After running
composer require magento/product-community-edition 2.2.0 --no-update
composer update
I ran
bin/magento setup:upgrade
But while running this command I get the following error:
Updating modules:
Unable to unserialize value.
[InvalidArgumentException]
Unable to unserialize value.
I read that multiple developers had this problem after upgrading to Magento 2.2 and it could be a problem with installed extension, but for me there isn't any entry in the log files of Magento, PHP or MySQL.