Ndalama ya Nagle , yomwe inatchulidwa ndi injiniya John Nagle, inakonzedwa kuti ichepetse kugwirizanitsa makompyuta chifukwa cha "mavuto ang'onoang'ono a phukusi" ndi ntchito za TCP . Zotsatira za UNIX zinayamba kugwiritsa ntchito njira ya Nagle m'ma 1980, ndipo imakhalabe yeniyeni ya TCP lero.
Momwe Algorithm Yachikhalire imagwirira ntchito
Ndondomeko ya Nagle ya ndondomeko ya deta pamatumizidwe a TCP ntchito ndi njira yotchedwa kugwedeza . Zimatumiza mauthenga aang'ono ndikuziika mu mapaketi akuluakulu a TCP musanawatumize deta kudutsa waya, motero kupewa kupezeka kwa mapepala ang'onoang'ono osayenera. Chidziwitso cha katswiri wa Nagle chinasindikizidwa mu 1984 monga RFC 896. Zosankha kuti deta yambiri ikhalepo komanso momwe angayembekezere pakati pa kutumizidwa ndizofunikira kwambiri kuntchito yake yonse.
Nagling angagwiritse ntchito mosagwiritsira ntchito chiwongolero cha mgwirizano wa Intaneti pokhapokha kuwonjezereka kuchedwa ( latency ). Chitsanzo chofotokozedwa mu RFC 896 chikuwonetseratu zopindulitsa zomwe zingapindule ndi bandwidth ndi chifukwa cha chilengedwe chake:
- Pulogalamu ya TCP yomwe imapangitsa makina osokoneza makina ndipo imafuna kulumikiza chikhalidwe chilichonse choyimiridwa ndi wolandila, ikhoza kupanga mauthenga angapo omwe ali ndi 1 ochepera deta.
- Musanatumizire mauthengawa pa intaneti, aliyense ayenera kuikidwa pamodzi ndi mauthenga a TCP monga mutu wa TCP / IP. Mutu uliwonse umakhala wofanana pakati pa 20 ndi 60 bytes.
- Popanda kusinthana, chitsanzo chachitsanzo ichi chidzapanga mauthenga a mauthenga omwe ali ndi 95% kapena zina zambiri za mutu wa mutu (zosachepera 20 pa 21 ndi data) 5% kapena zosachepera kwenikweni kuchokera ku makina a wotumiza. Pogwiritsira ntchito ndondomeko ya Nagle, deta yomweyi ingathe kuperekedwa kudzera mu mauthenga ambiri ochepa komanso kukhala ndi 95% ya zomwe zilikhiridwe zowonjezereka - lalikulu kwambiri la ndalama zogwiritsira ntchito bandwidth.
Mapulogalamu amayendetsa ntchito yawo ya kusintha kwa Nagle ndi chochita cha TCP_NODELAY chojambulira chingwe . Mawindo a Windows, Linux, ndi Java zonse zimathandiza kuti mugwirizanitse ndi kusakhulupirika, kotero mapulogalamu olembedwera kumalo amenewo ayenera kufotokoza TCP_NODELAY pofuna kusintha kusinthika.
Zolepheretsa
Nzeru za Nagle zimagwiritsidwa ntchito ndi TCP. Malamulo ena kuphatikizapo UDP samachirikiza .
Mapulogalamu a TCP omwe amafunika kuyankhidwa mwachangu, monga kuyitana mafoni pa intaneti kapena masewera othamanga, sangagwire bwino pamene Nagle athandizidwa. Kuchedwa kumene kunayambika pamene kusintha kwake kumatenga nthaŵi yowonjezera kuti asonkhanitse zigawo zing'onozing'ono za deta pamodzi kungayambitse zizindikiro zooneka bwino pawindo kapena muwunikira. Mapulogalamu awa amalepheretsa Nagle.
Chokonzekera ichi chinayambitsidwa poyamba pomwe makompyuta amathandizira kwambiri kusiyana kwapakati kuposa momwe akuchitira lero. Chitsanzo chofotokozedwa pamwambachi chinachokera ku zochitika za John Nagle ku Ford Aerospace kumayambiriro kwa zaka za m'ma 1980, kumene malonda omwe ankayenda nawo pang'onopang'ono, omwe ankanyamula mtunda wautali kwambiri anali ozindikira. Pali zochitika zochepa kwambiri momwe mautumiki apakompyuta angapindule ndi momwe amachitira lero.