# Amazon EMR WAL workspaces
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Amazon EMR WAL adds the concept of WAL workspaces. A *WAL workspace* is a logical container of WALs. Each write-ahead log in Amazon EMR WAL is encapsulated by a WAL workspace. An EMR cluster writes WALs to exactly one WAL workspace that you configure at cluster launch, or to the `defaultWALworkspace` if you don't specify a workspace. WAL workspaces are not related to any existing HBase terminologies such as namespaces.

You can use WAL workspaces to scope down Amazon EMR WAL IAM permissions to only include the workspaces that the cluster needs to access. You can also tag your WAL workspace for tag-based access control. For more information on tagging, see [Tagging WAL workspaces](emr-hbase-wal-tagging.md).

![\[HBase architecture diagram showing write request flow through RegionServers, MemStore, and data storage.\]](http://docs.aws.amazon.com/emr/latest/ReleaseGuide/images/wal-new.png)