Ответ 1
Поставщик подключения к базе данных, когда он idd ничего не делает для повторного подключения, вам нужно указать вашему провайдеру, что делать в этом случае, например:
<persistence xmlns="http://java.sun.com/xml/ns/persistence"
xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance"
xsi:schemaLocation="http://java.sun.com/xml/ns/persistence http://java.sun.com/xml/ns/persistence/persistence_2_0.xsd"
version="2.0">
<persistence-unit name="defaultPersistenceUnit" transaction-type="RESOURCE_LOCAL">
<provider>org.hibernate.ejb.HibernatePersistence</provider>
<properties>
<property name="hibernate.dialect" value="org.hibernate.dialect.PostgreSQLDialect"/>
<property name="hibernate.show_sql" value="true"/>
<property name="hibernate.format_sql" value="true"/>
<property name="hibernate.use_sql_comments" value="true"/>
<property name="hibernate.logSql" value="true"/>
<property name="hibernate.connection.provider_class" value="com.zaxxer.hikari.hibernate.HikariConnectionProvider"/>
<property name="hibernate.hikari.dataSourceClassName" value="com.impossibl.postgres.jdbc.PGDataSource"
<property name="hibernate.hikari.timeBetweenEvictionRunsMillis="30000" />
<property name="hibernate.hikari.minEvictableIdleTimeMillis="60000"/>
<property name="hibernate.hikari.removeAbandonedOnBorrow="true" /> <property name="hibernate.hikari.removeAbandonedOnMaintenance="true" />
<property name="hibernate.hikari.maxActive="30" />
<property name="hibernate.hikari.maxIdle="10" />
<property name="hibernate.hikari.maxWait="10000" />
<property name="hibernate.hikari.initialSize="5" />
<property name="hibernate.hikari.validationQuery= "SELECT 1" />
<property name="hibernate.hikari.validationInterval="30000" />
<property name="hibernate.hikari.removeAbandoned="true" />
<property name="hibernate.hikari.removeAbandonedTimeout="60" />
<property name="hibernate.hikari.logAbandoned="true"/>
</properties>
</persistence-unit>
</persistence>
проверить эту ссылку https://github.com/brettwooldridge/HikariCP/wiki/Bad-Behavior:-Handling-Database-Down