Introduction
This documentation provides resolutions to situations that you may encounter while running standalone CAST Dashboards.
liquibase.exception.DatabaseException: Expected single row from
Attempting to start a CAST Dashboard may result in the following error:
Caused by: liquibase.exception.DatabaseException: Expected single row from liquibase.statement.core.SelectFromDatabaseChangeLogLockStatement@54e43bfe but got 2 at liquibase.executor.jvm.JdbcExecutor.queryForObject(JdbcExecutor.java:184) ~[liquibase-core-4.8.0.jar!/:?] at liquibase.executor.jvm.JdbcExecutor.queryForObject(JdbcExecutor.java:195) ~[liquibase-core-4.8.0.jar!/:?] at liquibase.executor.jvm.JdbcExecutor.queryForObject(JdbcExecutor.java:190) ~[liquibase-core-4.8.0.jar!/:?] at liquibase.lockservice.StandardLockService.acquireLock(StandardLockService.java:288) ~[liquibase-core-4.8.0.jar!/:?] at liquibase.lockservice.StandardLockService.waitForLock(StandardLockService.java:247) ~[liquibase-core-4.8.0.jar!/:?] at liquibase.Liquibase.lambda$update$1(Liquibase.java:214) ~[liquibase-core-4.8.0.jar!/:?]
docker restart <id|name of your container>
This error indicates that there are multiple rows in the table cast_dashboards.databasechangeloglock, where only one row is expected. The cast_dashboards schema stores data about roles, license key and users. First run the following query to check that this is indeed the case:
SELECT * FROM cast_dashboards.databasechangeloglock ORDER BY id ASC
If two or more rows are returned, now run the following query to remove all but one row:
DELETE FROM cast_dashboards.databasechangeloglock WHERE ctid NOT IN ( SELECT ctid FROM cast_dashboards.databasechangeloglock LIMIT 1 );
Finally restart the CAST Dashboard service to ensure the change is taken into account.
