Cumulative Update 6 for SQL Server 2017

This article describes Cumulative Update package 6 (CU6) for SQL Server 2017. This update contains fixes that were released after the initial release of SQL Server 2017 and updates the SQL Server and Analysis services components to the following builds:

IMPORTANT

All distributions (including RHEL 7.3 and 7.4) that use the latest available Pacemaker package 1.1.18-11.el7 introduce a behavior change for the start-failure-is-fatal cluster setting when its value is false. This change affects the failover workflow. If a primary replica experiences an outage, the cluster is expected to failover to one of the available secondary replicas. Instead, users will notice that the cluster keeps trying to start the failed primary replica. If that primary never comes online (because of a permanent outage), the cluster never fails over to another available secondary replica.

This issue affects all SQL Server versions, regardless of the cumulative update version that they are on.

To mitigate the issue, use either of the following methods.

Method 1

Follow these steps:

1. Remove the start-failure-is-fatal override from the existing cluster. 

      # RHEL, Ubuntu         pcs property unset start-failure-is-fatal         # or         pcs property set start-failure-is-fatal=true   # SLES         crm configure property start-failure-is-fatal=true

2. Decrease the cluster-recheck-interval value. 

      # RHEL, Ubuntu         pcs property set cluster-recheck-interval=<Xmin>   # SLES         crm configure property cluster-recheck-interval=<Xmin>

3. Add the failure-timeout meta property to each AG resource. 

      # RHEL, Ubuntu         pcs resource update ag1 meta failure-timeout=60s   # SLES         crm configure edit ag1      # In the text editor, add `meta failure-timeout=60s` after any `param`s and before any `op`s

    

   Note In this code, substitute the value for <Xmin> as appropriate. If a replica goes down, the cluster tries to restart the replica at an interval that is bound by the failure-timeout value and the cluster-recheck-interval value. For example, if failure-timeout is set to 60 seconds and cluster-recheck-interval is set to 120 seconds, the restart is tried at an interval that is greater than 60 seconds but less than 120 seconds. We recommend that you set failure-timeout to 60s and cluster-recheck-interval to a value that is greater than 60 seconds. Setting cluster-recheck-interval to a small value is not recommended. For more information, refer to the Pacemaker documentation or consult the system provider. 

Method 2

Revert to Pacemaker version 1.1.16.
 

Cumulative update

To update Linux to the latest CU, you must first have the Cumulative Update repository configured. Then, update your SQL Server packages by using the appropriate platform-specific update command.

For installation instructions and direct links to the CU package downloads, see the Release notes.

IMPORTANT

If you use the Query Store feature, and you have previously installed Cumulative Update 2 (CU2) (14.0.3008.27), the following requirement applies to you:

After you install Cumulative Update 3 (CU3) (14.0.3015.40) or a later CU, you must immediately run the following script to delete all plans that were collected by Query Store while CU2 was installed:

SET NOCOUNT ON;DROP TABLE IF EXISTS #tmpUserDBs;SELECT [database_id], 0 AS [IsDone]INTO #tmpUserDBsFROM master.sys.databasesWHERE [database_id] > 4 AND [state] = 0 -- must be ONLINE AND is_read_only = 0 -- cannot be READ_ONLY AND [database_id] NOT IN (SELECT dr.database_id FROM sys.dm_hadr_database_replica_states dr -- Except all local Always On secondary replicas  INNER JOIN sys.dm_hadr_availability_replica_states rs ON dr.group_id = rs.group_id  INNER JOIN sys.databases d ON dr.database_id = d.database_id  WHERE rs.role = 2 -- Is Secondary   AND dr.is_local = 1   AND rs.is_local = 1)DECLARE @userDB sysname;WHILE (SELECT COUNT([database_id]) FROM #tmpUserDBs WHERE [IsDone] = 0) > 0BEGIN SELECT TOP 1 @userDB = DB_NAME([database_id]) FROM #tmpUserDBs WHERE [IsDone] = 0 -- PRINT 'Working on database ' + @userDB EXEC ('USE [' + @userDB + '];DECLARE @clearPlan bigint, @clearQry bigint;IF EXISTS (SELECT [actual_state] FROM sys.database_query_store_options WHERE [actual_state] IN (1,2))BEGIN IF EXISTS (SELECT plan_id FROM sys.query_store_plan WHERE engine_version = ''14.0.3008.27'') BEGIN  DROP TABLE IF EXISTS #tmpclearPlans;  SELECT plan_id, query_id, 0 AS [IsDone]  INTO #tmpclearPlans  FROM sys.query_store_plan WHERE engine_version = ''14.0.3008.27''  WHILE (SELECT COUNT(plan_id) FROM #tmpclearPlans WHERE [IsDone] = 0) > 0  BEGIN   SELECT TOP 1 @clearPlan = plan_id, @clearQry = query_id FROM #tmpclearPlans WHERE [IsDone] = 0   EXECUTE sys.sp_query_store_unforce_plan @clearQry, @clearPlan;   EXECUTE sys.sp_query_store_remove_plan @clearPlan;   UPDATE #tmpclearPlans   SET [IsDone] = 1   WHERE plan_id = @clearPlan AND query_id = @clearQry  END;  PRINT ''- Cleared possibly affected plans in database [' + @userDB + ']'' END ELSE BEGIN  PRINT ''- No affected plans in database [' + @userDB + ']'' ENDENDELSEBEGIN PRINT ''- Query Store not enabled in database [' + @userDB + ']''END')  UPDATE #tmpUserDBs  SET [IsDone] = 1  WHERE [database_id] = DB_ID(@userDB)END