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=== Upgrade from 3.0

Planning the upgrade of an existing Apache Syncope 3.0 deployment to Syncope 4.0 can be achieved by following the
indications below.

==== Preparation

First of all, update the existing Syncope 3.0 deployment's code / Docker images to the latest
https://cwiki.apache.org/confluence/display/SYNCOPE/Maggiore[3.0 release^] available.

Also, ensure to have a full backup of the existing database used as <<persistence,internal storage>>.

==== Persistence Storage upgrade

[CAUTION]
Ensure to <<internal-storage,check the compatibility>> of the existing DBMS and upgrade, if needed.

[WARNING]
====
The existing persistence data from Syncope 3.0 can be migrated to Syncope 4.0 only if one of the 
JSON persistence flavors were in use:

* https://syncope.apache.org/docs/3.0/reference-guide.html#postgresql-jsonb[PostgreSQL JSONB^]
* https://syncope.apache.org/docs/3.0/reference-guide.html#mysql-json[MySQL JSON^]
* https://syncope.apache.org/docs/3.0/reference-guide.html#mariadb-json[MariaDB JSON^]
* https://syncope.apache.org/docs/3.0/reference-guide.html#oracle-database-json[Oracle Database JSON^]

If it is not your case, then you can apply 
https://syncope.apache.org/docs/3.0/reference-guide.html#upgrade-from-2-1[the same strategy provided^] for the migration
from Syncope 2.1 to Syncope 3.0.
====

Download https://syncope.apache.org/downloads[`syncope-core-persistence-jpa-upgrader-{docVersion}.jar`^]:
this tool will generate the full set of SQL statements required to upgrade the internal storage to Syncope 4.0.

Run the tool depending on your actual DBMS by using the latest JDK 21 available; the generated SQL statements will be
sent to a new `upgrade.sql` file.

[discrete]
===== PostgreSQL

[source,bash,subs="verbatim,attributes"]
$ java \
 -Dloader.path=/path/to/postgresql.jar
 -Ddb.jdbcURL="jdbc:postgresql://localhost:5432/syncope?stringtype=unspecified" \
 -Ddb.username=syncope -Ddb.password=syncope \
 -jar syncope-core-persistence-jpa-upgrader-{docVersion}.jar \
 upgrade.sql

assuming that:

 * `/path/to/postgresql.jar` is the full path to the latest JDBC driver available for PostgreSQL
 * you have a PostgreSQL instance running on `localhost`, listening on its default port `5432` with a database
`syncope` fully accessible by user `syncope` with password `syncope`

[discrete]
===== MySQL

[source,bash,subs="verbatim,attributes"]
$ java \
 -Dloader.path=/path/to/mysql.jar
 -Dspring.profiles.active=mysql
 -Ddb.jdbcURL="jdbc:mysql://localhost:3306/syncope?useSSL=false&allowPublicKeyRetrieval=true" \
 -Ddb.username=syncope -Ddb.password=syncope \
 -jar syncope-core-persistence-jpa-upgrader-{docVersion}.jar \
 upgrade.sql

assuming that:

 * `/path/to/mysql.jar` is the full path to the latest JDBC driver available for MySQL
 * you have a MySQL instance running on `localhost`, listening on its default port `3306` with a database
`syncope` fully accessible by user `syncope` with password `syncope`

[discrete]
===== MariaDB

[source,bash,subs="verbatim,attributes"]
$ java \
 -Dloader.path=/path/to/mariadb.jar
 -Dspring.profiles.active=mariadb
 -Ddb.jdbcURL="jdbc:mariadb://localhost:3306/syncope?characterEncoding=UTF-8" \
 -Ddb.username=syncope -Ddb.password=syncope \
 -jar syncope-core-persistence-jpa-upgrader-{docVersion}.jar \
 upgrade.sql

assuming that:

 * `/path/to/mariadb.jar` is the full path to the latest JDBC driver available for MariaDB
 * you have a MariaDB instance running on `localhost`, listening on its default port `3306` with a database
`syncope` fully accessible by user `syncope` with password `syncope`

[discrete]
===== Oracle Database

[source,bash,subs="verbatim,attributes"]
$ java \
 -Dloader.path=/path/to/ojdbc11.jar
 -Dspring.profiles.active=oracle
 -Ddb.jdbcURL="jdbc:oracle:thin:@localhost}:1521/FREEPDB1" \
 -Ddb.username=syncope -Ddb.password=syncope \
 -jar syncope-core-persistence-jpa-upgrader-{docVersion}.jar \
 upgrade.sql

assuming that:

 * `/path/to/ojdbc11.jar` is the full path to the latest JDBC driver available for Oracle Database
 * you have an Oracle instance running on `localhost`, listening on its default port `1521` with a database
`syncope` fully accessible by user `syncope` with password `syncope`

==== Finalization

. shutdown the standalone process or the Java EE container running Apache Syncope 3.0 Core, to ensure no changes
are pushed to the internal storage

. execute the SQL statements as generated above against the internal storage: in case of errors, apply manual
corrections until everything runs clear; consider to restore from the backup taken above if needed, before executing
the updated SQL statements again

. start the standalone process or the Jakarta EE container of Apache Syncope 4.0 Core, and watch the log files
to check for any error
