Software VS Hardware Load balancer?

Question

Load balancing

Task: It is necessary to make a failover Load Balancer (LB) for web servers.
Options:
1. Software:
HAProxy on two nodes + keepalived. The issue of DNS remains unclear: if you use A-record for the Master node, then if the master physically falls, the slave will not be able to take its place in any way - there is no entry in the DNS. If you create two A-records, then when one server crashes, half of the requests will try to reach the fallen server, because at the DNS level, RoundRobin is used.
2. Hardware:
Rent a piece of hardware from the data center. Minus - you have to pay for the traffic passing through the balancer.
3. Advanced Software:
Use two A-records + monitoring server. When alerted, the monitoring server through the API removes the entry for the fallen LB. Minus - the IP address remains in the user cache for some time.
Actually the question is:
who and how balances the load with redundancy for web servers?
Thanks in advance for your replies.

Answer 1

Discard the variant with dns completely due to the general caching of dns requests from providers.
If you are just asking the price, then I recommend starting with a cloud balancer from rackspace or amazon

Answer 2

A piece of iron is the best option, although it depends on what, really. Decent ones, such as citrix netscaler, brocade, radware, efpyat, cisco and crescendos have normal clustering of the balancers themselves, the fall of one piece of iron is imperceptible to the naked eye. I don't know about your ISP.
Soft with crutches in dns and api is a spare, economy option. You can achieve a two-minute downtime by setting the minimum TTL=60 seconds in the DNS. But if the audience is very large (millions of users), then caching glitches will begin to appear in some applications and operating systems that do not comply with RFC1034.