Menu
Has anyone seen any analysis or info on when it is ideal to scale out vs. scale up. When does one make more sense than the other.
Currently, 2 small instances will cost the same as one medium under both the standard and basic modes.
Is having 2 small instances and thus 4 GB of RAM, the same as having 1 Medium instance with 4 GB of RAM (but without an SLA); and the same for cores. All the other features are the same.
Does either CPU pressure or memory pressure, two easy metrics, dictate which way to scale?
And, in this case, scaling out does not present an issue as far as apps/sites working on different machines.
200
Scale-up – Upgrade the capacity of the host where the app is hosted (PAAS environment). Ex: Increase the RAM size from 1 cores to 4 cores. Scale-out – Upgrade the capacity of the app by increasing the number of host instances (PAAS Environment). Ex: Having a Load Balancer where your app is hosted on multiple instances.
Scale-out allows you to combine multiple machines into a virtual single machine with the larger memory pool than a scale-up environment would need. In a scale-up you achieve higher performance over scale-out but are limited to the limitations of a single processor.
Two main ways an application can scale include vertical scaling and horizontal scaling. Vertical scaling (scaling up) increases the capacity of a resource, for example, by using a larger virtual machine (VM) size. Horizontal scaling (scaling out) adds new instances of a resource, such as VMs or database replicas.
A scale out operation is the equivalent of creating multiple copies of your web site and adding a load balancer to distribute the demand between them. When you scale out a web site in Windows Azure Web Sites there is no need to configure load balancing separately since this is already provided by the platform.
When you can, always try to scale out vs. scale up. Chances of one VM going down due to a reboot/upgrade/etc and having catastrophic downtime are much bigger than 0... while the overhead of running two VM's and load-balancing between them is minimal and chances of you having both VM's down are much much smaller.
In addition if you ever need 3 servers, scaling up with medium servers will not yield the right granularity.
125
If you love us? You can donate to us via Paypal or buy me a coffee so we can maintain and grow! Thank you!
Donate Us With
