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I. Windows Azure - prezentare generala

In urmatoarele saptamani o sa scriu o serie de posturi despre Windows Azure. O sa prezint pe scurt notiunile generale, impreuna cu exemple unde o sa fie cazul. Postarile nu o sa fie una dupa alta, dar o sa incerc ca macar doua posturi pe saptamana sa fie pe aceasta tema.
Iar acuma sa trecem la subiect.

Ce reprezinta cloud computing? Reprezinta un set de servere interconectare intre ele unde dezvoltatorii pot sa:
  • Instaleze si sa ruleze servicii;
  • Sa stocheze si sa acceseze informatii;
Windows Azure reprezinta o platforma de servicii pentru cloud oferite de catre Microsoft. Aceste servicii sunt oferite prin data centerele din toata lumea, prin intermediul cărora se ofera o metoda simpla, sigura si puternica pentru a crea aplicatii web si servicii.
Windows Azure este un sistem de operare creat special pentru cloud. Este de fapt un Windows 2008 Server fara interfata grafica la care au fost adaugate si alte functionalitati. Ca si o curiozitate, acest sistem de operare poate sa se instaleze si sa porneasca in mai putin de 10 secunde.
Dezvoltatorul poate sa dezvolte intr-un mediu sigur o aplicatie, sa o hosteze si sa faca management pe ea, fara sa isi puna probleme precum ce diferente exista intre sisteme de operare sau modul in care trebuie instalat sistemul de operare.
Daca sunteti curiosi sa vedeti cum arata un data center, va invit sa vizualizati urmatorul filmulet:
How a data center look like.
Beneficiile care le aduce Windows Azure sunt:
  • Scalabilitate instant;
  • Scalabilitate pe orizontala aproape nelimitata;
  • Spatiu de stocare care poate sa fie extins in orice moment;
  • Managment la aplicatie si resurse;
  • Downtime aproape 0 absolut;
  • Low-friction provisioning;
  • Deployment se poate face in orice moment si dureaza doar cateva minute;
  • La deployment in orice moment se poate revenit la versiune anteriora aproape instant;
  • Licentiere soft = 0, nu este nevoie sa cumparati licenta pentru Windows Azure sau SQL Azure;
  • Solutie de racire si de administrare a serverelor;
  • Securitate;
Ce ne ofera Windows Azure:
  • SaaS: Software ca si serviciu;
  • PaaS: Programele ca si serviciu;
  • IaaS: Infrastructura ca si servciu;
Pe scurt, cand folosim Windows Azure platim exact ce folosim in acel moment si atat. De exemplu putem sa platim pentru 3 instante computationale, apoi pentru doua ore sa crestem la 30 de instance, iar apoi sa revenim la 3 instante. O sa platim cele 30 de instante doar pentru cele 2 ore si atat. Prin acest mod, avem o granulatie mult mai fina pentru scalabilitate, putînd sa controlam de la numarul de instante si puterea acestora, ca capacitatea de stocare.
Toate aplicatiile ruleaza independent, iar in cazul in care o instanta cade, ea o sa fie preluata automat de catre o alta instanta, nici un request nu se pierde, iar clientul nu sesizeaza ca s-a intamplat ceva.
Trebuie stiut ca in orice moment, informatia exista in trei copii separate. Fiecare copie este pe o masin diferita, astfel se reduce aproape la minim riscul ca informatia sa se piardă. Doar in cazul unui 11/9 aceste date se pot pierde din nou.
Cand sa folosim Windows Azure? Cand avem nevoie sa dezvoltam o aplicatie pentru nevoile si cerinte zilei de maine, nu de astazi. Nu trebuie doar sa dezvoltam o aplicatie, trebe sa oferim si un mediu unde aplicatia poate sa se extinda si sa creasca.

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