[Info-vax] How would you load balance excess webserver traffic between multiple OpenVMS servers?

[Bill Gunshannon]

On 1/13/21 7:40 PM, Dirk Munk wrote:
> Arne Vajhøj wrote:
>> On 1/13/2021 5:36 PM, Dirk Munk wrote:
>>> ultr... at gmail.com wrote:
>>>> On Wednesday, January 13, 2021 at 9:03:50 AM UTC-5, Dirk Munk wrote:
>>>>> D W wrote:
>>>>>> There are MULTIPLE different approaches to doing this. Most 
>>>>>> involve HTTP (web) cookies and may involve DNS round robin load 
>>>>>> balancing or load balancers.
>>>>>>
>>
>>>>> You could use a DNS server with round robin functionality. That way 
>>>>> you
>>>>> can use multiple IP interfaces on one VMS server, as well as more VMS
>>>>> servers.
>>>>>
>>
>>>> do you mean like port forwarding or a www1. type of solution? I'm 
>>>> going to implement DNS services on their system just in case for 
>>>> redundancy.
>>>
>>> No, round robin is very simple.
>>>
>>> let's say you have 4 vms ip interfaces for you server, they can be on 
>>> one server (4 interfaces) or two servers (2 x 2 interfaces) or 4 
>>> servers. The IP addresses are 10.0.0.1 , 10.0.0.2 , 10.0.0.3 , and 
>>> 10.0.0.4 , so very simple.
>>>
>>> With a round robin dns server, you will create a host www.myvms.com , 
>>> and give that host all four IP addresses.
>>>
>>> When you open a connection to www.myvms.com , it will go to 10.0.0.1 
>>> . A second later it will go to 10.0.0.2 , and again a second later to 
>>> 10.0.0.3 , and then to 10.0.0.4. , and finally back to 10.0.0.1 , and 
>>> so on.
>>
>> The key question is what happens if 10.0.0.2 is down.
>>
>> Arne
>>
> 
> Good point. A good round-robin DNS server would notice that.

Don't know much about DNS, do you?  DNS Servers have no contact
whatsoever with the machines they point at.

> 
> In fact it seems there are round-robin DNS servers that can take the 
> load of a server into account, skipping severely loaded severs for 
> instance. Don't know how that actually works.

Definitely don't now much about DNS Servers.

bill