Log Indicates MS SQL SERVER is Not Set up For Replication

Question

Greetings,

I observed the following from the logs:

2024-04-23T21:25:20 [SOURCE_CAPTURE ]W: The MS SQL Server instance is not set up for Replication. (sqlserver_log_queries.c:321
2024-04-23T21:25:21 [SOURCE_CAPTURE ]I: Database instance is not enabled for REPLICATION. Enablement is ignore due to internal setup. (sqlserver_log_queries.c:3412)

We have followed the documents below and several other places on how to enable SQL Server as a source of DMS Replications. 
https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.SQLServer.html#CHAP_Source.SQLServer.Prerequisites

The SQL Server Source Endpoints are configured such that (Using MS-CDC not MS-REPLICATION):
1. A nightly backup is scheduled. (native format .BAK).
2. A periodic Transaction Log backup job backup up the tLog every 4 hours (native format .TRN).
3. CDC is enabled on the database
4. Each table in the task table mappings is enabled for CDC with @supports_net_change=1 
5. The recovery model is Full

Other documentation states that either MS-CDC or MS-REPLICATION must be enabled for DMS replication to work. We chose MS-CDC.

Accepted Answer

Thanks for contacting AWS.

Regarding the below messages:

```
2024-04-23T21:25:20 [SOURCE_CAPTURE ]W: The MS SQL Server instance is not set up for Replication. (sqlserver_log_queries.c:321 
2024-04-23T21:25:21 [SOURCE_CAPTURE ]I: Database instance is not enabled for REPLICATION. Enablement is ignore due to internal setup. (sqlserver_log_queries.c:3412)
```

DMS needs either MS-Replication or MS-CDC enabled on SQL server instance. When using self-managed SQL server as source you can exclusively use MS-CDC for ongoing replication without any issues.
By default DMS tries to check if MS-Replication is enabled, if that’s not the case it is going to give you a warning similar to the one you can see in the logs.
These message can be ignored if you have properly enabled MS-CDC on the database and tables as per our public document.
[+] https://docs.aws.amazon.com/dms/latest/userguide/CHAP_Source.SQLServer.html#CHAP_Source.SQLServer.Prerequisites

Also, to avoid this you can use below ECA on source endpoint.
ignoreMsReplicationEnablement=false;

Coming to your other queries:
Is this more of a warning? 
>> Yes, if you have setup MS-CDC then this can be ignored.

Is there going to be any issues with running with MS-CDC only and not enabling MS-REPLICATION?
>> No, there won't be any issues with using MS-CDC.

Answer

I am assuming that you are using SQL Server source which is not on RDS. If it is for RDS SQLServer you can ignore the message.

For non-RDS SQL Server source task would look for MS Replication

To avoid this you can using ECA on source endpoint.

`ignoreMsReplicationEnablement=false;`

Log Indicates MS SQL SERVER is Not Set up For Replication

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