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

[Dirk Munk]

Bill Gunshannon wrote:
> 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
> 


https://en.wikipedia.org/wiki/Round-robin_DNS#:~:text=Round%2Drobin%20DNS%20is%20a,according%20to%20an%20appropriate%20statistical