SQL Saturday #654 - Omaha

Transcription

1 SQL Saturday #654 - Omaha

2 My Top 10+ Favorite Replication Tricks Marcus Hopfinger

3 About me Name: Marcus Hopfinger Job: Database Administrator Company: Daktronics, Inc. ( Duration: Over 16 years working with SQL Server and over eight years working with replication First experience with SQL Server: SQL Server 7

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5 University of Nebraska at Omaha Special thanks to UNO and the College of Business Administration for this awesome facility!

6 Sponsors

7 Trick #1 Replicate from multiple publications to multiple subscriptions

8 A database can have multiple publications Each publication can have multiple subscribers A subscriber can subscribe to multiple publications

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10 Trick #2 Know when to use Snapshot Replication vs. Transactional Replication

11 Snapshot vs Transactional replication Snapshot Need point in time data Relatively small table High volume of transactions You need to perform bulk operations on the table at the publisher (does not mark table as replicated) No primary key requirement Transactional Need near real time data Large table size Low volume of transitions You do not need to perform bulk operations on the table at the publisher (marks the table as replicated) Primary key required

12 Trick #3 Putting data in different schemas and collations at the subscriber than at the publisher

13 Get to know publication properties

14 Get to know publication properties

15 Trick #4 Truncate your subscriber tables rather than drop and recreate them

16 Get to know publication properties

17 Trick #5 Distributing a snapshot as soon as it is available

18 Get to know SQL Agent Default is Create a snapshot immediately and keep the snapshot available to initialize subscriptions However you are likely to want to set a schedule for recurring replication.

19 Get to know SQL Agent Run continuously will distribute the snapshot as soon as created, however distribution always running Defining a schedule involves guess work Run on demand leaves the distribution job unscheduled. I use this one.

20 Get to know SQL Agent Snapshot replication uses two agent jobs. We will modify the Snapshot job.

21 Get to know SQL Agent These are the steps as created by SQL Server. We will add an additional step.

22 Get to know SQL Agent This step will call the distribution job once the step to create the snapshot has completed. The job name value is taken from the distribution job properties. EXEC = 'SQL-SBX-01-T-Chinook-Chinook_snap-SQL-SBX-01-T-7'

23 Get to know SQL Agent Move the new job step to the three position and quits reporting success on success and goes to Detect nonlogged agent shutdown on failure Make sure the Run agent step goes to the next step on success

24 Trick #6 Changing the distribution schedule from continuous to scheduled and vice versa

25 Get to know SQL Agent Transactional replication uses three agent jobs. We will modify the Distribution job.

26 Get to know SQL Agent If going from running continuously to a schedule you will need to stop the distribution job before creating the schedule If going from a schedule to running continuously you will need to manually start the job after making the schedule change

27 Trick #7 Finding your articles

28 This can also be used to check if an article is in more than one publication USE distribution GO SELECT p.publication, a.article FROM dbo.mspublications p JOIN dbo.msarticles a ON p.publication_id = a.publication_id ORDER BY a.article;

29 Trick #8 Painlessly adding articles to your publication

30 EXEC = N = = 'false'; GO EXEC = = = 'false'; GO Must run against publication database before adding article Article must be added using the GUI Snapshot for just the new articles can be generated Reference:

31 However If you set the propertied for All Table Articles it will cause a snapshot of the entire publication to be generated

32 Trick #9 Changing the snapshot location

33 Changing the snapshot location exec = = = 'S:\ReplData\ OR

34 Trick #10 Overcoming version differences

35 Overcoming version differences When replicating from a lower version of SQL Server to a higher version SQL Server will detect a version difference and give you the above warning. You can get around this by creating the subscription from the subscriber, rather than from the publisher, after you have created the publication. Or use SSMS 2016

36 Overcoming version differences Warning the following is not supported by Microsoft However You can replicate from SQL Server 2008 to SQL Server 2016 but seem to have to use a pull subscription. You can replicate from SQL Server 2016 to SQL Server 2008 using either push or pull subscriptions. Just be aware that future updates to either version could break your replication as they won t be tested by Microsoft prior to release. Reference:

37 Trick #11 Crossing domains

38 Crossing domains If you are replicating across domains you can get a few different messages. If you just put the server name without the domain it will tell you the server can t be found. Try to fully qualify the name or use the IP address and it tells you that won t work either. To get around this

39 Crossing domains Create an alias!

40 Crossing domains Additionally, if you don t have trust between the domains you may need to use a SQL Login to connect to the subscriber.

41 Because someone will ask Security Role Requirements for Replication Setup Reference:

42 Because someone will ask Security Role Requirements for Replication Maintenance Reference:

43 Trick #12 Script your publications

44 Script your publications Clean up the publication access of the script removing unneeded access I prefer to comment out the create subscription section and add subscriptions manually For multiple transactional publications you may want to comment all but one create log reader section You can update the script to add new articles or just generate a new script as the publication changes Configured article/publication properties like destination schema will be persisted when scripting your publication

45 Bonus Trick #1 Completely removing replication

46 Completely removing replication EXEC = = tran ;

47 Bonus Tip Replication Monitor is your friend

48 Questions?

49 Contacting me: LinkedIn: Blog: