An ƙera Nagor algorithm na injiniya na Nagle, mai suna David Nagle, wanda aka sanya shi don rage ragewar cibiyar sadarwa ta hanyar "ƙananan matsaloli" tare da aikace-aikacen TCP . Ƙungiyoyin UNIX sun fara amfani da algorithm na Nagle a cikin shekarun 1980, kuma ya kasance abin da ke daidai na TCP a yau.
Ta yaya Nagle Algorithm ke aiki?
Nagle ta algorithm bayanai game da aika da gefe na aikace-aikacen TCP ta hanyar da ake kira nagling . Yana gano saƙonnin ƙananan saƙonni kuma yana tara su a cikin saitunan TCP mafi girma kafin aika bayanai a fadin waya, saboda haka ya guje wa tsarawar ƙananan lambobi marasa amfani. Bayanin fasaha na Nagle's algorithm aka buga a 1984 a matsayin RFC 896. Hanyoyin yanke shawara don yawan bayanai don tarawa kuma tsawon lokacin da za a jira a tsakanin aikawa yana da mahimmanci ga cikakken aikinsa.
Nagling zai iya yin amfani da ƙarfi ta hanyar sadarwa ta hanyar sadarwa ta hanyar haɓaka jinkirin ( latency ). Misali da aka bayyana a cikin RFC 896 ya nuna alamar amfani da bandwidth da kuma dalilin dalilinsa:
- TCP aikace-aikacen da ke tsaida keyboard keystrokes kuma yana so ya sadarwa kowace hali da ake buga zuwa mai karɓa, iya samar da jerin sakonni kowane dauke da 1 byte na bayanai.
- Kafin waɗannan sakonni za a iya aikawa a fadin hanyar sadarwa, dole ne a kunshe kowannensu tare da bayanin bayanan TCP kamar yadda TCP / IP ta buƙata. Kowane jigogi yana cikin girman tsakanin 20 zuwa 60 bytes.
- Ba tare da jigilar ba, wannan aikace-aikacen aikace-aikacen zai samar da sakonnin sadarwa wanda ya ƙunshi 95% ko fiye da bayanin kaiwa (akalla 20 daga 21 bytes) da 5% ko ƙasa da ainihin bayanai daga keyboard ɗin mai aikawa. Amfani da Nagor algorithm, ana iya samun wannan bayanai ta amfani da saƙonnin da yawa kuma yana da kashi 95 cikin 100 na abubuwan ciki shine bayanin kundin bayanai - babban kudade na bandwidth.
Aikace-aikace sun mallaki amfani da su na Nagle algorithm tare da zaɓi na shirye-shirye na TCP_NODELAY. Windows, Linux, da kuma tsarin Java duk suna ba da damar Nagle ta hanyar tsoho, don haka aikace-aikacen da aka rubuta don waɗannan wurare yana buƙatar saka TCP_NODELAY lokacin da kake son canzawa algorithm.
Ƙuntatawa
Nagor's algorithm kawai amfani da TCP. Sauran ladabi da suka hada da UDP ba su goyi bayan shi ba.
TCP aikace-aikace da ke buƙatar amsawar cibiyar sadarwa mai sauri, kamar kiran wayar Intanit ko wasan kwaikwayo na farko, bazai yi aiki ba yayin da Nagle ya kunna. Lokacin jinkirin da aka yi yayin algorithm yana ɗaukan karin lokaci don tara ƙananan bayanai na bayanai tare zasu iya faɗakar da lag a hankali a kan allon ko a cikin tashar sauti na dijital. Wadannan aikace-aikacen suna musayar Nagle da yawa.
Wannan algorithm an samo asali ne a lokacin da cibiyar sadarwar yanar gizo ta goyi bayan goyon bayan kwamfutarka fiye da yadda suke yi a yau. Misalin da aka bayyana a sama ya dogara ne akan abubuwan da John Nagle ya samu a kamfanin Ford Aerospace a farkon shekarun 1980, inda yunkurin cinikayya a kan jinkirta, cibiyar sadarwa mai nisa da yawa ya yi kyau. Akwai ƙananan yanayi inda aikace-aikace na cibiyar sadarwa zasu iya amfana daga algorithm a yau.