For the deployment configured using switching data-source you should first ensure that data-sources are referenced correctly to switch-A or switch-B data-source. You can check this from BCC > Admin Console > Overview > Production > Agents > Switchable Data Stores. A deployment can get stuck due to snapshot mismatch and in such cases you would have to initialize the snapshot again from dyn/admin. Refer this:
In some situations, a stuck deployment will not allow other deployments to proceed and looks like this is what is happening in your case. Try cleaning the epub_deployment table and deleting the project and then reinitialize your agent/deployments. Also check in the das_deployment table to find if there is any record in it and if it has then what values does it have for the status and current_phase columns.
There may be two reasons
1. Switching Data source
Check Nithin Statement.
2. Snapshot issue,
Look at snapshot id for defined agents,
If snapshot id is null or empty, u need to force the snapshot.
To do this, Search for 'VersionManager' component in merch server, get the latest snapshot id by using below query,
<query-items item-descriptor="snapshot"> ALL ORDER BY ID desc</query-items>
and force it in following component,
Go to "/atg/epub/DeploymentServer" component and force the latest snapshotId.