ScaleArc sizing

Last modified Dec, 04, 2017

ScaleArc sizing

ScaleArc calculates the size of the appliance according to the number of active cores on the database servers serving your application traffic volume. ScaleArc Support generates a customer license, based on these sizing requirements.

In the following section, we’ll look at each of the components required in a ScaleArc appliance and how to size them properly. Follow these steps:

Step 1: Determine the size for of ScaleArc

We determine the number of cores required in a ScaleArc appliance by examining the number of cores in the database servers that the ScaleArc appliance will serve. Review the following table:

100 % active database cores under management	Up to 32	Up to 64	Up to 80	Up to 96	Up to 128	Up to 160	Up to 192
ScaleArc Size	4 cores	8 cores	10 cores	12 cores	16 cores	20 cores	24 cores

Make sure to calculate as follows:

Count the cores in the database servers that process the live READ or WRITE database traffic.
Do not count passive nodes, inactive slaves, or idle backup replicas.
Determine what percentage of activity those cores consume at peak.

If you intentionally overprovision your database servers, include the overprovisioned cores at the desired level of activity in your count.

To calculate the number of cores required for the ScaleArc appliance, divide the number of cores by 8, and then multiply the result by the percentage of activity in those cores at peak.

ScaleArc requires a minimum of four cores in each appliance. In case your calculation requires fewer than four cores, ScaleArc recommends you round up the calculated size of a ScaleArc license to four. Similarly, if the calculated size of a ScaleArc license comes out to an odd number, it must be rounded up to the next even number.

This value represents the size of the ScaleArc license.

Example

If you have two active database servers, each with 48 cores, and their peak level of activity is 75%, that’s 96 cores, divided by 8, which is 12. 12 times 75% is 9, and since we round up to even numbers, you would need a 10-core ScaleArc license.

Step 2: Determine the number of processor cores

The ScaleArc appliance needs additional CPU resources for the operating system and other overheads. The table in this section gives an overview of the processor core requirements in a ScaleArc appliance, depending largely on the CPU architectures in use.

ScaleArc license size	4 cores	8 cores	10 cores	12 cores	16 cores	20 cores	24 cores
Intel Xeon Physical Cores (no Hyperthreading)	6	12	12	16	20	24	32
Hyperthreaded Intel Xeon Physical Cores	12	24	24	32	40	48	64
Other Cores (AMD, VM, Public Cloud)	10	16	24	24	32	40	46

The amount of overhead required depends on the underlying CPU architecture and the size of the ScaleArc license. For instance:

If you are using Intel Xeon physical CPUs, add one core and then add an additional core for each of the four cores in the ScaleArc license. If the result is an odd number, round up to the next even number. If you have enabled hyperthreading in your Xeon, double the number of cores.
If you are using an AMD CPU or you’re running on a virtual machine, or are in the cloud, then your ScaleArc license gives you access to 50% more cores. In this instance, add one core and an additional core, plus one more core for every four cores in the ScaleArc license, add 50%, and round up to the next even number. You’ll use these cores for ScaleArc, without increasing the size of your license; our Fair Licensing model ensures that everyone gets the performance and capacity that they pay for.

Note that the number of ScaleArc cores may not exceed 85% of the cores in the entire ScaleArc appliance.

Step 3: Determine the memory requirements

Use the following table to calculate the recommended memory requirements for running ScaleArc:

ScaleArc license size	4 cores	8 cores	10 cores	12 cores	16 cores	20 cores	24 cores
Memory (ScaleArc Platinum Edition)	24 GB	40 GB	48 GB	54 GB	80 GB	96 GB	96 GB

Tip

ScaleArc requires a minimum of 16 GB for installation and upgrade. Contact support@scalearc.com for further details.

The ScaleArc operating system and system overhead memory require at least an additional 4 GB.

Step 4: Calculate the disk space

Use the following table to determine the disk space requirements:

ScaleArc license size	4 cores	8 cores	10 cores	12 cores	16 cores	20 cores	24 cores
Disk	2 TB	4 TB	8 TB	8 TB	8 TB	8 TB	8 TB

Of the total disk space, ScaleArc uses 50GB for the OS and the remaining space for logging storage. ScaleArc requires a minimum of 500 GB of log space per core, which can be thin-provisioned. The size of the swap is always twice the size of the RAM assigned to ScaleArc.

Logging storage requires an approximately estimated 1 GB of storage for every two million queries stored. If needed, add more disk capacity to retain more historical data or increase the number of retained transactions. Production environments typically run with 1 TB or more of disk space to retain one to three months of historical data. If the ScaleArc appliance runs low on logging disk space, a ScaleArc service erases the oldest logs first.

In general, ScaleArc recommends 2 TB of disk space on a 4-core ScaleArc license and 8 TB for more. Ensure each physical disk is not more than 2TB in size. ScaleArc recommends using solid state disks because of the increased performance.

Step 5: Determine network requirements

ScaleArc recommends using a pair of bonded or trunked network interfaces on the appliance.

ScaleArc license size	4 cores	8 cores	10 cores	12 cores	16 cores	20 cores	24 cores
Network	Two Bonded 1 GbE	Two Bonded 1 GbE	Two Bonded 1 GbE	Two Bonded 1 GbE	Two Bonded 10 GbE	Two Bonded 10 GbE	Two Bonded 10 GbE

Tip

For a ScaleArc license of 12 cores or fewer the bonded Ethernet devices can be 1 gigabit/second.
For a ScaleArc license larger than 12 cores, the bonded devices should be 10 gigabits/second.

Step 6: Determine High Availability and redundancy

A single ScaleArc appliance can create a single point of failure. As a result, ScaleArc strongly recommends using two appliances in a redundant failover configuration for production implementations. Both appliances must be built with identical configurations in terms of the number of CPUs, memory, and disk space.

Step 7: Determine the environment for ScaleArc

ScaleArc software can run on Bare Metal, a virtual machine (HyperV, VMware, KVM, or Xen), or in the cloud. ScaleArc is supported on Amazon Web Services (AWS), Microsoft Azure, VMware Air, and many other leading cloud providers.

On-premise ScaleArc system requirements

100 % active database cores under management	Up to 32	Up to 64	Up to 80	Up to 96	Up to 128
ScaleArc size	4 cores	8 cores	10 cores	12 cores	16 cores
Intel Xeon Physical Cores (no Hyperthreading)	6	12	12	16	20
Hyperthreaded Intel Xeon Physical Cores	12	24	24	32	40
Other Cores (AMD, VM, Public Cloud)	10	16	24	24	32
Memory (ScaleArc Enterprise Edition)	16 GB	16 GB	20 GB	24 GB	32 GB
Memory (ScaleArc Platinum Edition)	24 GB	40 GB	48 GB	54 GB	80 GB
Disk	2 TB	4 TB	8 TB	8 TB	8 TB
Network	Two Bonded 1 GBE	Two Bonded 1 GBE	Two Bonded 1 GBE	Two Bonded 1 GBE	Two Bonded 10 GBE

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