[Info-vax] Marketing ideas for VSI ?

[Arne Vajhøj]

On 12/15/2018 1:37 PM, Dave Froble wrote:
> On 12/15/2018 10:33 AM, Kerry Main wrote:
>> Actually network latency is primarily based on speed of light (hops 
>> also),
>> and this has not changed since the speed of light was originally 
>> calculated.
>>
>> Other factors to consider for long distance clusters and how far apart 
>> the
>> can be is the R/W ration of the application This is because active-active
>> clusters with load balancing across both sites requires  synch 
>> replication.
>> A heavy write app will mean you will likely need to have sites closer
>> together than the standard 100km rule of thumb that is usually stated 
>> in the
>> context of long distance clusters. This causes performance issues if a 
>> heavy
>> write bogs down the app while it is waiting for writes to occur at both
>> sites before the update is considered complete at either site.
> 
> For most problems, there can be solutions, if the problem is properly 
> analyzed, and one is open to all possible solutions.
> 
> CPUs have been hitting this wall for a while now, either in true speed, 
> or, in the amount of heat they can tolerate.  One of the solutions there 
> is more CPUs, and even switching between them, based upon heat.
> 
> Now, I'm not a network person.  I'm lucky if I can properly plug in an 
> RJ45 plug.  But, I'd ask, if you have more to push through a pipe than 
> the pipe can handle, why not more pipes?
> 
> Someone is going to solve this problem.  Might be nice if it was first 
> implemented on VMS clusters.

Bandwidth is a problem that can be done something about.

Latency has a very hard limit in the law of physics.

Both light in fiber and electro-magenetic pulse (not the same
as the actual electron movement) in metal moves at the
speed of light.

186000 miles per second may sound like a lot, but it is only 186 miles
per millisecond.

So it is impossible to get a request from NY to LA and response
back in less than 30 milliseconds.

No matter what progress you make in network technology.

(ignoring the wormhole option)

Arne