Migration of H2 to mysql getting failed

Hi!!
I am trying to migrate h2 application database from docker container to mysql database (Azure flexible server).
The goal is I have already created some dashboards in metabase which is running on docker container in my local machine & I am trying to migrate the same dashboards, collections to newly deployed metabase instance on azure kubernetes service as pod (Looped to mysql database separately to store application database)

Facing the below error

Error output:
2024-01-08 07:21:08,764 INFO metabase.util :: Maximum memory available to JVM: 4.0 GB
2024-01-08 07:21:11,961 INFO util.encryption :: Saved credentials encryption is DISABLED for this Metabase instance.
For more information, see Redirecting…
2024-01-08 07:21:19,469 INFO driver.impl :: Registered abstract driver :sql
2024-01-08 07:21:19,486 INFO driver.impl :: Registered abstract driver :sql-jdbc (parents: [:sql])
2024-01-08 07:21:19,493 INFO metabase.util :: Load driver :sql-jdbc took 94.5 ms
2024-01-08 07:21:19,494 INFO driver.impl :: Registered driver :h2 (parents: [:sql-jdbc])
2024-01-08 07:21:20,059 INFO driver.impl :: Registered driver :mysql (parents: [:sql-jdbc])
2024-01-08 07:21:20,105 INFO driver.impl :: Registered driver :postgres (parents: [:sql-jdbc])
2024-01-08 07:21:22,739 INFO metabase.core ::
Metabase v0.48.1 (a8302d4)

Copyright ⌐ 2024 Metabase, Inc.

Metabase Enterprise Edition extensions are NOT PRESENT.
2024-01-08 07:21:22,963 INFO driver.impl :: Registered abstract driver :metabase.driver.sql-jdbc.execute.legacy-impl/use-legacy-classes-for-read-and-set
2024-01-08 07:21:22,969 INFO driver.impl :: Registered abstract driver :metabase.driver.sql.query-processor.empty-string-is-null/empty-string-is-null
2024-01-08 07:21:23,300 INFO cmd.copy :: Set up h2 source database and run migrations...
2024-01-08 07:21:23,302 INFO db.setup :: Verifying h2 Database Connection ...
2024-01-08 07:21:24,251 INFO db.setup :: Successfully verified H2 2.1.214 (2022-06-13) application database connection.
2024-01-08 07:21:24,252 INFO db.setup :: Running Database Migrations...
2024-01-08 07:21:24,274 INFO db.setup :: Setting up Liquibase...
2024-01-08 07:21:24,544 INFO db.setup :: Liquibase is ready.
2024-01-08 07:21:24,545 INFO db.liquibase :: Checking if Database has unrun migrations...
2024-01-08 07:21:26,194 INFO db.liquibase :: No unrun migrations found.
2024-01-08 07:21:26,201 INFO db.setup :: Database Migrations Current ...
2024-01-08 07:21:26,203 INFO metabase.util :: Database setup took 2.9 s
2024-01-08 07:21:26,301 INFO cmd.copy :: [OK]
2024-01-08 07:21:26,310 INFO cmd.copy :: Set up mysql target database and run migrations...
2024-01-08 07:21:26,319 INFO db.setup :: Verifying mysql Database Connection ...
2024-01-08 07:21:56,503 ERROR cmd.copy :: [FAIL]

clojure.lang.ExceptionInfo: ERROR Set up mysql target database and run migrations...: Unable to connect to Metabase mysql DB. {} at metabase.cmd.copy$do_step$fn__105602.invoke(copy.clj:33)
at metabase.cmd.copy$do_step.invokeStatic(copy.clj:29)
at metabase.cmd.copy$do_step.invoke(copy.clj:27)
at metabase.cmd.copy$fn__105792$copy_BANG___105797$fn__105798.invoke(copy.clj:387)
at metabase.cmd.copy$fn__105792$copy_BANG___105797.invoke(copy.clj:372)
at metabase.cmd.load_from_h2$load_from_h2_BANG_.invokeStatic(load_from_h2.clj:36)
at metabase.cmd.load_from_h2$load_from_h2_BANG_.invoke(load_from_h2.clj:26)
at clojure.lang.Var.invoke(Var.java:384)
at metabase.cmd$load_from_h2.invokeStatic(cmd.clj:74)
at metabase.cmd$load_from_h2.invoke(cmd.clj:68)
at clojure.lang.AFn.applyToHelper(AFn.java:154)
at clojure.lang.AFn.applyTo(AFn.java:144)
at clojure.core$apply.invokeStatic(core.clj:667)
at clojure.core$apply.invoke(core.clj:662)
at metabase.cmd$run_cmd$fn__106777.invoke(cmd.clj:301)
at metabase.cmd$run_cmd.invokeStatic(cmd.clj:300)
at metabase.cmd$run_cmd.invoke(cmd.clj:290)
at clojure.lang.Var.invoke(Var.java:388)
at metabase.core$run_cmd.invokeStatic(core.clj:176)
at metabase.core$run_cmd.invoke(core.clj:174)
at metabase.core$entrypoint.invokeStatic(core.clj:198)
at metabase.core$entrypoint.doInvoke(core.clj:193)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at clojure.lang.Var.applyTo(Var.java:705)
at clojure.core$apply.invokeStatic(core.clj:667)
at clojure.core$apply.invoke(core.clj:662)
at metabase.bootstrap$_main.invokeStatic(bootstrap.clj:31)
at metabase.bootstrap$_main.doInvoke(bootstrap.clj:28)
at clojure.lang.RestFn.applyTo(RestFn.java:137)
at metabase.bootstrap.main(Unknown Source)
Caused by: clojure.lang.ExceptionInfo: Unable to connect to Metabase mysql DB. {}
at metabase.db.setup$fn__50305$_AMPERSAND_f__50306$fn__50307.invoke(setup.clj:113)
at metabase.db.setup$fn__50305$AMPERSAND_f__50306.invoke(setup.clj:111)
at metabase.db.setup$fn__50305$fn__50314.invoke(setup.clj:103)
at metabase.db.setup$fn__50327$AMPERSAND_f__50328$fn__50331$fn__50332.invoke(setup.clj:142)
at metabase.util.jvm$do_with_us_locale.invokeStatic(jvm.clj:239)
at metabase.util.jvm$do_with_us_locale.invoke(jvm.clj:225)
at metabase.db.setup$fn__50327$AMPERSAND_f__50328$fn__50331.invoke(setup.clj:139)
at metabase.db.setup$fn__50327$AMPERSAND_f__50328.invoke(setup.clj:138)
at metabase.db.setup$fn__50327$fn__50339.invoke(setup.clj:132)
at metabase.cmd.copy$fn__105792$copy_BANG___105797$fn__105798$fn__105805.invoke(copy.clj:388)
at metabase.cmd.copy$do_step$fn__105602.invoke(copy.clj:30)
... 29 more
Caused by: java.sql.SQLException: Connections could not be acquired from the underlying database!
at com.mchange.v2.sql.SqlUtils.toSQLException(SqlUtils.java:118)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:692)
at com.mchange.v2.c3p0.impl.AbstractPoolBackedDataSource.getConnection(AbstractPoolBackedDataSource.java:140)
at clojure.java.jdbc$get_connection.invokeStatic(jdbc.clj:372)
at clojure.java.jdbc$get_connection.invoke(jdbc.clj:274)
at clojure.java.jdbc$db_query_with_resultset_STAR
.invokeStatic(jdbc.clj:1111)
at clojure.java.jdbc$db_query_with_resultset_STAR
.invoke(jdbc.clj:1093)
at clojure.java.jdbc$query.invokeStatic(jdbc.clj:1182)
at clojure.java.jdbc$query.invoke(jdbc.clj:1144)
at clojure.java.jdbc$query.invokeStatic(jdbc.clj:1160)
at clojure.java.jdbc$query.invoke(jdbc.clj:1144)
at metabase.driver.sql_jdbc.connection$can_connect_with_spec_QMARK
.invokeStatic(connection.clj:333)
at metabase.driver.sql_jdbc.connection$can_connect_with_spec_QMARK
.invoke(connection.clj:330)
at metabase.db.setup$fn__50305$_AMPERSAND_f__50306$fn__50307.invoke(setup.clj:111)
... 39 more
Caused by: com.mchange.v2.resourcepool.CannotAcquireResourceException: A ResourcePool could not acquire a resource from its primary factory or source.
at com.mchange.v2.resourcepool.BasicResourcePool.awaitAvailable(BasicResourcePool.java:1507)
at com.mchange.v2.resourcepool.BasicResourcePool.prelimCheckoutResource(BasicResourcePool.java:644)
at com.mchange.v2.resourcepool.BasicResourcePool.checkoutResource(BasicResourcePool.java:554)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutAndMarkConnectionInUse(C3P0PooledConnectionPool.java:758)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool.checkoutPooledConnection(C3P0PooledConnectionPool.java:685)
... 51 more
Caused by: java.sql.SQLNonTransientConnectionException: Could not connect to address=(host=$#g)(port=3306)(type=master) : Socket fail to connect to host:$#g, port:3306. $#g
at org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory.createException(ExceptionFactory.java:73)
at org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory.create(ExceptionFactory.java:197)
at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.connectWithoutProxy(AbstractConnectProtocol.java:1395)
at org.mariadb.jdbc.internal.util.Utils.retrieveProxy(Utils.java:635)
at org.mariadb.jdbc.MariaDbConnection.newConnection(MariaDbConnection.java:150)
at org.mariadb.jdbc.Driver.connect(Driver.java:89)
at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
at java.sql/java.sql.DriverManager.getConnection(Unknown Source)
at metabase.db.data_source.DataSource.getConnection(data_source.clj:31)
at com.mchange.v2.c3p0.WrapperConnectionPoolDataSource.getPooledConnection(WrapperConnectionPoolDataSource.java:161)
at com.mchange.v2.c3p0.impl.C3P0PooledConnectionPool$1PooledConnectionResourcePoolManager.acquireResource(C3P0PooledConnectionPool.java:213)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquire(BasicResourcePool.java:1176)
at com.mchange.v2.resourcepool.BasicResourcePool.doAcquireAndDecrementPendingAcquiresWithinLockOnSuccess(BasicResourcePool.java:1163)
at com.mchange.v2.resourcepool.BasicResourcePool.access$700(BasicResourcePool.java:44)
at com.mchange.v2.resourcepool.BasicResourcePool$ScatteredAcquireTask.run(BasicResourcePool.java:1908)
at com.mchange.v2.async.ThreadPoolAsynchronousRunner$PoolThread.run(ThreadPoolAsynchronousRunner.java:696)
Caused by: java.sql.SQLNonTransientConnectionException: Socket fail to connect to host:$#g, port:3306. $#g
at org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory.createException(ExceptionFactory.java:73)
at org.mariadb.jdbc.internal.util.exceptions.ExceptionFactory.create(ExceptionFactory.java:188)
at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.createSocket(AbstractConnectProtocol.java:265)
at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.createConnection(AbstractConnectProtocol.java:537)
at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.connectWithoutProxy(AbstractConnectProtocol.java:1390)
... 13 more
Caused by: java.net.UnknownHostException: $#g
at java.base/java.net.AbstractPlainSocketImpl.connect(Unknown Source)
at java.base/java.net.SocksSocketImpl.connect(Unknown Source)
at java.base/java.net.Socket.connect(Unknown Source)
at org.mariadb.jdbc.internal.protocol.AbstractConnectProtocol.createSocket(AbstractConnectProtocol.java:257)
... 15 more
Command failed with exception: ERROR Set up mysql target database and run migrations...: Unable to connect to Metabase mysql DB.

Check that error

@Luiggi
Where to check that error
"clojure.lang.ExceptionInfo: ERROR Set up mysql target database and run migrations...: Unable to connect to Metabase mysql DB"

I have no idea why that error is happening? Can you please guide out

there's simply no connection to the mysql database, either there's no route (networking), or there's a firewall blocking (networking), or MySQL won't accept the connection