Database replication with host version upgrade

A method for operating a database management system, the method comprising:

• executing a first host at a first container of a cloud environment, the first host being of a first version, the first host being configured to manage a first data volume of the database management system, and the first host being configured to perform a source role for data stored at the first data volume;
• executing a second host at a second container of the cloud environment, the second host being of a second version different than the first version, the second host being configured to manage a second data volume of the database management system, and the second host being configured to perform a replica role for the source role;
• receiving, by a network layer executing at the cloud environment, a first request directed to the second host;
• determining, by the network layer, that the first request is consistent with allowed request data describing allowed requests;
• and
• sending, by the network layer, the first request to the second host at the second container.

A non-transitory machine-readable medium comprising instructions thereon that, when executed by at least one processor, cause the at least one processor to perform operations comprising:

• executing a first host at a first container of a cloud environment, the first host being of a first version, the first host being configured to manage a first data volume of a database management system, and the first host being configured to perform a source role for data stored at the first data volume;
• executing a second host at a second container of the cloud environment, the second host being of a second version different than the first version, the second host being configured to manage a second data volume of the database management system, and the second host being configured to perform a replica role for the source role;
• receiving, by a network layer executing at the cloud environment, a first request directed to the second host;
• determining, by the network layer, that the first request is consistent with allowed request data describing allowed requests;
• and
• sending, by the network layer, the first request to the second host at the second container.