Upgrade Magento2

Command Line Upgrade is always Preferable:

Step 1: Backup the existing composer.json file in the Magento installation directory.

Step 2: Remove any unnecessary packages before upgrading to Magento 2.3.2.

composer remove --dev sjparkinson/static-review fabpot/php-cs-fixer --no-update 

Step 3: Then you need to deactivate the Magento Open Source update.

composer remove magento/product-community-edition --no-update 

Step 4: Indicate to Magento 2.3.2

composer require magento/product-enterprise-edition=2.3.2 --no-update 

Step 5: Open composer.json and edit the “autoload”

"autoload": { "psr-4": { "Magento\\Framework\\": "lib/internal/Magento/Framework/", "Magento\\Setup\\": "setup/src/Magento/Setup/", "Magento\\": "app/code/Magento/", "Zend\\Mvc\\Controller\\": "setup/src/Zend/Mvc/Controller/" }, ... } 

Step 6: Modify the Magento updater

You need to modify the Magento updater if it is installed (which located in /update). First, you need to backup and remove the old updater. Then, create a Composer project.

composer create-project --repository=https://repo.magento.com magento/project-enterprise-edition=2.3.2 temp_dir --no-install 

Step 7: Check metadata in “name“, “version“, and “description” fields in the /composer.json file. If everything is okay, apply update.

composer update 

Step 8: Clear caches and generated content

rm -rf <Magento install dir>/var/cache/* rm -rf <Magento install dir>/var/page_cache/* rm -rf <Magento install dir>/generated/code/* 

Step 9: Update the database schema and data

php bin/magento setup:upgrade 

Step 10: Disable maintenance mode

php bin/magento maintenance:disable 

Step 11: Restart Varnish

service varnish restart 

Hope this will help You!!

You can upgrade your Magento application from the command line

php bin/magento maintenance:enable composer require magento/product-enterprise-edition=2.3.2 --no-update 

Specify additional packages

composer require --dev allure-framework/allure-phpunit:~1.2.0 friendsofphp/php-cs-fixer:~2.13.0 lusitanian/oauth:~0.8.10 magento/magento-coding-standard:~1.0.0 magento/magento2-functional-testing-framework:~2.3.14 pdepend/pdepend:2.5.2 phpunit/phpunit:~6.5.0 sebastian/phpcpd:~3.0.0 squizlabs/php_codesniffer:3.3.1 --sort-packages --no-update 

Remove unused packages

composer remove --dev sjparkinson/static-review fabpot/php-cs-fixer --no-update 

Update autoload

Open composer.json and edit the "autoload": "psr-4" section to include "Zend\Mvc\Controller\": "setup/src/Zend/Mvc/Controller/":

"autoload": { "psr-4": { "Magento\\Framework\\": "lib/internal/Magento/Framework/", "Magento\\Setup\\": "setup/src/Magento/Setup/", "Magento\\": "app/code/Magento/", "Zend\\Mvc\\Controller\\": "setup/src/Zend/Mvc/Controller/" }, //... } 

Remove the old update/ directory and move temp_dir/update/ to the update/ directory:

rm -rf update mv temp_dir/update . rm -rf temp_dir 

Apply updates

composer update rm -rf var/cache/ rm -rf var/page_cache/ rm -rf var/generation/ php bin/magento setup:upgrade php bin/magento maintenance:disable 

For more details: https://devdocs.magento.com/guides/v2.3/comp-mgr/cli/cli-upgrade.html