Ordinary database engine is deprecated but there is no simple mean to change database engine to Atomic for existing databases.

Possible options:
- ALTER DATABASE MODIFY ENGINE query.
- Flag that triggers migration at ClickHouse startup.

The latter should be easier to implement. 

const Poco::Util::AbstractConfiguration & config,
    Poco::Net::ServerSocket & socket,
    const std::string & host,
    UInt16 port,
    [[maybe_unused]] bool secure) const
{
    auto address = makeSocketAddress(host, port, &logger());
#if !defined(POCO_CLICKHOUSE_PATCH) || POCO_VERSION < 0x01090100
    if (secure)
        
        
        socket.bind(address,  true);
    else
#endif
#if POCO_VERSION < 0x01080000
    socket.bind(address,  true);
#else
    socket.bind(address,  true,  config.getBool("listen_reuse_port", false));
#endif
    
    if (port == 0)
    {
        address = socket.address();
        LOG_DEBUG(&logger(), "Requested any available port (port == 0), actual port is {:d}", address.port());
    }
    socket.listen( config.getUInt("listen_backlog", 4096));
    return address;
}
Strings getListenHosts(const Poco::Util::AbstractConfiguration & config)