catv combiner

function after the rotation of the functions, iterate and terminatepartial similar to Hadoop combiner ( Iterate--mapper;terminatepartial--reducer) Merge (): Receive terminatepartial return result, data merge operation with a return type of Boolean terminate () : Returns the result of the final aggregation function Java code "Font-size:x-small;"> Packagecom.alibaba.hive; Import Org.apache.hadoop.hive.ql.exec.UDAF; Import Org.apa

division ), you can also obtain the implementation of the recordreader interface from inputformat and generate pairs from the input. With , you can start the map operation. The map operation passes context. Collect (Outputcollector.Collect) write the result to context. When mapper outputs are collected, they are output to the output file in a specified way by the partitioner class. We can provide combiner for Map

Use to Combiner programming (pluggable)At the map end of the output to merge first, the most basic is to implement local key merge, with local reduce functionIf you do not have combiner, all results are reduce, efficiency will be underThe input and output types of the combiner should be exactly the same (implement functions such as cumulative, maximum, etc.)Job.s

set the key comparison classJob.setsortcomparatorclass (Keycomparator.class);Note: If you do not use the custom Sortcomparator class, the key is used by default in the CompareTo () method to sort keys.4. Define the Grouping class functionIn the reduce phase, a value iterator corresponding to the Key is constructed, as long as first is the same group and placed in a value iterator. There are two ways to define this comparer.1) Inherit Writablecomparatorpublic static class Groupingcomparator exte

, "title":"Fracture", "boxart":"http://cdn-0.nflximg.com/images/2891/Fracture.jpg", "URI":"http://api.netflix.com/catalog/titles/movies/70111470", "rating":5.0,}], bookmarks=[{ID:470, Time:23432}, {ID:453, Time:234324}, {ID:445, Time:987834}], counter, Videoidandbookmarkidpairs= []; for(counter =0; Counter ) { Videoidandbookmarkidpairs.push ({videoid:videos[counter].id, bookmarkid:bookmarks[c Ounter].id}) }returnVideoidandbookmarkidpai

file first; 1 final long size = (bufend >= bufstart3 ? bufend - bufstart5 : (bufvoid - bufend) + bufstart) +7 partitions * APPROX_HEADER_LENGTH; Step 2: Obtain the name of the file written to the local (non-HDFS) file with a serial number, for example, output/spill2.out. The code corresponding to the naming format is: 1 return lDirAlloc.getLocalPathForWrite(MRJobConfig.OUTPUT + "/spill"2 3 + spillNumber + ".out", size, getConf()); Step 3: Sort the

set at this time, such as python MRWordCounter. py-r inline input1 input2 input3. Use the python MRWordCounter. py-r inline input1 input2 input3> out command to output the results of processing multiple files to out. Locally simulate hadoop running: python MRWordCounter-r local This will output the result to the output, which must be written. Run on the hadoop cluster: python MRWordCounter-r hadoop 3. mrjob usage The usage of mrjob is comprehensive in its official documents. The most basic pa

bit of a look around the code:intValue = Stream.of (1, 2, 3, 4). Reduce (sum, item), Sum +item); Assert.assertsame (Value,110);/*or use a method reference*/value= Stream.of (1, 2, 3, 4). Reduce (100, integer::sum); In this example 100 is the calculation of the initial value, each time the addition of the calculated value will be passed to the next calculation of the first parameter. Reduce also has two other overloaded methods: Optionalreduce (Binaryoperatoraccumulator): As defined above, no in

partitioned according to their business requirements, for example, saving different types of results in different file medium. Several partitions are set up here, and there will be several reducer to handle the contents of the corresponding partition.After 1.4 partitioning, the data for each partition is sorted, grouped-the sort is sorted from small to large, and after sorting, the value of the option with the same key value is merged. For example, all key-value pairs may existHello 1Hello 1The

a specified routerRouter Password Decrypt for decrypting Cisco's Type 7 passwordRemote TCP Session Reset is used to display the activated connection on each deviceSNMP Brute Force Attack is used to log the router's login passwordSNMP Dictionary Attack used for dictionary to guess the router's login passwordEdit dictionaries for editing dictionariesCATV Tools BarCATV Subscriber modem Details for querying the current working state of the CATV modemCMTS

In a two-way cable TV system, to make reverse transmission work normally, the confluence noise must be reduced. Most of the confluence noise is formed by a space electromagnetic interference string into the reverse system. In a Bidirectional CATV system, cables are one of the most vulnerable components to interference. In order to make the reverse system work normally, four Shielded Cables with High attenuation Shielding must be used. This paper intro

branch network structure, the noise and intrusion interference from the user and the network are at the front end of the cable network, that is, the roots of the network are converged together. For the backhaul channel, the noise components produced by each amplifier are all gathered at the front end of the access network system. This noise component is proportional to the size of the access network system, it is proportional to the number of upstream amplifiers in the same tree network. In add

the development of optical fiber communication from basic to commercial application. Since then, the optical fiber communication technology has continued to develop: from multi-mode to single-mode, and from 0.85um to 1.31 and 1.55um, the transmission rate has increased from dozens to dozens. On the other hand, with the development of technology and the formation of a large-scale industry, the price of optical fiber is constantly decreasing and the application scope is constantly expanding: from

~7mbps. Users can select as neededUpstream and downstream rates.(2) Basic concept of HFC for fiber coaxial cable hybrid networkThe basic structure of HFC in fiber coaxial cable hybrid networkFrom the user access point of view, optical fiber coaxial cable hybrid network (HYBRIDFIBERCOAX,HFC) is a two-way transformation of the CATV network, is the userAn important way to access the Internet via cable TV broadband.Classification of cable modem Cablemodem

+ C-DOCSIS: national standard technology, for China Radio and Television Network, compatible with the original CMTS system. • FTTH: it is still pilot and the CATV access method is unclear. In the FTTH solution, CATV access is divided into three types: Single-fiber three-wave, dual-Fiber Three-wave, and fiber-optic Coaxial Dual-household. Because a single-fiber three-wave adds one WDM module per household,

. "UPC" is less than the "PC", generally used for equipment with special needs, some foreign manufacturers ODF frame internal jump fiber is FC/UPC, mainly for the improvement of ODF equipment own indicators. In addition, the "APC" model is used in radio and television and early CATV, the tail fiber head adopts the end face with dip angle, which can improve the quality of TV signal, mainly because the TV signal is analog light modulation, when the

impact, this is the basic requirements of optical fiber connectors. To a certain extent, optical fiber connectors also affect the reliability and performance of optical transmission systems. Product dimensional precision, repeatability, interchangeability good, reliable and stable. Excellent temperature stability, can be used in optical fiber communication systems, optical data transmission, LAN, fiber optic sensors and optical fiber CATV. Fib

cabling technology for high-rise office building network integrated design. Technical features based on PON technology The PON system consists of optical circuit terminal (OLT), Optical Network Unit (ONU) and optical distribution network (ODN), which uses topological structures with dots to many points. Passive refers to all of the passive devices and optical fibers from Olt to ONU, and does not require any power source equipment. Pon All Optical Network has three networks in one business cap

and B-I iSDN services can meet the common requirements of various telecom services and full service networks (FSN. APON represents the latest development direction of broadband access technology. Currently, it has been applied in the UK, Germany, and so on. It is considered as a better method to implement FTTC and FTTH. The advantage of APON is that it can save the cost of optical fiber and optical equipment, and realize the network transmission between the broadband data service and the

Broadband wireless access technology is worth learning a lot. Here we mainly introduce the DOCSIS-based broadband wireless access technology, from the DOCSIS Protocol release to the current development trend, many related equipment manufacturers use DOCSIS Protocol in their 3.5 GHz MMDS products because DOCSIS uses many mature technologies to support IP services well, it has adapted to the current technological development trend, and has adopted a large number of Integrated Circuits Used in Cabl