Drill Down to the Root Cause
If network issues are affecting your application, Network Visibility can help you determine the cause:
• You see a spike in transaction outliers in the Application Dashboard. Are network issues to blame?
• Switch over to the Network Dashboard. Each tier, node, and link shows network KPIs that measure the network health of that element. Use baselining to highlight network elements with KPIs outside the baseline.
• To diagnose a tier, node, or network link, right-click and select View Metrics. In the right-click dashboard, look for network metrics with spikes that correlate with the spikes in your transaction outliers. This often provides direction to the network root cause.
• If a network element requires more in-depth troubleshooting, configure the relevant Network Agents to collect metrics on the individual Connections used by that element. You can then do the following:
• Click a node or link and view KPIs for the Connections used by the relevant nodes.
• Right-click a Connection and view detailed metrics in a right-click dashboard or in the Metric Browser.
Network Visibility Metrics
Network Visibility collects and displays these metric types:
• Network KPIs provide high-level, at-a-glance measures of whether the network is affecting the performance of the monitored application. The Network flow map shows KPIs for each tier, node, and link.
• The PIE (Performance Impacting Events) metric enables you to see immediately if there are any such events on a connected client, server, or network link.
Figure 4-28 shows an example of a PIE metric.
Figure 4-28 PIE metric
• If the KPI metrics indicate an issue with a specific element, you can view additional metrics for that element to identify root causes. Right-click an element and select View Metrics. The metrics and charts in the right-click dashboard are all designed to answer the question, are there any bottlenecks on this element that are affecting my applications?
Figure 4-29 shows an example of a KPI metric.
Figure 4-29 KPI metric
• To perform in-depth analysis, you can view detailed TCP Flow metrics in the Metric Browser.
• You can view node metrics to evaluate the health of TCP sockets and network interfaces.
Network Agents can also monitor multiple nodes that are associated with the same IP address because they run on the same physical or virtual server. The agent monitors each node individually and calculates network metrics for each node. These metrics are based on the ingress/egress traffic for each individual node, not aggregate traffic for the IP address of the host on which the node is running. Figure 4-30 illustrates an example of Network Visibility for multiple app nodes.
Figure 4-30 Network Visibility for multiple app nodes
