If your SonarQube instance contains a lot of coding rule violations, the migration process can take very long (up to a few days).
Therefore, it is highly recommended to directly migrate to version 3.7.2 that speeds up this migration process.
Please rely on the plugin compatibility matrix before upgrading.
There is not such an issue while upgrading from a version prior to 3.5.
The concept of Violations and Reviews has been merged into a single concept: Issues. Due to this change, some metrics have been removed, others have been added. For example, the 'Unreviewed violations' metric has been removed. If you are using it in some widgets or in alerts, you have to replace it by 'Open issues'.
Due to the migration of the concept Violations and Reviews to Issues, the migration of the database takes longer than usual.
During the database migration process, the SonarQube server might require some additional memory.
In SONARQUBE_HOME/conf/wrapper.conf, temporarily increase the value of the