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Will suspended Asynchronous mirroring affect transactional replication RRS feed

  • Question

  • We have
    server in production which is SQL SERVER 2008 R2 and acts as Publisher in
    Transactional Replication(It has two subscription and one Distributor) and at
    the same time it acts as principle in asynchronous mirroring.Yesterday as a test
    we suspended mirorring and we faced with latencies in subscriptions.It seems
    suspension had blocked the submission of transaction logs to
    Subscribers.Interesting point is the mirroring is asynchronous and not
    synchronous. Can suspended mirroring have effect on transactional
    replication?

    A.G

    Friday, June 22, 2012 1:59 PM

Answers

All replies

  • Hi!

    Yes, mirroring can. The reason is that only log records that have been hardened on the mirror partner will be sent over to the replication system. SQL is doing this so that in case of a failover of the mirror your replication doesn't break. (SQL Replication is mirroring aware...) There are ways to work around this issue, but I would be very careful with those..

    Lucifer

    Friday, June 22, 2012 3:13 PM
  • I would appreciate if you give me some direction about those work around ways to solve the issue.


    A.G

    Friday, June 22, 2012 7:48 PM
  • The SQL CAT team has documented this:

    http://download.microsoft.com/download/d/9/4/d948f981-926e-40fa-a026-5bfcf076d9b9/ReplicationAndDBM.docx

    Basically there is a SQL Server Trace Flag to change the behavior of the LogReader. It's TF 1448. If you enable this on the machine running the logreader you will see replication moving ahead even if the transactions are not hardened on the mirror yet.

    • Proposed as answer by amber zhang Monday, June 25, 2012 4:56 AM
    • Marked as answer by amber zhang Friday, June 29, 2012 9:40 AM
    Friday, June 22, 2012 9:32 PM