spring-boot - 无法获取表锁 - 另一个 Flyway 实例可能正在运行

Question

我正在使用 Spring Boot 和 Flyway (6.5.5) 的集成来运行 CockroachDB 集群的更新。当多个服务实例同时启动时，所有实例都会尝试锁定flyway_schema_history表以验证迁移。但是，出现以下异常:

2020-09-09 00:00:00.013 ERROR 1 --- [           main] o.s.boot.SpringApplication               :
Application run failed org.springframework.beans.factory.BeanCreationException: 
Error creating bean with name 'flywayInitializer' defined in class path resource [org/springframework/boot/autoconfigure/flyway/FlywayAutoConfiguration$FlywayConfiguration.class]: 
Invocation of init method failed; nested exception is org.flywaydb.core.api.FlywayException: 
Unable to obtain table lock - another Flyway instance may be running

我找不到任何配置属性来调整它。也许有人遇到过同样的问题并以某种方式解决了它？

解决方法:重新启动服务。

Answer 1

调试问题后，它出现了非常奇怪的 Flyway 行为:org.flywaydb.core.internal.database.cockroachdb.CockroachDBTable

CockroachDB-specific table.
Note that CockroachDB doesn't support table locks. We therefore use a row in the schema history as a lock indicator;
if another process ahs inserted such a row we wait (potentially indefinitely) for it to be removed before
carrying out a migration.
*/

因此，就我而言，在应用迁移期间，服务被重新启动，并且该伪锁定记录永远保留。

解决方法是手动删除“锁定”:

  installed_rank |             version              |               description                | type |                      script                      |  checksum   |    installed_by    |           installed_on           | execution_time | success
-----------------+----------------------------------+------------------------------------------+------+--------------------------------------------------+-------------+--------------------+----------------------------------+----------------+----------
            -100 | d9ab17626a4d66a4d8a89fe9bdca98e9 | flyway-lock                              |      |                                                  |           0 |                    | 2020-09-14 11:25:02.874838+00:00 |              0 |  true

希望，它会对某人有所帮助。

已创建相应的票证:https://github.com/flyway/flyway/issues/2932