Exclude tidb_binlog & other reserved database names out-of-box

[sokada1221]

Feature Request

Is your feature request related to a problem? Please describe:

For the database migration that we're performing, we setup DM from Aurora to TiDB first. Then after the migration, we'll revert the replication to replicate from TiDB to Aurora using drainer.

As we switch the replication direction back and forth, we hit an issue where manual changes to tidb_binlog database propagate and break the replication.

Describe the feature you'd like:

In general, any reserved database names for TiDB tools should be excluded from replication pipeline out-of-box.

For instance, in addition to tidb_binlog, I can quickly think of the following:

• dm_meta
• sync_diff_inspector
• tidb_loader

If we get a consensus on this, I think we can apply the same default rule to other replication tools too (e.g. DM).

Describe alternatives you've considered:

• Manually add tidb_binlog to the ignore-schemas configuration

Teachability, Documentation, Adoption, Migration Strategy:

N/A

[july2993]

SGTM @csuzhangxc @GregoryIan PTAL and maybe we should better use some common pattern name for such reserved database.

[csuzhangxc]

How about choosing a schema for all TiDB tools as another system schema? But this may break the compatibility.

[july2993]

How about choosing a schema for all TiDB tools as another system schema? But this may break the compatibility.

using some agreed name like tidb_tool should be good for the later tools(if we have), it's ok to keep the existing tools with the current names?