One of 3 posts looking at the NetScaler TriScale messaging – Scale In (SDX only)
If you’re not familiar with the difference between MPX & SDX very simply MPX offers a single NetScaler in a physical appliance. SDX offers multiple NetScalers in a single physical appliance.
As organisations grow and look to support greater numbers of users, their infrastructure obviously needs to grow too. There’s a general rule of thumb that bigger environments with greater numbers of users have higher levels of service and as a result, sharing delivery mechanisms across multiple applications is no longer an option. Enterprise organisations can’t afford to let end point performance drop on application A because application B is extremely busy and taking all the delivery resource. These larger use cases require individual app delivery controllers (ADCs) for each application silo to ensure the SLAs are maintained across the infrastructure. Multiple ADCs need more rack space, power, maintenance and management to look after so the NetScaler SDX is an alternative as it offers the SLA management of the stand alone method but with the various cost savings of deploying far fewer physical appliances in the data centre.
Each NetScaler SDX physical appliance ships with a licence key that allows 5 individual NetScaler images(referred to as instances) to be run on the hardware. Each of these instances can be configured as a stand alone appliance with further packs of 5 instances available to add by licence key should more applications require delivery management. It’s possible to have up to 40 individual instances running on a single physical appliance which really starts to push the boundaries of application delivery controllers, as a result, Citrix refer to the SDX appliances as Service Delivery Controllers (SDCs)
Adding more instances in a single physical appliance – Scale In – Al
© Al Taylor 26th Sept 2012
