"Always On" has a space in it

Author: rwestMSFT

azure-sql/virtual-machines/windows/availability-group-manually-configure-multi-subnet-multiple-regions.md

@@ -1,31 +1,35 @@
 ---
-title: "Use contained databases with availability groups"
+title: "Use Contained Databases with Availability Groups"
 description: "Learn about the using a contained database with Always On availability groups in SQL Server 2019 (15.x)."
 author: MashaMSFT
 ms.author: mathoma
-ms.date: "05/17/2016"
+ms.reviewer: randolphwest
+ms.date: 02/04/2026
 ms.service: sql
 ms.subservice: availability-groups
 ms.topic: how-to
 helpviewer_keywords:
   - "Availability Groups [SQL Server], interoperability"
   - "contained database, AlwaysOnAvailabilityGroups"
+  - "contained database, Always On Availability Groups"
 ---
-# Use contained databases with Always On availability groups 
+# Use contained databases with Always On availability groups
+
 [!INCLUDE [SQL Server](../../../includes/applies-to-version/sqlserver.md)]
 
-  This topic contains information about the using a contained database with [!INCLUDE[ssHADR](../../../includes/sshadr-md.md)] in [!INCLUDE[ssnoversion](../../../includes/ssnoversion-md.md)].  
-  
-##  <a name="Prerequisites"></a> Prerequisites  
-  
--   Before adding a contained database to an availability group, ensure that the **contained database authentication** server option is set to **1** on every server instance that hosts an availability replica for the availability group. For more information, see [contained database authentication Server Configuration Option](../../../database-engine/configure-windows/contained-database-authentication-server-configuration-option.md) and [Server Configuration Options &#40;SQL Server&#41;](../../../database-engine/configure-windows/server-configuration-options-sql-server.md).  
-  
-##  <a name="RelatedTasks"></a> Related Tasks  
-  
--   [Server Configuration Options &#40;SQL Server&#41;](../../../database-engine/configure-windows/server-configuration-options-sql-server.md)  
-  
-## See Also  
- [Overview of Always On Availability Groups &#40;SQL Server&#41;](../../../database-engine/availability-groups/windows/overview-of-always-on-availability-groups-sql-server.md)   
- [Contained Databases](../../../relational-databases/databases/contained-databases.md)  
-  
-  
+This article contains information about the using a contained database with [!INCLUDE [ssHADR](../../../includes/sshadr-md.md)] in [!INCLUDE [ssnoversion](../../../includes/ssnoversion-md.md)].
+
+## Prerequisites
+
+Before adding a contained database to an availability group, ensure that the `contained database authentication` server configuration option is set to `1` on every server instance that hosts an availability replica for the availability group.
+
+For more information, see [Server Configuration: contained database authentication](../../configure-windows/contained-database-authentication-server-configuration-option.md).
+
+## Related tasks
+
+- [Server configuration options](../../configure-windows/server-configuration-options-sql-server.md)
+
+## Related content
+
+- [What is an Always On availability group?](overview-of-always-on-availability-groups-sql-server.md)
+- [Contained Databases](../../../relational-databases/databases/contained-databases.md)

azure-sql/virtual-machines/windows/availability-group-manually-configure-multiple-regions.md

@@ -4,7 +4,7 @@ description: How to configure a SQL Server Always On availability group using cu
 author: rwestMSFT
 ms.author: randolphwest
 ms.reviewer: atsingh, amitkh-msft
-ms.date: 01/13/2026
+ms.date: 02/04/2026
 ms.service: sql
 ms.subservice: linux
 ms.topic: design-pattern
@@ -47,7 +47,7 @@ This article explains how to configure a SQL Server Always On availability group
 
 Create the AG. Set `CLUSTER_TYPE = EXTERNAL`. In addition, set each replica with `FAILOVER_MODE = EXTERNAL`. Depending on the environment's requirements, set `AVAILABILITY_MODE` to either `SYNCHRONOUS_COMMIT` or `ASYNCHRONOUS_COMMIT.`
 
-**Paxos protocol** plays a critical role in the internal communication and configuration consistency of AlwaysOn availability groups (AGs) in SQL Server, particularly in cluster-agnostic or external cluster configurations. Paxos maintains consistency of the AG configuration across replicas, prevent split-brain scenarios, and ensures only primary is responsible for configuration updates.
+**Paxos protocol** plays a critical role in the internal communication and configuration consistency of Always On availability groups (AGs) in SQL Server, particularly in cluster-agnostic or external cluster configurations. Paxos maintains consistency of the AG configuration across replicas, prevent split-brain scenarios, and ensures only primary is responsible for configuration updates.
 
 The following Transact-SQL script creates an AG named `ag1`. The script configures the AG replicas with `SEEDING_MODE = MANUAL`. This setting requires you to manually initialize secondary replicas with a copy of the database before adding them to the AG. Update the following script for your environment. Replace the `<node1>`, `<node2>`, and `<node3>` values with the names of the SQL Server instances that host the replicas. This AG also configures the configuration only replica `<node3>`. The configuration only replica maintains configuration information about the availability group in the `master` database but doesn't contain the user databases in the availability group. Replace the `<5022>` value with the port you set for the endpoint. Run the following Transact-SQL script on the primary SQL Server replica:
 
@@ -199,4 +199,4 @@ To force a manual failover with data loss from primary replica N1 to secondary r
 
 - [Distributed availability groups](../../../database-engine/availability-groups/windows/distributed-availability-groups.md)
 - [What is an Always On availability group?](../../../database-engine/availability-groups/windows/overview-of-always-on-availability-groups-sql-server.md)
-- [Perform a forced manual failover of an Always On availability group (SQL Server)](../../../database-engine/availability-groups/windows/perform-a-forced-manual-failover-of-an-availability-group-sql-server.md)
+- [Perform a forced manual failover of an Always On availability group (SQL Server)](../../../database-engine/availability-groups/windows/perform-a-forced-manual-failover-of-an-availability-group-sql-server.md)

docs/database-engine/availability-groups/windows/contained-databases-with-always-on-availability-groups-sql-server.md

@@ -4,7 +4,7 @@ description: "MSSQLSERVER_19407"
 author: pijocoder
 ms.author: jopilov
 ms.reviewer: randolphwest
-ms.date: 04/03/2024
+ms.date: 02/04/2026
 ms.service: sql
 ms.subservice: supportability
 ms.topic: "reference"
@@ -18,7 +18,7 @@ helpviewer_keywords:
 ## Details
 
 | Attribute | Value |
-| :--- | :--- |
+| --- | --- |
 | Product Name | SQL Server |
 | Event ID | 19407 |
 | Event Source | MSSQLSERVER |
@@ -30,7 +30,7 @@ helpviewer_keywords:
 
 Error 19407 is raised in the SQL Server error log when the communication between SQL Server and the Windows Server Failover cluster is lost. Typically a corrective action occurs - a failover to another Always On node.
 
-A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Mechanics and guidelines of lease, cluster, and health check timeouts for Always On availability groups](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server AlwaysOn Lease Timeout](https://techcommunity.microsoft.com/t5/sql-server-support-blog/how-it-works-sql-server-alwayson-lease-timeout/ba-p/317268)
+A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Mechanics and guidelines of lease, cluster, and health check timeouts for Always On availability groups](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server Always On Lease Timeout](https://techcommunity.microsoft.com/blog/sqlserversupport/how-it-works-sql-server-alwayson-lease-timeout/317268).
 
 ### Causes
 
@@ -59,7 +59,7 @@ Since Windows Events are light-weight synchronization objects, there's relativel
 
 1. Go to the **Performance** tab and see if CPUs are close to or at 100% utilization.
 
-1. Go to the **Processes** tab and sort processes by the CPU column in descending order, by selecting on the **CPU** column.
+1. Go to the **Processes** tab and sort processes by the CPU column in descending order, by selecting the **CPU** column.
 
 1. Identify the process that uses most CPU, and work on understanding and resolving the reason for it causing the high CPU.
 
@@ -211,7 +211,7 @@ For more information, see [Use the Sqldumper.exe tool to generate a dump file in
 
 ### Check virtual machine (VM) configuration for overprovisioning
 
-If you're using a virtual machine, ensure that you aren't overprovisioning or overcommitting CPUs and memory resources. Overprovisioning CPUs or memory might cause the guest OS to run out of resources and show the same problems described earlier - high CPU and low memory. Frequently if you're viewing things inside the guest OS, explaining why you're running out of computing resources is difficult, because things are happening outside of the virtual machine itself. Overcommitting resources can cause temporary halts of processing, which are likely to cause lease timeouts. For more information on how to address overcommitting, see [Troubleshooting ESX/ESXi virtual machine performance issues (2001003)](https://kb.vmware.com/s/article/2001003) and [Virtualization – Overcommitting memory and how to detect it within the VM](https://techcommunity.microsoft.com/t5/running-sap-applications-on-the/virtualization-8211-overcommitting-memory-and-how-to-detect-it/ba-p/367623).
+If you're using a virtual machine, ensure that you aren't overprovisioning or overcommitting CPUs and memory resources. Overprovisioning CPUs or memory might cause the guest OS to run out of resources and show the same problems described earlier - high CPU and low memory. Frequently if you're viewing things inside the guest OS, explaining why you're running out of computing resources is difficult, because things are happening outside of the virtual machine itself. Overcommitting resources can cause temporary halts of processing, which are likely to cause lease timeouts. For more information on how to address overcommitting, see [Troubleshooting ESX/ESXi virtual machine performance issues (2001003)](https://kb.vmware.com/s/article/2001003) and [Virtualization - Overcommitting memory and how to detect it within the VM](https://techcommunity.microsoft.com/blog/sapapplications/virtualization-8211-overcommitting-memory-and-how-to-detect-it-within-the-vm/367623).
 
 ### Check for virtual machine (VM) migration or backup
 

docs/linux/business-continuity/high-availability/configure-custom-logic.md

@@ -3,7 +3,8 @@ title: "MSSQLSERVER_19419"
 description: "MSSQLSERVER_19419"
 author: pijocoder
 ms.author: jopilov
-ms.date: 01/13/2023
+ms.reviewer: randolphwest
+ms.date: 02/04/2026
 ms.service: sql
 ms.subservice: supportability
 ms.topic: "reference"
@@ -17,7 +18,7 @@ helpviewer_keywords:
 ## Details
 
 | Attribute | Value |
-| :--- | :--- |
+| --- | --- |
 | Product Name | SQL Server |
 | Event ID | 19419 |
 | Event Source | MSSQLSERVER |
@@ -30,9 +31,9 @@ helpviewer_keywords:
 Error 19419 is raised in the SQL Server error log when the lease worker on the SQL Server side didn't get scheduled in time to process event signal from the cluster.
 Specifically, SQL Server calls [WaitForMultipleObjects()](/windows/win32/api/synchapi/nf-synchapi-waitformultipleobjects) waiting for the Lease timeout event to be set in a signaled state. If the function returns WAIT_OBJECT_0, which indicates success, but by this time the lease has expired, then error 19419 is raised.
 
-A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Lease Mechanism](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server AlwaysOn Lease Timeout](https://techcommunity.microsoft.com/t5/sql-server-support-blog/how-it-works-sql-server-alwayson-lease-timeout/ba-p/317268)
+A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Mechanics and guidelines of lease, cluster, and health check timeouts for Always On availability groups](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server Always On Lease Timeout](https://techcommunity.microsoft.com/blog/sqlserversupport/how-it-works-sql-server-alwayson-lease-timeout/317268).
 
-This error is related to other lease timeout errors and provides more specific detail for error [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md)
+This error is related to other lease timeout errors and provides more specific detail for error [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md).
 
 ### Causes
 
@@ -43,19 +44,18 @@ Since Windows Events are light-weight synchronization objects, there's relativel
 - SQL Server process not responding while generating a large memory dump
 - WSFC going offline (e.g due to quorum loss)
 
-
 The most common reason for error 19419 is high CPU, which causes a delay in scheduling the lease worker thread.
 
 ## User action
 
 Check the CPU utilization on the server as SQL Server lease worker seems to be starved for CPU resources. The following PowerShell script will allow you to quickly diagnose CPU usage on the system.
 
- ```powershell
+```powershell
   Get-Counter -Counter "\Processor(_Total)\% Processor Time" -SampleInterval 5 -MaxSamples 30 |
     Select-Object -ExpandProperty CounterSamples | Select-Object TimeStamp, Path, CookedValue
   ```
 
-For detailed troubleshooting, see User action in [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md#user-action)
+For detailed troubleshooting, see User action in [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md#user-action):
 
 - Troubleshoot high CPU issues
 - Troubleshoot low memory issues

docs/relational-databases/errors-events/mssqlserver-19407-database-engine-error.md

@@ -3,7 +3,8 @@ title: "MSSQLSERVER_19421"
 description: "MSSQLSERVER_19421"
 author: pijocoder
 ms.author: jopilov
-ms.date: 01/13/2023
+ms.reviewer: randolphwest
+ms.date: 02/04/2026
 ms.service: sql
 ms.subservice: supportability
 ms.topic: "reference"
@@ -17,7 +18,7 @@ helpviewer_keywords:
 ## Details
 
 | Attribute | Value |
-| :--- | :--- |
+| --- | --- |
 | Product Name | SQL Server |
 | Event ID | 19421 |
 | Event Source | MSSQLSERVER |
@@ -29,9 +30,9 @@ helpviewer_keywords:
 
 Error 19421 is raised in the SQL Server error log when the lease helper on the Windows cluster side didn't signal the SQL Server lease worker thread within the pre-defined lease period. Specifically, SQL Server calls [WaitForMultipleObjects()](/windows/win32/api/synchapi/nf-synchapi-waitformultipleobjects) waiting for the Lease timeout event to be set in a signaled state. If the function returns WAIT_TIMEOUT, because it has exceeded the specified Lease interval, then error 19421 is raised.
 
-A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Lease Mechanism](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server AlwaysOn Lease Timeout](https://techcommunity.microsoft.com/t5/sql-server-support-blog/how-it-works-sql-server-alwayson-lease-timeout/ba-p/317268)
+A lease is a time-based communication mechanism that takes place between the SQL Server and the Windows Server Failover Cluster (WSFC) process, specifically the RHS.EXE process. The two processes communicate with each other periodically to ensure the other process is running and responding. This communication takes place using Windows [Event objects](/windows/win32/sync/event-objects) and ensures that a failover of the AG resource doesn't occur without the knowledge of the WSFC. If one of the processes doesn't respond to the lease communication based on a predefined lease period, a lease timeout occurs. For detailed information, see [Mechanics and guidelines of lease, cluster, and health check timeouts for Always On availability groups](../../database-engine/availability-groups/windows/availability-group-lease-healthcheck-timeout.md). Also see [How It Works: SQL Server Always On Lease Timeout](https://techcommunity.microsoft.com/blog/sqlserversupport/how-it-works-sql-server-alwayson-lease-timeout/317268).
 
-This error is related to other lease timeout errors and provides more specific detail for error [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md)
+This error is related to other lease timeout errors and provides more specific detail for error [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md).
 
 ### Causes
 
@@ -46,7 +47,7 @@ Since Windows Events are light-weight synchronization objects, there's relativel
 
 Check corresponding Availability Group resource in WSFC cluster to see if it reported any errors.
 
-For detailed troubleshooting, see User action in [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md#user-action)
+For detailed troubleshooting, see User action in [MSSQLSERVER_19407](mssqlserver-19407-database-engine-error.md#user-action):
 
 - Troubleshoot high CPU issues
 - Troubleshoot low memory issues