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Virtual Machines & Bare Metal Servers Widget

 

The Virtual Machines & Bare Metal Servers widget provides information about the application flows on virtual machines (VMs) and bare metal servers (BMSs) in your data center. Use the widget to start flow analysis on selected active flows on a specific VM or a BMS and to view the analysis results. You can also use this widget to place a critical VM or BMS on a watchlist. Network Director will automatically initiate analysis on all flows on that VM or BMS.

Network Director uses Cloud Analytics Engine to perform flow analysis. The Compute Agent component of Cloud Analytics Engine creates a probe, or synthetic packet, that traces the path of the application flow through the network. When a device detects the probe, it collects various metrics that are sent to the Compute Agent, which then sends the metrics to the Data Learning Engine (DLE) component of the Cloud Analytics Engine. Network Director, in turn, obtains this information from DLE. For more information about Cloud Analytics Engine, see Understanding Cloud Analytics Engine and Network Director.

Flow analysis provides you with the number of hops, latency per hop, and end-to-end latency. For each hop, you can view information about the device—for example, CPU utilization, ingress and egress ports used, and traffic statistics. The information provided enables you to identify congestion points in the network that might be affecting application performance.

In addition to using the Virtual Machines & Bare Metal Servers widget, you can perform flow analysis or view the results of flow analysis by using the following widgets or tasks:

  • Recent Flow Analysis dashboard widget—This widget enables you to analyze simulated flows and to view the results of all flow analyses in the network, independent of the associated VM or BMS.

  • Device and Port Utilization dashboard widget—This widget provides a graphical view of the level of port utilization on a device. You can mouse over a representation of a port and click View active flows through this link to display the results of analysis on flows on that port.

  • View Connectivity Task in Build mode in the Datacenter view—You can view the flows on a BMS or VM and start analysis on selected flows by mousing over the BMS or VM and clicking Show active flows.

This topic describes:

Requirements for Flow Analysis

To perform flow analysis with Network Director, you must:

  • Ensure that the components of Cloud Analytics Engine are installed on your network devices and that the Compute Agent discovery file has been created and uploaded to the Data Learning Engine (DLE).

    See Understanding Cloud Analytics Engine and Network Director for more information.

  • Specify the DLE IP address under Preferences > Monitoring> Data Learning Engine Settings.

  • Enable LLDP on the servers hosting the VMs, on the BMSs, and on the connecting switches. In addition, the switches must be discovered by using the SNMP option in Network Director.

See the Cloud Analytics Engine documentation in the QFX Series switch documentation for more information about Cloud Analytics Engine.

Network Director performs flow analysis between VMs and BMSs in the following topologies:

  • BMSs connected by a Layer 3 IP fabric

  • VMs connected by VMware NSX or OpenStack VXLAN tunnels overlaid on a Layer 3 IP fabric

Virtual Machines & Bare Metal Servers Widget Main View

The main view of the Virtual Machines & Bare Metal Servers widget has two tabs that provide access to different flow analysis functions:

  • All tab—Use this tab to analyze selected flows. You can choose which flows to analyze from all active flows on a VM or BMS. You can analyze flows in either direction (source to destination or destination to source) or in both directions, and you can schedule the start and duration of the flow analysis.

  • Watchlist tab—Use this tab to analyze all flows on a VM or BMS. When you add a VM or BMS to the watchlist, Network Director starts analysis on all active flows on the device. While the device is on the watchlist, Network Director automatically starts flow analysis on any new flows that appear. To prevent the introduction of unintended overhead on devices that are not on the watchlist, flow analysis is always unidirectional—from source to destination.

Initiating Analysis on Selected Flows from the All Tab

The All tab for the Virtual Machines & Bare Metal Servers widget provides a list of VMs and BMSs known to Network Director. From this list, you can select the VMs or BMSs on which you want to perform flow analysis or for which you want to view flow analysis results.

By default, the All tab displays the 10 VMs or BMSs with the highest bandwidth utilization. To view all VMs and BMSs known to Network Director, click the expand icon at the top of the widget or View all at the bottom of the widget.

You can take the following actions:

  • Click Analyze Flows for the VM or BMS whose flows you want to analyze. Doing so displays the Analyze Flows window. If the VM or BMS does not have Cloud Analytics Engine support, the Analyze Flows link is disabled.

  • Click All Traces to view the results of previous or on-going flow analyses on the VM or BMS. For information about viewing results, see Viewing the Results of Flow Analysis.

To support flow analytics, a device must have Cloud Analytics Engine Compute Agent support. For more information, see Understanding Cloud Analytics Engine and Network Director

Note

Each Compute Agent can analyze only up to 20 flows at a time.

Table 1 describes the fields in the All tab.

Table 1: All Tab Fields

Field

Description

Default Display

Name

Name assigned to the VM or BMS.

Visible

Bandwidth Utilization (KBps)

Total bandwidth consumption in kilobytes per second.

Visible

Host

For VMs, the name of the host on which the virtual machine is running.

Hidden

IP Address

IP address of the VM or BMS.

Visible

Actions

Click Analyze Flows for the device whose flows you want to analyze. Doing so displays the Current Flows window.

Click View Results to view the results of previous or on-going flow analyses on the virtual machine.

Visible

Current Flows Window

The Current Flows window shows the active flows on the selected VM or BMS. Each flow is uniquely defined by source IP address and TCP/UDP port, destination IP address and TCP/UDP port, and transport protocol—either TCP or UDP. When a port number is commonly associated with a well-known service, the service name is also shown.

You can perform the following actions:

  • To start flow analysis immediately, select one or more flows and click Run Flow Analysis. By default, flow analysis runs for 2 hours, with a probe sent every 20 seconds.

  • To schedule the flow analysis to start at a later time or to change the flow analysis settings, click Scheduling & Advanced Settings before you click Run Flow Analysis. The Scheduling and Advanced Settings window appears, which enables you to configure the optional settings described in Table 2.

Table 2: Scheduling and Advanced Settings

Setting

Action

Schedule

Run Now—Select to start the flow analysis as soon as you click Run Flow Analysis.

Schedule Later—Select to schedule the analysis to run at a later time and enter the date and time in the fields provided. When you click Run Flow Analysis, the analysis is scheduled to run at the date and time you specified.

Scheduled flow analyses are shown only on the dashboard widgets and cannot be managed as scheduled jobs under System > Manage Jobs.

Duration

Specify how long the flow analysis runs.

Frequency

Specify how often a probe is sent on the flow path during the duration in which flow analysis is active.

Timeout

Specify how long the Compute Agent waits before timing out the flow analysis after a probe fails to respond.

Max. number of hops

Specify the maximum number of hops on which flow analysis is performed.

Select Direction

Click the arrow that indicates the direction of the flow you want to analyze: the right arrow for source to destination, the left arrow for destination to source, and the double-headed arrow for both directions.

Capture Flow Bandwidth

Select to have Network Director collect and report information about the flow bandwidth.

If you select this option, you can view the captured flow bandwidth by:

  • Displaying the traffic statistics by mousing over a device in the Flow Analysis Details window, as described in Viewing the Results of Flow Analysis.

  • Viewing active flows through a port in the Device & Port Utilization dashboard wizard.

Mirror Flows

Select to copy the packets in the flow to the IP address you specify.

Apply above settings to all other selected flows

Select to apply these settings to all flows that are currently selected.

Initiating Flow Analysis on All Flows on a VM or BMS from the Watchlist Tab

The Watchlist tab of the Virtual Machines & Bare Metal Servers widget lists all VMs or BMSs currently on the watchlist. When you place a VM or BMS on the watchlist, flow analysis traces start immediately on all flows in the VM or BMS. Each trace lasts for an hour. If the VM or BMS remains on the watchlist after the hour is up, another hour-long trace is started. During the time the VM or BMS is on the watchlist, Network Director automatically starts flow analysis on any new flows that appear. To prevent the introduction of unintended overhead on devices that are not on the watchlist, flow analysis is always unidirectional—from source to destination.

You can take the following actions on this tab:

  • Click Add to Watchlist to open the Add to Watchlist window, which lists all the VMs and BMSs you can add to the watchlist.

  • Click All Traces to open the Flow Analysis Results window and view the flow analysis results for a device.

  • Click Remove to remove a VM or BMS from the watchlist. All active traces are stopped and the VM or BMS is removed from the Watchlist tab. You can still access the flow analysis results from the All tab or from the Recent Flow Analysis widget.

    Tip

    If the Watchlist tab does not change immediately to reflect the VMs or BMSs you have added or removed from the watchlist, refresh the widget by clicking the Refresh icon on the widget title bar.

Table 3 describes the fields in the Watchlist tab.

Table 3: Watchlist Tab Fields

Field

Description

Default Display

Name

Name assigned to the VM or BMS.

Visible

Bandwidth Utilization (Kbps)

Total bandwidth consumption in kilobits per second.

Visible

Host

For VMs, the name of the host on which the virtual machine is running.

Hidden

IP Address

IP address of the VM or BMS.

Visible

Actions

Click Analyze Flows for the device whose flows you want to analyze. Doing so displays the Analyze Flows for VM window.

Click All Traces to view the results of previous or on-going flow analyses on the virtual machine.

Visible

Add to Watchlist Window

To add VMs and BMSs to the watchlist, click Add to Watchlist on the Watchlist tab. The Add to Watchlist window opens, which lists the VMs and BMSs that can be added to the watchlist.

To add VMs and BMSs to the watchlist, select one or more VMs or BMSs and click Add to Watchlist.

Note

If a VM or BMS has more than 20 active flows or if adding a VM or BMS to the watchlist would result in more than 20 flows being traced by a Compute Agent, flow analysis on the VM or BMS is not started.

Analysis on all flows starts immediately on all the VMs and BMSs you add to the watchlist. Each trace runs for an hour. After an hour, another trace automatically starts unless you remove the VM or BMS from the watchlist.

By default, a probe is sent every 20 seconds. Because all flows on the VM or BMSs are traced, you might want to reduce the frequency with which probes are sent to one every 30 seconds or longer. To change probe frequency and other settings, click Advanced Settings before you click Add to Watchlist. The available advanced settings are described in Table 4.

Table 4: Add to Watchlist Advanced Settings

Setting

Action

Frequency

Specify how often a probe is sent on the flow path during the duration in which flow analysis is active.

Timeout

Specify how long the Compute Agent waits before timing out the flow analysis after a probe fails to respond.

Max. number of hops

Specify the maximum number of hops on which flow analysis is performed.

Capture Flow Bandwidth

Select to have Network Director collect and report information about the flow bandwidth.

If you select this option, you can view the captured flow bandwidth by:

  • Displaying the traffic statistics by mousing over a device in the Flow Analysis Details window, as described in Viewing the Results of Flow Analysis.

  • Viewing active flows through a port in the Device & Port Utilization dashboard wizard.

Mirror Flows

Select to copy the packets in the flow to the IP address you specify.

Apply above settings to all other selected flows

Select to apply these settings to all VMs and BMSs that are currently selected in the Add to Watchlist window.

Viewing the Results of Flow Analysis

You can view the flow analysis results for a VM or BMS by clicking All Traces on the All tab or Watchlist tab.

You can also view flow analysis results from the Recent Flow Analysis dashboard widget.

The following sections describe:

Flow Analysis Results Window

The Flow Analysis Results window shows summary results for the flow analyses run on the VM or BMS.

Each flow analysis consists of one or more traces—a trace being a period during which flow analysis was active. Multiple traces can exist because a flow can become inactive and then active again during the duration of a flow analysis or because multiple analyses have been performed on the same flow over a period of time. By default, the Flow Analysis Results window shows the results for the most recent trace for each flow.

You can:

  • Click View Details to view in-depth analysis of the trace results.

  • Click All Traces to view the results of all traces performed on a flow.

For each flow, the information described in Table 5 is displayed.

Table 5: Flow Analysis Results Fields

Field

Description

Source IP

Source Port

Source IP address and source TCP/UDP port for the flow.

If the port is associated with a well-known service, the service name is also shown.

Destination IP

Destination Port

Destination IP address and destination TCP/UDP port for the flow.

If the port is associated with a well-known service, the service name is also shown.

Status

Status of the most recent trace analysis:

  • Active (rotating circle)—Trace has started and is ongoing.

  • Completed (check mark)—Trace completed at the end time shown.

  • Failed (red triangle)—Trace was unable to complete.

  • Scheduled (clock)—Trace is scheduled to start at the start time shown.

Start Time

End Time

Start and end time for the most recent trace analysis.

Min Latency

Lowest end-to-end latency experienced during the trace, in milliseconds.

Note: Time drift on the network devices between NTP synchronizations can result in negative values.

Max Latency

Highest end-to-end latency experienced during the trace, in milliseconds.

Avg Latency

Average end-to-end latency experienced by the trace, in milliseconds.

Action

Click View Details to open the Flow Analysis Details window, which provides in-depth path analysis for this trace.

Click All Traces to display all previously completed traces for this flow. For each trace, the information described in this table is provided.

Flow Analysis Details Window

The Flow Analysis Details window provides detailed information about a flow trace.

The Flow Analysis Details window is divided into three sections:

  • The flow path diagram—This diagram shows the path taken by a probe through the network. By default, the path shown is the path taken by the probe that experienced the highest per-hop latency in the trace. You can change this diagram to reflect the path taken by a different probe by selecting the probe from the top Latency Trend chart.

  • Latency Trend charts—These charts show the change in latency experienced by the probes during the trace. The bars in the top chart are grouped by completed probes, with each bar in a probe group representing the latency experienced by the probe at a hop. By clicking a probe group, you can change the flow path diagram and the Analysis Results section to reflect the results of that probe. For traces of long duration, the bar chart shows only a portion of the trace results.

    The bottom area chart graphs the highest latency experienced by each probe over the entire duration of the trace. You can use the provided controls to focus on a portion of the trace—the portion you choose is reflected in the top bar chart. By default, the focus is on the portion of the trace that had the highest latency. If the trace is ongoing, a rotating circle appears at the end of the plotted area and the chart is periodically refreshed to show new results.

    Both charts display a path change icon () when the path a probe takes through the network differs from the path taken by the previous probe.

  • Analysis Results—This section provides details about the overall trace results and about the selected probe:

    • The Latency table provides overall latency information for the trace: the highest and lowest latency experienced at a single hop and the average latency of all hops.

    • The Latency for Selected Path table shows the latency experienced by the selected probe at each hop.

You can perform the following actions in the Flow Analysis Details window.

General actions:

  • For bidirectional traces, you can select the direction for which you want results by clicking one of the arrows at the top of the window (these arrows do not appear for unidirectional traces).

  • To stop an active flow analysis, click Stop Flow Analysis at the bottom of the window. When you stop an active flow analysis, the results up to the time you stopped the flow analysis are retained and the previously active trace is marked as complete.

On the flow path diagram, you can:

  • Reposition the topology diagram by dragging it or reposition devices by dragging them.

  • Zoom in or out by clicking the plus or minus signs on the left.

  • Mouse over the link connecting two devices to get the connecting port names. The names are displayed in green if the link is up and in red if the link is down.

  • Mouse over a device to view details about the device, such as name, connection state, and IP address. The details shown depends on the device type.

    If a device in the flow path does not support Cloud Analytics Engine, it is shown in the diagram in light grey color and minimal details, such as IP address, are available.

  • Display the traffic statistics for switches by mousing over the device to display the device details and clicking the Show Traffic Data link. If you selected the Capture Bandwidth option when you started the flow analysis, the flow bandwidth is also displayed along with the traffic statistics.

  • Display the active flows associated with a VM, BMS, or virtualized host by mousing over the device and clicking Show Active Flows in the details box.

On the Latency Trend charts, you can:

  • Mouse over a bar group in the top bar chart. A pop-up box displays the latency figures for each hop taken by the probe.

  • Click a bar group in the top bar chart. The flow path diagram and the Analysis Results change to reflect the information for the probe.

  • Mouse over a path change icon in the top bar chart. Information about the old and new paths is displayed.

  • Change the span and position of the focus indicator on the bottom area chart:

    • To increase or decrease the time span of the focus—in other words, to zoom in or zoom out on a portion of the trace—click one of the handle controls () and move it in either direction.

    • To change the focus to another time period, click on the arrows at either end of the slider bar.