Not enough gigabit channel per server?

Question

Highload

There is a caching server (Varnish): upon request, it takes data from Amazon S3, remembers it for a while and gives it to the client. Faced with the problem that there is not enough bandwidth of the channel in 1GBit. Peak load within 4 hours completely clogs the channel. Server performance is still enough. Approximately 4.5TB of data is given per day. More than 100TB accumulates in a month.
The first thought is to simply add another gigabit port and sleep peacefully until 2GBit is not enough (and this can happen very quickly), or when one server can no longer cope.
And then you should already add new caching servers, but now you need a balancer that will also send a request to the same URL always to the same server (so that copies of the same cached objects do not multiply).
Now questions:

1. After all, the balancer will now need a bandwidth equal to the sum of all the bandwidths of the caching servers. How then to be when you simply no longer plug new ports into the balancer? Add more balancers and resolve via Round robin DNS?
   
2. What standard approaches exist for solving such problems?
   
3. Can anyone recommend a hosting company that can help solve this problem? Interested in the American and European market
   

Answer 1

and what, LACP channel aggregation cannot be ordered from the provider?

Answer 2

The balancer may not drive all the traffic through itself, but redirect the request to one of the caching servers through a redirect.

Answer 3

Can't share content across multiple servers?

Answer 4

Check out LVS. IP Tunneling and Direct Routing variants, judging by the description of www.linuxvirtualserver.org/how.html, solve the problem with the narrow channel of the balancer, giving a response through their channels.
Unfortunately, I haven't come across it in practice yet.

Answer 5

if an honest balancer
, then you can install ADX 1016
and you can sleep peacefully
www.brocade.com/products/all/application-delivery-controllers/product-details/serveriron-adx-series/index.page

Answer 6

Have optical 10G ports been cancelled?

Answer 7

traffic, as I understand it, consists of statics?