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Geo-Replications Types in SQL Azure

שלום לכולם וחורף נעים
והיום דווקא לא על V12...
היום על DR.
ישנן 2 אפשרויות לרפלק את בסיסי הנתונים שלנו עבור DR:

  • Standard Geo-replication
  • Active Geo-replication
לפני שאסביר בקצרה על ההבדלים - יש לשים לב שבכל רגע נתון אפשר לעצור רפליקציה ולשחרר את בסיס הנתונים המשני ובכך לאפשר  Fail Over.

ההבדלים בין אפשרויות אלו מתחלקים לכמה נושאים והנה תקציר קצר שלהם:

Standard Geo-replication Active Geo-replication
  • Not Readable
  •  Readable
  • Azure choose the target location
  • Any location you can choose
  • Only 1 replication
  • Up to 4 replications
  • Fail Over rules by MSFT
  • Manually failing over a database
  • 75% of DB cost
  • Full DB Cost

מספר נקודות להבהרה:
  • אי אפשר לבדוק בצורה אמיתית fail over כי בזמן הבדיקה בסיס הנתונים של הייצור - חשוף ללא dr. כי בזמן הניתוק יש בעיה.
  • הרפליקציה היא א-סינכורנית.
  • הפסקת רפליקציה יכולה להתבצע מהמאסטר או מהרפליקות - אם היא מתבצעת מהרפליקות היא מתבצעת מיידית כלומר ייתכן מידע שיילך לאיבוד. אם היא מהמאסטר אפשר להחליט אם ייכלו לאיבוד טרנקציות.
  • שלא כמו AO שם השרת ברפליקה לא יכול להיות זהה - ולכן במקרה של fail over חייבים לשנות קונפיגורציה.


הנה לינקים קצרים בנושא :

כאשר בלינק הזה יש לפתוח את ההרחבות הבאות:



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