Figure 1-5 Scalability from the server's point of view in Java

Make Quick Response Code in Java Figure 1-5 Scalability from the server's point of view
Figure 1-5 Scalability from the server's point of view
Making QR-Code In Java
Using Barcode drawer for Java Control to generate, create QR-Code image in Java applications.
Figure 1-4 shows that our application starts to deviate from linear scalability after about 50 concurrent users With a higher number of concurrent sessions, the line migrates toward an exponential trend Notice that I'm drawing attention to the nature of the line, not the numbers to which the line corresponds As we discussed earlier, scalability analysis is not the same as performance analysis; (that is, a slow application is not necessarily unable to scale) While we are interested in the average time per request from a performance standpoint, we are more interested in performance trends with higher concurrent demand, or how well an application deals with increased load, when it comes to scalability Figure 1-5 shows that a theoretical application should maintain a constant number of transactions per second This makes sense: Even though our average response time may increase, the amount of work done per unit time remains the same (Think of a kitchen faucet: It is reasonable that even though it takes longer to wash 100 dishes than to wash one, the number of dishes per second should remain constant) Notice that our mythical application becomes less productive after 50 concurrent users In this sense, it would be better to replicate our application and limit the number of concurrent users to 50 if we want to achieve maximum throughput
Generating Barcode In Java
Using Barcode creator for Java Control to generate, create bar code image in Java applications.
Table 1-4 Linearly Scalable Application Response and Throughput Times Concurrent Users 1 50 100 150 200 Average Response Time (ms) 10 500 1000 1500 2000 Throughput (tps) 100 100 100 100 100
Bar Code Recognizer In Java
Using Barcode decoder for Java Control to read, scan read, scan image in Java applications.
Analyzing response time and throughput trends, as we have done here, is important for gauging the scalability of your system Figures 1-4 and 1-5 show how to compare an application and its theoretical potential Figure 1-4 illustrates the efficiency from the client's point of view, where the focus is on latency; Figure 1-5 shows application efficiency from the server's point of view, where the focus is on productivity (work done per time unit)
QR Code Drawer In C#
Using Barcode creator for .NET Control to generate, create QR-Code image in .NET applications.
Throughput and Price/Performance
Make QR Code JIS X 0510 In .NET
Using Barcode creator for ASP.NET Control to generate, create QR Code ISO/IEC18004 image in ASP.NET applications.
In measuring throughput, we have ignored the cost of the systems we are analyzing If a system costing $100 can handle 1,000 transactions per second and a system costing $500,000 can handle 1,200 transactions per second, the latter obviously has better throughput but it's gained at a much higher cost The idea of measuring throughput and its relationship to price is something that has been popularized by the Transaction Processing Council (TPC), which has created database benchmarks, better known as the TPC-style benchmarks There are three TPC benchmarks: TPC-A, TPC-B, and TPC-C The most recently developed (as of this writing) is the TPC-C It measures database transaction processing in terms of how efficiently it supports a mythical ordering system Specifically, it measures how many "new order" transactions can be handled while the system is busy handling four other types of order-related transactions (payment, status, etc) While the TPC specification is meant to measure database throughput, you can use the same principle with your systems After all, Web application transactions are at their core a set of database transactions Although it is unlikely that you will benchmark your system against another, you can measure how well your system is improving or lagging over its own evolution For example, if release 1 of your application requires $100,000 worth of hardware and software and nets 10,000 transaction per second, you can calculate a price/performance index by dividing the price by the performance:
QR Code Creator In .NET
Using Barcode encoder for .NET framework Control to generate, create QR Code 2d barcode image in VS .NET applications.
This doesn't mean that it costs $10 to execute a transaction on your system It is simply a measure of throughput as it relates to the overall cost of the system Suppose that a year later, release 2 of your application requires $150,000 worth of hardware and handles 40,000 transactions per second The release 2 price/performance index would be:
Making Quick Response Code In Visual Basic .NET
Using Barcode maker for .NET framework Control to generate, create Denso QR Bar Code image in .NET framework applications.
Obviously, release 2 is more efficient than release 1 by evidence of its lower price/ performance figure My interest in price/performance in this section is a reminder of the more general bias throughout this book: Favor architectural strategies over resources when developing your application Once the application is deployed, you can always buy more resources to meet demand On the other hand, rewriting code, changing designs, or re-architecting your application after deployment comes at a much higher cost The best solution is obviously good design at the outset for scalability and performance Not only does this eliminate the need for massive design changes after deployment, but it also typically leads to more cost-efficient resource acquisitions CPUs, memory, disk, and other resources are purchased less frequently for applications that are inherently fast and scalable In short, well-designed systems adapt and evolve much better than poorly designed ones do
Paint Barcode In Java
Using Barcode generation for Java Control to generate, create bar code image in Java applications.
Encoding Code-128 In Java
Using Barcode encoder for Java Control to generate, create Code 128 Code Set B image in Java applications.
Creating EAN 13 In Java
Using Barcode drawer for Java Control to generate, create EAN / UCC - 13 image in Java applications.
MSI Plessey Printer In Java
Using Barcode generation for Java Control to generate, create MSI Plessey image in Java applications.
Universal Product Code Version A Decoder In .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in .NET framework applications.
Making ANSI/AIM Code 39 In VS .NET
Using Barcode maker for .NET framework Control to generate, create Code 39 Extended image in .NET applications.
ECC200 Maker In .NET Framework
Using Barcode generator for VS .NET Control to generate, create Data Matrix image in Visual Studio .NET applications.