ISR Computing -

Systems Analysis and Optimization Practice

At ISR Computing, we use the following approach to performance-tuning your systems:

1. Assess the problem and establish numeric values that categorize acceptable system behavior.
2. Measure the performance of the system before modification.
3. Identify the part of the system that is critical for improving the performance.
4. Modify that part of the system to remove the bottleneck.
5. Measure the performance of the system after modification.

ISR Computing uses following System Analysis and Optimization Tools:

Performance analysis - We execute performance analysis, commonly known as profiling, which is the investigation of a program's behavior using information gathered as the program runs. Its goal is to determine which sections of a program need to be optimized.

Code optimization - We enhance performance by rewriting specific portions of a program to run faster. We improve the implementation of a particular algorithm for performing a task (code tuning).

Self-tuning - Sometimes it is necessary to optimize the internal running parameters of an application in order to maximize or minimize the fulfillment of an objective function.

Load balancing - This technique is used to achieve further results from a distributed system by intelligently selecting on which machine to run an operation based on how busy all potential candidates are, and how well suited each machine is to the type of operation to be performed.

Bottleneck Identification - In any program performing a task involving a resource, there is a minimum amount of that resource needed to accomplish the task. Our goal is to identify bottleneck and suggest ways to minimize or mitigate the impact.

ISR Computing employs following WAN/Internet Optimization techniques:

Deduplication - Eliminates the transfer of redundant data across the WAN by sending references instead of the actual data. By working at the byte level, benefits are achieved across IP applications.

Compression - Relies on data patterns that can be represented more efficiently. Best suited for point to point leased lines.

Caching/Proxy - Relies on human behavior, accessing the same data over and over. Best suited for point to point leased lines, but also viable for Internet Connections and VPN tunnels. Effective use of web caching typically sees a bandwidth reduction of 15-30% on WAN links.

Protocol spoofing - Bundles multiple requests from chatty applications into one. Best suited for Point to Point WAN links.

Traffic shaping - Controls data usage based on spotting specific patterns in the data and allowing or disallowing specific traffic. Best suited for both point to point leased lines and Internet connections. May be hard to keep current with ever expanding types of applications.

Equalizing - Makes assumptions on what needs immediate priority based on the data usage. Excellent choice for wide open unregulated Internet connections and clogged VPN tunnels.

Connection Limits - Prevents access gridlock in routers and access points due to denial of service or peer to peer. Best suited for wide open Internet access links , can also be used on WAN links.

Simple Rate Limits - Prevents one user from getting more than a fixed amount of data. Best suited as a stop gap first effort for a remedying a congested Internet connection or WAN link.