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

[Dirk Munk]

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.
>>>
>>> But how would this be accomplished using Apache or another web package on OpenVMS?
>>>
>>> Would you use the same approach?
>>>
>>> Also if you house a DB like RDB on a separate OpenVMS server, what would be the fastest connect solution to obtain the fastest data transport rates between the DB server and other web servers?
>>>
>>
>> First of all, I would look at WASD, and not Apache. WASD is (at least)
>> VMS Cluster aware, and is much and much more powerful (performance) than
>> Apache, at least it was the last time I looked.
>>
>> 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.
>>
>> Perhaps you can use DECRAM , however it has not been ported to x86-64
>> yet. Don't know how difficult that would be. DECRAM disks behave like
>> normal disks, so shadowing etc. is supported.
> 
> 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 DNS implementation on VMS does not support this AFAIK. Try to find a 
good round-robin DNS server, most likely on Linux, and use two very 
cheap and simple Linux servers for your DNS.