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AlwaysOn Availability Groups SQL 2012 RRS feed

  • Question

  • I have a client who needs to sync his database over two hot sites.  I am implementing the AlwaysOn Availability Groups for replication.  I have heard that this solution works even over slow internet with high latency.  But I also heard there may be data corruption if latency goes above 30ms.  So that I should at least purchase dark fiber in order to make sure I get the speed and low latency needed to avoid data corruption.  Can someone provide a sited and definitive answer to whether I will be able to set this up using "normal" high speed internet, or if I have special internet needs.  Thanks 
    Thursday, July 16, 2015 5:34 PM

Answers

  • did you already set this up or are you planning to

    because Always on groups require nodes to part of windows cluster group. did you do this step

    Also,  data corruption does not happen due to latency but it can happen for other reasons and in such cases, if you have alwayson, it can be fixed but getting the data\page from the other replicas.

    I think, you implemented Replication and not always on, which should also work fine as long as there is enough to push then transactions quick enough so that they will not get piled up on the publisher - hence less log growth and distribution database growth

    one way to determine this.. check the log generation rate and your bandwidth should able handle that...


    Hope it Helps!!

    Thursday, July 16, 2015 5:46 PM
  • I think using a replication ( merge probably ) will be a good choice... Do you need the secondary servers to be read only or users can insert/delete/update the data as well? 

    http://www.sql-server-performance.com/2005/replication-across-internet/


    Best Regards,Uri Dimant SQL Server MVP, http://sqlblog.com/blogs/uri_dimant/

    MS SQL optimization: MS SQL Development and Optimization
    MS SQL Consulting: Large scale of database and data cleansing
    Remote DBA Services: Improves MS SQL Database Performance
    SQL Server Integration Services: Business Intelligence

    Monday, July 20, 2015 4:42 AM

All replies

  • did you already set this up or are you planning to

    because Always on groups require nodes to part of windows cluster group. did you do this step

    Also,  data corruption does not happen due to latency but it can happen for other reasons and in such cases, if you have alwayson, it can be fixed but getting the data\page from the other replicas.

    I think, you implemented Replication and not always on, which should also work fine as long as there is enough to push then transactions quick enough so that they will not get piled up on the publisher - hence less log growth and distribution database growth

    one way to determine this.. check the log generation rate and your bandwidth should able handle that...


    Hope it Helps!!

    Thursday, July 16, 2015 5:46 PM
  • I think using a replication ( merge probably ) will be a good choice... Do you need the secondary servers to be read only or users can insert/delete/update the data as well? 

    http://www.sql-server-performance.com/2005/replication-across-internet/


    Best Regards,Uri Dimant SQL Server MVP, http://sqlblog.com/blogs/uri_dimant/

    MS SQL optimization: MS SQL Development and Optimization
    MS SQL Consulting: Large scale of database and data cleansing
    Remote DBA Services: Improves MS SQL Database Performance
    SQL Server Integration Services: Business Intelligence

    Monday, July 20, 2015 4:42 AM