Pool metrics provide data to assess and measure performance of back end pool servers.

The Analytics information available for a pool includes Metrics related to the Pool. To access the Pool Metrics page:

  1. Navigate to Applications > Pools.

  2. Click a pool to open the Analytics tab.

  3. Click the < icon to open the Pool Metrics tile.

The Analytics tab under a pool instance presents information about various pool performance metrics. The Data shown is filtered by the period selected. Pool Metrics Tiles continuously display time-averaged data. They govern what appears in the chart display. The following metrics are available:

Metric

Description

End to End Timing

The total time from the pool’s End to End Timing graph.

Throughput

The total bandwidth passing through the virtual service in Mbps. Pointing over this graph displays the throughput in Mbps for the selected time. Throughput is measured as bytes transferred between the client and SE. It does not include data transferred between SE and the servers.

Open Conns

The number of TCP client connections or UDP transactions currently in an open state. UDP transactions are counted even though they are technically connection-less. The number of open connections does not necessarily translate into the number of unique clients, as protocols such as HTTP 1.1 typically open six connections per client browser.

If the Maximum Concurrent Connections setting has been set for a pool server, a horizontal red bar superimposed over the chart pane will show the maximum number of connections allowed.

Estimated Capacity

Estimated capacity of the pool in terms of maximum possible connections.

Available Capacity

Available capacity of the pool in terms of currently open connections.

New Connections

The number of client connections that were completed or closed over the selected period. The metric records the number of closed connections per second.

Requests

The number of HTTP requests sent to the servers assigned to the pool. This metric also shows errors sent to servers or returned by servers. Client requests that received an error response generated by the NSX Advanced Load Balancer (such as a 500 when no servers are available), are not forwarded to the pool or tracked in this view.

Servers

Displays the number of servers in the pool and their health. The x-axis represents the number of HTTP requests or connections to the server. The y-axis represents the health score of the server. The chart enables viewing of servers in relation to their peers within the pool, thus helping to spot outliers.

Within the chart pane, click and drag the mouse over server dots to select and display a table of the highlighted servers below the chart pane. The table provides more details about these servers such as Server Name, IP Address, Port, Health, Ratio (the server’s static load-balanced ratio), and Throughput. Clicking the name of a server shows the pool’s Server Insight page, which shows additional health and resource status.

CPU

The average CPU usage during the time across all servers in the pool.

Memory

The average memory usage during the period across all servers in the pool.

Pool Metrics are classified into Layer 4 and Layer 7 metrics.

Layer 4 Metrics

Metric

Description

l4_server.apdexc

Measures the network connection quality (errors and lossy connections) between Service Engines and servers.

l4_server.avg_available_capacity

Estimated connections per second capacity available for a server. This metric is the difference between the max capacity and the average load on a server.

l4_server.avg_bandwidth

Average transmit and receive network bandwidth between client and virtual service.

l4_server.avg_complete_conns

Rate of new connections per second.

l4_server.avg_connections_dropped

Rate of dropped connections per second.

l4_server.avg_errored_connections

Rate of total error connections per second.

l4_server.avg_est_capacity

Estimated averaged capacity of a server's connections per second summed across all SEs. Pool level metric reflects summed estimated capacity across all the servers in the pool.

l4_server.avg_goodput

Application data goodput (data excluding network headers) as bytes per second between the SE and server.

l4_server.avg_health_status

Health score status of the server. 0 is down.

l4_server.avg_lossy_connections

Rate of lossy connections per second between the SE and server.

l4_server.avg_new_established_conns

Rate of new established connections per second between SE and server.

l4_server.avg_open_conns

Number of concurrently open connections between SEs and servers.

l4_server.avg_pool_bandwidth

Transmit and receive network bandwidth between SEs and all servers in a pool.

l4_server.avg_pool_complete_conns

New connections per second across the virtual service or pool.

l4_server.avg_pool_errored_connections

Total connections classified as errored between Service Engines and all servers in a pool.

l4_server.avg_pool_new_established_conns

Total new connections per second established between Service Engines and all servers in a pool.

l4_server.avg_total_rtt

Average Round Trip Time across all completed (closed) connections.

l4_server.avg_uptime

Percent of time a server was marked as up.

l4_server.max_open_conns

Maximum number of concurrently open connections to a server.

l4_server.pct_connection_errors

Percent of network connections between Service Engines and a server that were dropped or lossy.

l4_server.pct_connection_saturation

Percent of a server's connection per second capacity that is estimated to be utilized.

l4_server.sum_connection_errors

Total number of network connections to a server that were dropped or were classified as lossy.

l4_server.sum_connections_dropped

Total number of network connections to a server that were dropped.

l4_server.sum_finished_conns

Total number of completed connections to a server.

l4_server.sum_health_check_failures

Total number of times a server was marked down by health monitors.

l4_server.sum_lossy_connections

Total number of network connections to a server that were classified as lossy.

l4_server.sum_lossy_req

Total number of HTTP requests that were classified as lossy due to high packet retransmissions.

Layer 7 Metrics

Metric

Description

l7_server.apdexr

Quality (combination of performance and errors) of HTTP responses from servers to the virtual service.

l7_server.avg_application_response_time

Average response latency measured of pool servers.

l7_server.avg_complete_responses

Rate of server HTTP responses per second.

l7_server.avg_error_responses

Rate of HTTP error responses sent per second. Does not include errors excluded in analytics profile.

l7_server.avg_frustrated_responses

Number of HTTP requests completed which had server response latency classified as Frustrated per the virtual service analytics profile.

l7_server.avg_resp_1xx

Rate of 1xx HTTP responses sent per second.

l7_server.avg_resp_2xx

Rate of 2xx HTTP responses sent per second.

l7_server.avg_resp_3xx

Rate of 3xx HTTP responses sent per second.

l7_server.avg_resp_4xx

Rate of 4xx HTTP responses sent per second.

l7_server.avg_resp_4xx_errors

Rate of 4xx HTTP responses per second minus error codes excluded by the analytics profile.

l7_server.avg_resp_5xx

Rate of 5xx HTTP responses sent per second.

l7_server.avg_resp_5xx_errors

Rate of 5xx HTTP responses per second minus error codes excluded by the analytics profile.

l7_server.avg_resp_latency

Latency measured for pool servers.

l7_server.avg_satisfactory_responses

Number of HTTP requests completed which had server response latency classified as Satisfied per the virtual service analytics profile.

l7_server.avg_tolerated_responses

Number of HTTP requests completed which had server response latency classified as Tolerated per the virtual service analytics profile.

l7_server.avg_total_requests

Rate of HTTP requests per second received by pool servers.

l7_server.pct_response_errors

Percent of HTTP 4xx and 5xx server responses.

l7_server.sum_get_reqs

Total number of HTTP GET requests received by servers.

l7_server.sum_other_reqs

Total number of HTTP requests that are not GET or POST request received by servers.

l7_server.sum_post_reqs

Total number of HTTP POST requests received by servers.

l7_server.sum_total_responses

Total number of HTTP responses sent from servers.

VMware Metrics

Metric

Description

vm_stats.avg_cpu_usage

Percent of server CPU used.

vm_stats.avg_cpu_wait

Percent of time virtual machine was ready to run but could not due to CPU unavailable. This could be CPU limits configured in vCenter or other virtual machines stealing CPU time.

vm_stats.avg_disk1_usage

Virtual disk1 capacity usage.

vm_stats.avg_disk2_usage

Virtual disk2 capacity usage.

vm_stats.avg_disk3_usage

Virtual disk3 capacity usage.

vm_stats.avg_disk4_usage

Virtual disk4 capacity usage.

vm_stats.avg_disk_commands_aborted

Rate of disk I/O commands that were ended prematurely in a virtual machine.

vm_stats.avg_disk_io

Rate of server disk reads plus writes per second.

vm_stats.avg_disk_read

Rate of data read from disk in kilobytes per second.

vm_stats.avg_disk_write

Rate of data written to disk in kilobytes per second.

vm_stats.avg_mem_swap_in

Total amount of data that has been read into machine memory from the swap file since the virtual machine was powered on.

vm_stats.avg_mem_swap_out

Total amount of data the VMkernel has written to the virtual machine swap file from machine memory. This statistic refers to VMkernel swapping and not to guest OS swapping.

vm_stats.avg_mem_usage

Percent of available server memory used.

vm_stats.avg_mem_vmmemctl

Virtual machine physical memory currently reclaimed from the virtual machine through ballooning. This is the amount of guest physical memory that has been allocated and pinned by the balloon driver.

vm_stats.avg_net_dropped

Rate of dropped received and transmit packets. It be an indication of network congestion.

vm_stats.avg_net_usage

Transmit plus receive network bandwidth for the virtual machine.

vm_stats.avg_port_usage

Percent of high ports used.

vm_stats.avg_uptime

Percent of time the virtual machine was up during a time interval.

vm_stats.avg_virtual_disk_commands_aborted

Number of SCSI commands that were ended prematurely.

Note:

The VMware metrics listed for Pool Metrics are also part of SE Metrics.