Application Infrastucture Testing
A reliable high performing application delivery system is essential for the continuity of business operations and a good end user experience. When a user does experience issues accessing an application, their first inclination is to blame the network. Your primary job is to fix or exonerate the network as the root cause of poor application performance, but secondarily, assist in determining where the problem really lies – with the server or with the application. It can sometimes be challenging to pinpoint the root cause of these types of problems.
Applications rely on multiple host servers and a network of switches and routers along the path to those servers. We can provide unique analysis capability that allows you to proactively watch for network infrastructure and server issues that can lead to sluggish application performance. The Application Infrastructure analysis includes a series of performance tests run against selected devices. The test results can be trended so you can have information available that can be used to start the investigation process when a performance issue arises. The tests allow you to remotely watch the device resources and interface statistics. You can get visibility into the excessive usage of CPU, memory and disk space for target devices as well high utilization and errors on interfaces and who and what are consuming network bandwidth along a critical path.
An Overview of Each Application Infrastructure Test
A suite of ten tests are available for Application Infrastructure analysis. These tests are designed to verify and monitor the availability and performance of a network path and infrastructure devices supporting business applications and include: ICMPv4 Ping, ICMPv6 Ping, TCP Connectivity, TCP/IPv6 Connectivity, Device Resources, Path Health, Interface Monitoring, NetFlow Monitoring, DNS Lookup, and HTTP GET.
The purpose of the ICMP Ping test is to verify the network response time and whether any packet loss is occurring. This is accomplished by sending an Internet Control Message Protocol (ICMP) echo request to the IP address selected and monitoring the response. ICMP Ping supports both ICMPv4 and ICMPv6 addressing.
TCP Connectivity verifies that server and application connectivity exist. This is accomplished by opening specific TCP IPv4 and IPv6 ports on servers. The test reports the round-trip time as a combination of network latency and server connection set up time. This is done by performing the following TCP Handshake:
A TCP SYN packet is sent out on the selected port
A SYN ACK packet is sent back to the analyser
A RESET packet is sent to close the session
Device Resources test provides analysis of memory, CPU and disk utilisation and well as the monitoring of processes consuming CPU resources for servers, switches and routers. These are indicators of oversubscribed resources that impact performance by causing an application to become sluggish or stop responding altogether. If the application is performing poorly, visibility into these resource metrics for devices in the critical path to an application can assist in troubleshooting the problem; helping to isolate the problem to the network, the server or the application. This test is available for devices that support the Host Resource or enterprise MIBs. Typically enabling SNMP on a device will enable these MIBs by default.
Path Health automatically learns and displays the network route between two devices, reporting the intermediate switches and routers, and the specific interfaces a connection passes through to get to its destination application server. Optionally, these network infrastructure devices along this critical path can be incorporated into the Application Infrastructure test along with the target end device(s). This test enables a more complete view of the health of the application delivery system. By default, a ping is set up as well as NetFlow Monitoring and Interface Monitoring tests if the target can support those tests. The test configuration will indicate the capability.
Interface Monitoring analyses and troubleshoots network and application performance problems, provides visibility into servers, switches and router interface utilisation and error levels. If an interface is persistently over-utilised, or exhibiting errors, the result may be slow application response time or even loss of connectivity to the application due to introduced latency from dropped packets, buffer delay, or no response from network infrastructure devices and servers. Interface Monitoring can be configured to monitoring up to five interfaces per device for up to 24 hours.
The DNS test performs a forward or reverse DNS lookup on the default DNS server(s) (if found) and measures the response time. You may also manually enter a different DNS server too.
The HTTP GET test performs a port open request on the specified URL and measures the port open response time from the server that is serving up the web page. It also requests the specified web page and measures its response time.