Hello all,
I am having some issues with upgrading my confluence server as previously stated. I am changing distributions as well although I don't think that this would cause an issue. One notable difference that I have this go around is that I am using a highly available MySQL 5.6 3 node cluster via Galera.

Hera is the corresponding log events for this:
2018-04-11 05:38:17,805 ERROR [Long running task: Importing data] [engine.jdbc.spi.SqlExceptionHelper] logExceptions No operations allowed after connection closed.
-- url: /setup/longrunningtaskxml.action | traceId: 6a5a74143e20b185 | userName: anonymous | referer: http://grimoire.scriptmyjob.com/setup/setup-restore-progress.action?taskId=913b9549-4451-4f67-bc54-7f259ff156c9 | action: longrunningtaskxml
2018-04-11 05:38:17,829 WARN [Long running task: Importing data] [confluence.upgrade.impl.DefaultUpgradeManager] setDatabaseBuildNumber Unable to set build number '7502' in the database
-- url: /setup/longrunningtaskxml.action | traceId: 6a5a74143e20b185 | userName: anonymous | referer: http://grimoire.scriptmyjob.com/setup/setup-restore-progress.action?taskId=913b9549-4451-4f67-bc54-7f259ff156c9 | action: longrunningtaskxml
org.springframework.dao.DataAccessResourceFailureException: could not prepare statement; nested exception is org.hibernate.exception.JDBCConnectionException: could not prepare statement
at org.springframework.orm.hibernate5.SessionFactoryUtils.convertHibernateAccessException(SessionFactoryUtils.java:220)
at org.springframework.orm.hibernate5.HibernateTemplate.doExecute(HibernateTemplate.java:366)
at org.springframework.orm.hibernate5.HibernateTemplate.executeWithNativeSession(HibernateTemplate.java:326)
at org.springframework.orm.hibernate5.HibernateTemplate.findByNamedQueryAndNamedParam(HibernateTemplate.java:989)
at org.springframework.orm.hibernate5.HibernateTemplate.findByNamedQueryAndNamedParam(HibernateTemplate.java:978)
at com.atlassian.confluence.core.persistence.hibernate.HibernateVersionHistoryDao.getVersionHistory(HibernateVersionHistoryDao.java:44)
at com.atlassian.confluence.core.persistence.hibernate.HibernateVersionHistoryDao.addBuildToHistory(HibernateVersionHistoryDao.java:116)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at com.atlassian.spring.interceptors.SpringProfilingInterceptor.invoke(SpringProfilingInterceptor.java:16)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy161.addBuildToHistory(Unknown Source)
at com.atlassian.confluence.upgrade.impl.DefaultUpgradeManager.setDatabaseBuildNumber(DefaultUpgradeManager.java:200)
at com.atlassian.confluence.upgrade.impl.DefaultUpgradeManager.setDatabaseBuildNumber(DefaultUpgradeManager.java:187)
at com.atlassian.confluence.importexport.xmlimport.BackupImporter.doUpgrades(BackupImporter.java:354)
at com.atlassian.confluence.importexport.xmlimport.BackupImporter.doImportInternal(BackupImporter.java:229)
at com.atlassian.confluence.importexport.Importer.doImport(Importer.java:73)
at com.atlassian.confluence.importexport.DefaultImportExportManager.performImportInternal(DefaultImportExportManager.java:131)
at com.atlassian.confluence.importexport.DefaultImportExportManager.doPerformImport(DefaultImportExportManager.java:119)
at com.atlassian.confluence.importexport.DefaultImportExportManager.performImport(DefaultImportExportManager.java:114)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy243.performImport(Unknown Source)
at com.atlassian.confluence.importexport.actions.ImportLongRunningTask.runInternal(ImportLongRunningTask.java:74)
at com.atlassian.confluence.util.longrunning.ConfluenceAbstractLongRunningTask.run(ConfluenceAbstractLongRunningTask.java:26)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at com.atlassian.confluence.tenant.TenantGate$3.call(TenantGate.java:145)
at com.atlassian.confluence.tenant.OpenTenantGateLongRunningTask.run(OpenTenantGateLongRunningTask.java:24)
at com.atlassian.confluence.util.longrunning.ManagedTask.run(ManagedTask.java:52)
at com.atlassian.confluence.impl.util.concurrent.ConfluenceExecutors$ThreadLocalContextTaskWrapper.lambda$wrap$1(ConfluenceExecutors.java:90)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.lambda$doInRequestContext$0(VCacheRequestContextOperations.java:50)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContextInternal(VCacheRequestContextManager.java:87)
at com.atlassian.confluence.impl.vcache.VCacheRequestContextManager.doInRequestContext(VCacheRequestContextManager.java:71)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.doInRequestContext(VCacheRequestContextOperations.java:49)
at com.atlassian.confluence.vcache.VCacheRequestContextOperations.lambda$withRequestContext$2(VCacheRequestContextOperations.java:66)
at java.util.concurrent.Executors$RunnableAdapter.call(Executors.java:511)
at java.util.concurrent.FutureTask.run(FutureTask.java:266)
at java.util.concurrent.ThreadPoolExecutor.runWorker(ThreadPoolExecutor.java:1149)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:624)
at java.lang.Thread.run(Thread.java:748)
Caused by: org.hibernate.exception.JDBCConnectionException: could not prepare statement
at org.hibernate.exception.internal.SQLExceptionTypeDelegate.convert(SQLExceptionTypeDelegate.java:48)
at org.hibernate.exception.internal.StandardSQLExceptionConverter.convert(StandardSQLExceptionConverter.java:42)
at org.hibernate.engine.jdbc.spi.SqlExceptionHelper.convert(SqlExceptionHelper.java:111)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:182)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl.prepareQueryStatement(StatementPreparerImpl.java:148)
at org.hibernate.loader.Loader.prepareQueryStatement(Loader.java:1940)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1909)
at org.hibernate.loader.Loader.executeQueryStatement(Loader.java:1887)
at org.hibernate.loader.Loader.doQuery(Loader.java:932)
at org.hibernate.loader.Loader.doQueryAndInitializeNonLazyCollections(Loader.java:349)
at org.hibernate.loader.Loader.doList(Loader.java:2615)
at org.hibernate.loader.Loader.doList(Loader.java:2598)
at org.hibernate.loader.Loader.listIgnoreQueryCache(Loader.java:2430)
at org.hibernate.loader.Loader.list(Loader.java:2425)
at org.hibernate.loader.hql.QueryLoader.list(QueryLoader.java:502)
at org.hibernate.hql.internal.ast.QueryTranslatorImpl.list(QueryTranslatorImpl.java:370)
at org.hibernate.engine.query.spi.HQLQueryPlan.performList(HQLQueryPlan.java:216)
at org.hibernate.internal.SessionImpl.list(SessionImpl.java:1481)
at org.hibernate.query.internal.AbstractProducedQuery.doList(AbstractProducedQuery.java:1441)
at org.hibernate.query.internal.AbstractProducedQuery.list(AbstractProducedQuery.java:1410)
at org.springframework.orm.hibernate5.HibernateTemplate$33.doInHibernate(HibernateTemplate.java:1001)
at org.springframework.orm.hibernate5.HibernateTemplate$33.doInHibernate(HibernateTemplate.java:989)
at org.springframework.orm.hibernate5.HibernateTemplate.doExecute(HibernateTemplate.java:359)
... 58 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: No operations allowed after connection closed.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.Util.getInstance(Util.java:408)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:919)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:898)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:887)
at com.mysql.jdbc.SQLError.createSQLException(SQLError.java:861)
at com.mysql.jdbc.ConnectionImpl.throwConnectionClosedException(ConnectionImpl.java:1184)
at com.mysql.jdbc.ConnectionImpl.checkClosed(ConnectionImpl.java:1179)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4071)
at com.mysql.jdbc.ConnectionImpl.prepareStatement(ConnectionImpl.java:4040)
at com.mchange.v2.c3p0.impl.NewProxyConnection.prepareStatement(NewProxyConnection.java:387)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$5.doPrepare(StatementPreparerImpl.java:146)
at org.hibernate.engine.jdbc.internal.StatementPreparerImpl$StatementPreparationTemplate.prepareStatement(StatementPreparerImpl.java:172)
... 77 more
Caused by: com.mysql.jdbc.exceptions.jdbc4.CommunicationsException: Communications link failure
The last packet successfully received from the server was 145,197 milliseconds ago. The last packet sent successfully to the server was 0 milliseconds ago.
at sun.reflect.NativeConstructorAccessorImpl.newInstance0(Native Method)
at sun.reflect.NativeConstructorAccessorImpl.newInstance(NativeConstructorAccessorImpl.java:62)
at sun.reflect.DelegatingConstructorAccessorImpl.newInstance(DelegatingConstructorAccessorImpl.java:45)
at java.lang.reflect.Constructor.newInstance(Constructor.java:423)
at com.mysql.jdbc.Util.handleNewInstance(Util.java:425)
at com.mysql.jdbc.SQLError.createCommunicationsException(SQLError.java:990)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3559)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3459)
at com.mysql.jdbc.MysqlIO.checkErrorPacket(MysqlIO.java:3900)
at com.mysql.jdbc.MysqlIO.sendCommand(MysqlIO.java:2527)
at com.mysql.jdbc.MysqlIO.sqlQueryDirect(MysqlIO.java:2680)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2480)
at com.mysql.jdbc.ConnectionImpl.execSQL(ConnectionImpl.java:2438)
at com.mysql.jdbc.StatementImpl.executeQuery(StatementImpl.java:1381)
at com.mchange.v2.c3p0.impl.NewProxyStatement.executeQuery(NewProxyStatement.java:327)
at com.atlassian.confluence.core.persistence.hibernate.HibernateVersionHistoryDao.getLatestBuildNumber(HibernateVersionHistoryDao.java:30)
at sun.reflect.NativeMethodAccessorImpl.invoke0(Native Method)
at sun.reflect.NativeMethodAccessorImpl.invoke(NativeMethodAccessorImpl.java:62)
at sun.reflect.DelegatingMethodAccessorImpl.invoke(DelegatingMethodAccessorImpl.java:43)
at java.lang.reflect.Method.invoke(Method.java:498)
at org.springframework.aop.support.AopUtils.invokeJoinpointUsingReflection(AopUtils.java:302)
at org.springframework.aop.framework.ReflectiveMethodInvocation.invokeJoinpoint(ReflectiveMethodInvocation.java:190)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:157)
at com.atlassian.spring.interceptors.SpringProfilingInterceptor.invoke(SpringProfilingInterceptor.java:16)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.transaction.interceptor.TransactionInterceptor$1.proceedWithInvocation(TransactionInterceptor.java:99)
at org.springframework.transaction.interceptor.TransactionAspectSupport.invokeWithinTransaction(TransactionAspectSupport.java:281)
at org.springframework.transaction.interceptor.TransactionInterceptor.invoke(TransactionInterceptor.java:96)
at org.springframework.aop.framework.ReflectiveMethodInvocation.proceed(ReflectiveMethodInvocation.java:179)
at org.springframework.aop.framework.JdkDynamicAopProxy.invoke(JdkDynamicAopProxy.java:208)
at com.sun.proxy.$Proxy161.getLatestBuildNumber(Unknown Source)
at com.atlassian.confluence.upgrade.impl.DefaultUpgradeManager.setDatabaseBuildNumber(DefaultUpgradeManager.java:197)
... 37 more
Caused by: java.io.EOFException: Can not read response from server. Expected to read 4 bytes, read 0 bytes before connection was unexpectedly lost.
at com.mysql.jdbc.MysqlIO.readFully(MysqlIO.java:3011)
at com.mysql.jdbc.MysqlIO.reuseAndReadPacket(MysqlIO.java:3469)
... 62 more
Here is my Infrastructure as code for standing up the Galera Cluster:
https://github.com/ScriptMyJob/Galera_Cluster
And here is my IaC for the Confluence App server:
https://github.com/ScriptMyJob/Grimoire
Any help would be very much appreciated.
Repsectfully,
Robert J.