Mumakombiyuta hardware nemapurogiramu, kuwanikwa kunoreva huwandu hwe "uptime" hwegadziriro (kana zvimwe zvikamu zvehurongwa). Somuenzaniso, kombiyuta yega inogona kuonekwa "inowanikwa" yekushandiswa kana inoshandiswa kwayo inoderedzwa uye inoshanda.
Kunyange zvazvo yakabatana nekuwanikwa, pfungwa yekuvimbika inoreva chimwe chinhu chakasiyana. Kuvimbika kunoreva kukanganisa kwakawanda kwekukundikana kunowanikwa mumamiriro ezvinhu. Nzira yakakwana yakavimbika ichawanawo 100% kuwanikwa, asi kana kukundikana kuchiitika, kuwanika kunogona kugadziriswa nenzira dzakasiyana zvichienderana nehutano hwechinetso.
Basa rekubatira rinobata kuwanikwa pamwe chete. Munyika inoshanda, kukanganisa kunogona kuonekwa uye kunogadziriswa nekukurumidza zvakanyanya kupfuura mune imwe nzira isingakwanisi, iyo inoreva kuderera nguva shoma pane chimwe chiitiko pamwero.
Kuwanikwa Mazinga
Nzira yakananga yekutsanangura mazinga kana makirasi ekuwanika mune kombiyuta network network ndiyo "mukana wemiti." Semuenzaniso, 99% kupedza nguva inoshandura kune maini maviri ekuwanikwa, 99.9% kupedzisira kusvika kune nhatu nhatu, nezvimwe zvakadaro. Tafura inoratidzwa papeji ino inoratidza zvinoreva chiyero ichi. Inoratidzira imwe neimwe yepamusoro maererano nehuwandu hwehuwandu hwenhepfenyuro ye (nonleap) gore inogona kubvumirwa kuti iwane nguva yekukwanisa. Inonyorawo mienzaniso mishomanana yemhando yehurongwa huri kuvakwa iyo inowanzoenderana nezvinodiwa.
Paunenge uchitaura nezvehutachiwana hwehutachiwana, ona kuti nguva yakawanda yakabatanidzwa (masvondo, mwedzi, makore, etc.) inofanira kutsanangurwa kuti ipe chinangwa chakasimba. Chigadzirwa chinowedzera 99.9% uptime pamakore emakore kana kupfuura chakazviratidza pachako kune yakawanda kupfuura imwe iyo kuwanika kwave kuchienzaniswa kwevhiki shomanana.
Network Availability: An Example
Kuwanika kwagara kuchive chinhu chinokosha chemasangano asi chinova chinotonyanya kukosha uye chakaoma pamakwikwi. Nemaitiro avo, mitambo yenhare inowanzoparadzirwa mumakombiyuta akawanda uye inogona kuvimba nedzimwe nzira dzakasiyana-siyana dzakabatsira.
Tora Domain Name System (DNS) , somuenzaniso - inoshandiswa paInternet uye dzakawanda dzepanet network dzedunhu rega kuti dzichengetedze mazita emakombiyuta emakombiyuta zvichienderana nekeroti dzavo. DNS inochengetedza rondedzero yemazita neateri pane seva inonzi primary DNS server . Apo imwe chete DNS server inogadziriswa, server crash inotora pasi DNS dzose pane iyo network. DNS, zvisinei, inopa kutsigirwa kwemaseva akaparadzirwa. Kunze kweiyo primary server, mutungamiri anogonawo kuisa sevhareji uye yepamusoro masipireji DNS pane network. Iye zvino, kukundikana mune imwe yehutatu hutatu hahukwanise kukonzera kurasikirwa kwakakwana kweDNS service.
Sevha inoputika parutivi, mamwe maitiro emagetsi anowanikwawo anoitawo DNS kuwanikwa. Gadzira kusakundika, somuenzaniso, inogona kutora zvakanaka DNS kuburikidza nekuita kuti zvibvirire kuti vatengi vataure neDNS server. Hazvisi zvisinganzwisisiki mumamiriro ezvinhu aya kune vamwe vanhu (zvichienderana nenzvimbo yavo chaiyo pamutambo) kuti varasikirwa neDNS kuwana asi vamwe kuti varambe vasina hanya. Kugadziridza mavhareji akawanda eDNS kunobatsirawo kutarisana nekukundikana kwekunze kusina kukanganisa kunogona kukwanisa kuwanikwa.
Inonzwisisika Kuwanikidzwa uye High Availability
Zvikamu hazvisi zvose zvakasikwa zvakaenzana: Nguva yekukundikana inoitawo basa guru mukuona kwekuwanika kwenhare. Bhizinesi rinotambura rinowanzosvika pakupera kwevhiki, semuenzaniso, rinogona kuratidza kuwanikwa kushoma kwenhamba nhamba, asi nguva iyi inogona kunge isingatomboonekwi nevashandi vese vanogara. Indaneti inoshandisa mitambo inoshandisa izwi refu kuwanikidzwa kwekutarisa kune zvigadzirwa uye zvigadzirwa zvemichina zvakanyanyogadziriswa kuvimbika, kuwanikwa, uye kushanda. Zvirongwa zvakadaro zvinowanzobatanidza zvigadzirwa zvehuwandu ( semuenzaniso , disks uye magetsi) uye software dzakangwara ( semuenzaniso , kuenzanisa mutoro uye kukundikana-pamusoro pemabasa). Dambudziko rekuwana kukwanika kwepamusoro kunowedzera zvinoshamisa pamatanho mana neanomwe-nines, saka vatengesi vanogona kutengesa mari yepamutengo yezvinhu izvi.