Ezingxenyeni zekhompyutha, i- CDN imele noma yi- Content Delivery Network noma i- Content Distribution Network . I-CDN isistimu yamakhasimende / isiphakeli esasakazwe eklanyelwe ukuthuthukisa ukwethembeka nokusebenza kwezicelo ze-inthanethi.
Umlando we-CDN
Ama-Network Delivery Networks aqala ukuhlelwa njenge- World Wide Web (WWW) yaqhuma ekuthandeni phakathi nawo-1990. Abaholi bezobuchwepheshe baqaphela ukuthi i-intanethi ayikwazanga ukubhekana nezinga elikhulayo lomgwaqo wenethiwekhi ngaphandle kwezindlela ezingaphezulu ezihlakaniphile zokuphatha ukugeleza kwedatha.
Eyasungulwa ngo-1998, u-Akamai Technologies yinkampani yokuqala yokwakha ibhizinisi elikhulu nge-CDN. Abanye balandela impumelelo ehlukahlukene. Kamuva, izinkampanini ezihlukahlukene zokuxhumana zakwa-AT & T, i-Deutsche Telekom, neTelstra zakha ama-CDN awo kanye nawo. Ama-Network Delivery Networks namuhla athatha ingxenye ebalulekile yokuqukethwe kwewebhu, ikakhulukazi amafayela amakhulu afana namavidiyo nokulanda uhlelo lokusebenza. Zombili ama-CDN ezentengiselwano nezengabhizinisi.
Indlela i-CDN isebenza ngayo
Umhlinzeki we-CDN ukufaka amaseva awo ezindaweni eziyinhloko kuwo wonke ama-intanethi. Iseva ngayinye iqukethe isitoreji esikhulu sesitoreji sendawo kanye nekhono lokuvumelanisa amakhophi wedatha yayo namanye amaseva kwinethiwekhi yokuqukethwe ngenqubo ebizwa ngokuthi ukuphindaphinda . Lawa maseva enza njengamakhodi wedatha. Ukuze unikeze idatha egcinwe kumakhasimende emhlabeni jikelele ngokuphumelelayo kakhulu, abahlinzeki be-CDN bafake amaseva abo ezindaweni "ezingenqenqemeni" ezihlakazekile endaweni - izindawo ezixhuma ngqo kwi- backbone ye- intanethi, ikakhulukazi ezindaweni zokuxhumana eziseduze nabanikezeli be-Internet Serivisi enkulu (ISPs) . Abanye abantu bababiza ngokuthi amaphuzu wePoint of Presence (PoP) noma "ama-caches emaphethelweni" ngokufanele.
Umshicileli wokuqukethwe othanda ukusabalalisa idatha yabo nge-CDN ababhalisile nomhlinzeki. Abahlinzeki be-CDN banikeza abamemezeli ukufinyelela kwinethiwekhi yabo yeseva lapho izinguqulo zangempela zezinto zokuqukethwe (ngokuvamile ezifayili noma amaqembu amafayela) zingalayishwa ngokusabalalisa nokugcinwa kwekhompiyutha. Abahlinzeki basekela ama- URL noma izikripthi abashicileli abashume kuzo kumasayithi abo ukuze babhekisele kulezo zinto ezigcinwe okuqukethwe.
Uma amaklayenti e-intanethi (iziphequluli zeWebhu noma izinhlelo zokusebenza ezifanayo) athumela izicelo zokuqukethwe, iseva eyamukelayo yomsakazo iphendula futhi ivuselela izicelo kumaseva we-CDN njengoba kudingeka. Amaseva e-CDN afanelekile akhethwa ukuletha okuqukethwe ngokusho kwendawo yomthengi. I-CDN iletha idatha ngokuseduze komfakisicelo ukunciphisa umzamo odingekayo wokuwudlulisela kuwo wonke ama-intanethi.
Uma iseva ye-CDN iceliwe ukuba ithumele into yokuqukethwe kodwa ingenayo ikhophi, izophinde icele iseva yomzali we-CDN eyodwa. Ngaphezu kokudlulisela ikhophi kumceli, iseva ye-CDN izogcina ikhophi yayo (cache) ikhophi yayo ukuze izicelo ezilandelayo zento efanayo zingagcwaliswa ngaphandle kokudinga ukubuza umzali futhi. Izinto zikhishwa esitokisini noma ngabe iseva idinga ukukhulula isikhala (inqubo ebizwa ngokuthi ukuxoshwa ) noma uma into ingakacelwa isikhathi esithile (inqubo ebizwa ngokuthi ukuguga ).
Izinzuzo zokuThuthukiswa koKwenethiwekhi
Ama-CDN abahlinzeki abazuzisayo ngokuhlanganyela, abashicileli bokuqukethwe, namakhasimende (abasebenzisi) ngezindlela eziningana:
- Abanikezeli abakhulu abanjengo-Akamai benze amabhizinisi ahlomulayo avela kuma-CDN, kodwa amafemu amancane aphumelele futhi. Lezi zinhlelo ezisetshenzisiwe zisiza ukunciphisa ukulayisha jikelele emhlabeni jikelele, okwenza iWeb isebenze ngokuphumelelayo kuwo wonke umuntu.
- Ama-CDN angathuthukisa izinga lomshicileli lomsebenzi. Ngokwenza ukuxhumana kwabo kuphendule ngokwengeziwe nokuqukethwe okusheshayo ukulanda, abamemezeli bakhulisa ukwaneliseka kwamakhasimende abo (futhi bavame ukuheha amakhasimende amaningi).
- Abasebenzisi beklayenti bajabulela ukulandwa okusheshayo kokuqukethwe okunikwe amandla kwe-CDN njengamavidyo kanye nokuphendula okungcono okungcono ( ukuvinjelwa kwenethiwekhi ephansi , izikhathi zokuhamba ezifishane) zezinhlelo zokusebenza ze-inthanethi.
Izinkinga ezine-CDN
Abahlinzeki be-CDN bavame ukukhokha amakhasimende abo ngokusho komthamo we-network ngamunye owenza ngezicelo zabo nezinsiza zabo. Imali ingabuthelela ngokushesha, ikakhulukazi uma amakhasimende abhalisela izinhlelo zesevisi ezithintekayo futhi adlulise umkhawulo wabo. Izimpikane zomshuwalense ezingalindelekile ezibangelwa imicimbi yezenhlalakahle nezezindaba ezingenakulungiswa, noma ngezinye izikhathi ngisho nokuhlaselwa kweDenal of Service (DoS) , kungaba yinkinga ngokukhethekile.
Ukusebenzisa i-CDN kwandisa ukushicilelwa komshicileli wokuqukethwe kumabhizinisi wesithathu. Uma umhlinzeki ehlangabezana nezinkinga zezobuchwepheshe nengqalasizinda yayo, abasebenzisi bangase babhekane nezinkinga ezibalulekile zokusakaza ezifana nokusakazwa kwevidiyo okulula noma isikhathi sokuxhumana senethiwekhi. Abanikazi bezakhi zokuqukethwe bangathola izikhalazo njengamakhasimende ekupheleni ngokuvamile abangezi ngama-CDN.