve efficiency and convenience to end-users, some of the addresses can be used directly as domain names, and as a result of the use of the original computer networks, The service of CATV Network and Telecommunication network is classified and coded, so it is also called "New generation security and reliable information integrated network protocol". Decimal network refers to the use of de

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interconnection with the world's large-scale construction of SDH networks. The purpose of using the SRP protocol is to identify each IP packet in the cascaded net load of SDH and provide bandwidth reuse/reuse and other control functions. It is precisely because DPT uses SDH in frame format that DPT can operate on all current fibre-optic transport infrastructures, including: * Bare Optical fiber (Dark fiber); * Wavelength Division multiplexing Equipment (DWDM); * Sdh/sonet point-to-point pat

cost. That is, to solve the problem of the up/down path in the optical fiber transmission system, it is necessary to minimize the cost of inserting/splitting wavelength. Optical fiber for transmission The application of optical fiber technology in transmission system is firstly realized by various optical networks. Up to now, the topology structure of all kinds of optical fiber transmission network can be divided into three kinds: Star shape, total shape and ring. Furthermore, from the layere

wisdom the tool, provides the omni-directional information exchange function, helps the family and the outside to keep the information exchange unimpeded, optimizes people's life Help people to effectively arrange time, enhance the safety of home life, and even save money for various energy costs. Modern society's home life, not only to be convenient and comfortable, but also intelligent, entertainment, security, which requires a good home wiring system. Home wiring is the home room of the "me

, reliability, QoS guarantee, multicast, business separation and so on to meet the new value-added business development. Gepon technology has great advantage in broadband access, has incomparable features such as ADSL and LAN, and more efficiently meets the demand of FTTH multiple service access than Apon, Bpon, GPON and MSTP. In the early stage of the market FTTH application, the Gepon system will be a good choice for the new upscale community and the existing cell bandwidth expansion. Gepon sy

of the CATV, or receive satellite signal, video camera sent live broadcast program  audio and video signal, the signal sent by the VCR and other foreign signals, sent to the MMDS launch system, after processing feed to the launch tower, and then by the antenna launch, the antenna can be a fully-shaped 360°), heart-shaped 180°, Fan 45°,80°,110°. Within certain coverage, the client's RF system receives the MMDS signal and is processed to the user t

. Create job Job Job = new Job (Conf,defaultmapreduce.class.getsimplename ()); 3, set run Jar Job.setjarbyclass (Defaultmapreduce.class); 4, set InputFormat Job.setinputformatclass (Textinputformat.class); 5, set input path Fileinputformat.addinputpath (Job, New Path (args[0)); 6, set mapper Job.setmapperclass (Mapper.class); 7, set map Output Key/value class Job.setmapoutputkeyclass (Longwritable.class); Job.setmapoutputvalueclass (Text.class); 8, set partion Job

shuffle class operator as far as possible Principle five: Shuffle operations using map-side pre-aggregation The so-called map-size pre-aggregation, which aggregates the same key at each node, is similar to the local combiner in MapReduce. Where possible, the Reducebykey or Aggregatebykey operator is used to replace the groupbykey operator. The Groupbykey operator does not perform a pre aggregation. Principle VI: Using high-performance operators Use R

, Longstream, and Doublestream are instances. The following is a two-part introduction to Convergence: Variable convergence: The accumulation of input elements into a variable container, such as collection or StringBuilder; other convergence: Removing the rest of the variable aggregation is not usually done by repeatedly modifying a mutable object, This is done repeatedly by taking the previous convergence as the next entry. such as Reduce,count,allmatch, 4.1 variable convergence A variable agg

shard will have a map task to handle, by default, the size of one block in HDFs (64M by default) is a shard, and of course we can set the size of the block. The result of the map output is temporarily placed in a ring memory buffer (the buffer size defaults to 100M, controlled by the Io.sort.mb property), when the buffer is about to overflow (default is 80% of the buffer size, Controlled by the Io.sort.spill.percent property, an overflow file is created in the local file system and the data in

) Throw new ArgumentNullException ("isEmpty "); // Result set List AabbList = new List (); // Temporary variable. Combiner box subscript discovered during a merge process List IntersectList = new List (); For (int y = area. Top; y { For (int x = area. Left; x { If (isInterest (x, y) = false) Continue; IntersectList. Clear (); Rectangle rect = new Rectangle (x, y, 1, 1 ); // Traverse and merge existing Pack

(Serializerclass) Partitioned.mappartitionswithcontext ((context, iter) = {new interruptibleiterator (context, Aggregator.combinecombinersbykey (ITER, Context))}, preservespartitioning = true)} else { //Don ' t apply map-side combiner. val values = new shuffledrdd[k, V, (K, V)] (self, partitioner). Setserializer (Serializerclass) Values.mappartitionswithcontext ((context, iter) = {true)}} Reducebykey will eventually call Combinebykey, in wh

different personalities and is competitive with each other. Then there are different teams, and products and R D are opposite to each other. Even a company has different internal factions, as small as a family, brothers will break down the wall and talk about each other in the end. They compete for rights. Except for their own people, they are not their own people. Even if they are others, they will not be able to stop at any time. Because there are different people, the product needs to be ch

Content Note Next day 1th topic: Thorough Mastery of MapReduce(from a code perspective to analyze the specific process of mapreduce execution and the ability to develop MapReduce code)1. The classic steps of MapReduce execution2, wordcount operation Process Analysis3, mapper and reducer analysis4. Custom writable5, the difference between the old and new APIs and how to use the API6. Package the MapReduce program into a jar package and run it at the command line2nd top

the knot in your heart, everything on the outside will open up. Not bound by any knowledge, with baby-like simplicity and simplicity in the nature of the observation of things, the true sense of freedom.* A combiner must be able to keep his mind simple and have only one goal in his mind-how to fight. He must remove obstacles that impede his forward, whether physical, emotional, or knowledge.* To understand the truth of martial arts and to understand