Networking in .NET

Print QR Code ISO/IEC18004 in .NET Networking
Decoding QR Code 2d Barcode In VS .NET
Using Barcode Control SDK for .NET Control to generate, create, read, scan barcode image in .NET applications.
13. At the network level, realize that you want your sessions to be sticky to the back-end server on which they were created, unless that server fails. Switches that can aid in redirecting requests to maintain stickiness are essential if you re creating applications with state.
Denso QR Bar Code Creation In .NET
Using Barcode printer for .NET framework Control to generate, create QR Code image in .NET applications.
Don t rely on the source IP address of a request for a load-balancing algorithm because all traffic from a large service provider or enterprise may appear to come from a single IP address. Furthermore, some larger service providers such as America Online use a proxy that may change the source IP address of successive packets within the same session. Most switches work off of a load or availability indicator, or health check. Make sure your health check isn t intrusive to the back-end servers. If you verify the end-to-end health of your web site by invoking a URL that executes a web server plug-in to generate a large database query, each ping from the load-balancing switch is going to take a bite out of the performance of your database server. Testing the availability of back-end services should be as lightweight as possible while still yielding a reasonable up or down answer.
Scanning Denso QR Bar Code In .NET
Using Barcode scanner for VS .NET Control to read, scan read, scan image in .NET applications.
Print Barcode In .NET Framework
Using Barcode generation for .NET framework Control to generate, create barcode image in VS .NET applications.
Strolling through the backwoods has made the Verizon guy s tag line the current vernacular equivalent of Where s the beef The commercial represents a brute-force health check of a network, but the idea isn t a bad one: Find the simplest way to detect that required services are available. Load-balancing switches that are web-server savvy will invoke any URL you specify to validate that the path from switch to properly functioning web server is available. One of our larger sites generates a huge volume of dynamic content, mostly using Java Server Pages (JSPs). To ensure that the web server, application server, and all intermediate compilers and filesystems were in order, the customer chose to perform health checks using a mostly empty page with a simple JSP template in it. Unfortunately, as the JSP was executed, it created other side effects, mostly creating load on the state replication engine that slowed the application server complex down. As the frequency of the health checks increased, the volume of side effects increased as well, actually impairing the operation of the site. Building a simple JSP template without side effects solved the problem. Hal
Bar Code Scanner In Visual Studio .NET
Using Barcode reader for Visual Studio .NET Control to read, scan read, scan image in .NET framework applications.
Creating QR Code In Visual C#
Using Barcode printer for VS .NET Control to generate, create Denso QR Bar Code image in .NET framework applications.
Dynamic IP Addresses
QR Code ISO/IEC18004 Encoder In .NET Framework
Using Barcode printer for ASP.NET Control to generate, create QR Code image in ASP.NET applications.
As mentioned in the previous section, source IP addresses are not a surefire way to identify a unique client. In addition to proxy rewriting by enterprises or service providers, you ll run into the most common source of dynamic IP addresses each time you plug a PC into your corporate network: the Dynamic Host Configuration Protocol (DHCP). DHCP servers hand out IP addresses to transient devices such as PCs and laptops that enter and leave the network without any administrator effort. Users with desktop PCs may use an entire range of IP addresses over the course of a workweek; users accessing network services from home through cable modem or DSL service providers also have their IP addresses allocated dynamically. A related trend is Network Address Translation, or NAT. NAT has grown in popularity for two reasons: home networks that use NAT to allow multiple PCs to share a single connection upstream, and a dramatic reduction in the number of IPv4 addresses available. The dearth of 32-bit IP (IPv4) addresses has probably caused the increased use of NAT through home network or local network proxy devices. A NAT device manages all connections to its local devices, acting as a DHCP server for them and handing out private addresses that never are used beyond the NAT device s local network interfaces. The NAT device then talks to the outside world, mapping connections built by local PCs to the larger, outside network. Bottom line: Don t build a network service that relies on the client or source IP address to determine where the request is coming from, or where the request should be routed. You ll either need to use cookies to create a session identifier or embed session information in a URL returned by your web and application servers. We ll cover this issue in much more detail in 13.
Print Quick Response Code In Visual Basic .NET
Using Barcode drawer for VS .NET Control to generate, create QR Code JIS X 0510 image in .NET applications.
Barcode Generation In VS .NET
Using Barcode creation for Visual Studio .NET Control to generate, create barcode image in VS .NET applications.
Data Matrix Creator In .NET Framework
Using Barcode encoder for VS .NET Control to generate, create Data Matrix 2d barcode image in Visual Studio .NET applications.
Printing Code 128 Code Set A In Visual Studio .NET
Using Barcode creator for ASP.NET Control to generate, create ANSI/AIM Code 128 image in ASP.NET applications.
EAN / UCC - 13 Drawer In .NET
Using Barcode creation for ASP.NET Control to generate, create GS1-128 image in ASP.NET applications.
Make Data Matrix 2d Barcode In Java
Using Barcode generator for Java Control to generate, create Data Matrix 2d barcode image in Java applications.
Barcode Creator In Visual C#.NET
Using Barcode creation for Visual Studio .NET Control to generate, create barcode image in .NET framework applications.