Issue: Deadlock messages in Deploy logs

Pranav Prakash

March 15, 2022 15:01

We sometimes see deadlock messages in the logging:

DELETE FROM SPRING_SESSION WHERE SESSION_ID = ?]

The deployment status is failed but the deployment itself looks good.

Deploy 9.7 and above with MSSQL Database

MS SQL Server does not have Multi-Version Concurrency Control (MVCC) activated by default. Deploy requires this feature to function correctly.

You can enable snapshot isolation mode by executing the following commands on an SQL Server:
```
ALTER DATABASE <database_name> SET ALLOW_SNAPSHOT_ISOLATION ON;
ALTER DATABASE <database_name> SET READ_COMMITTED_SNAPSHOT ON;
```
Also, can you make sure that you have followed the best practices mentioned in our documentation: https://docs.xebialabs.com/v.10.0/deploy/how-to/configure-the-xl-deploy-sql-repository/#best-practices-for-installation-and-schema-creation-for-sql-server
We have noticed this issue with deadlocks in spring-session while using the MSSQL database. It recommended disabling the Active Sessions to prevent deadlocks in the tables.
This can be done by adding the following line in the deployit.conf file.
```
active.user.sessions=false
```