Display cluster connections

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You can display all the active connections in the cluster or a count of active connections on the node by client, logical interface, protocol, or service. You can also display all the listening connections in the cluster.

Display active connections by client (cluster administrators only)

You can view the active connections by client to verify the node that a specific client is using and to view possible imbalances between client counts per node.

About this task

The count of active connections by client is useful in the following scenarios:

  • Finding a busy or overloaded node.

  • Determining why a particular client’s access to a volume is slow.

    You can view details about the node that the client is accessing and then compare it with the node on which the volume resides. If accessing the volume requires traversing the cluster network, clients might experience decreased performance because of the remote access to the volume on an oversubscribed remote node.

  • Verifying that all nodes are being used equally for data access.

  • Finding clients that have an unexpectedly high number of connections.

  • Verifying whether certain clients have connections to a node.

Step

Display a count of the active connections by client on a node by using the network connections active show-clients command.

For more information about this command, see the man page: ONTAP 9 commands

network connections active show-clients
Node    Vserver Name    Client IP Address     Count
------  --------------  -----------------     ------
node0   vs0             192.0.2.253                1
        vs0             192.0.2.252                2
        Cluster         192.10.2.124               5
node1   vs0             192.0.2.250                1
        vs0             192.0.2.252                3
        Cluster         192.10.2.123               4
node2   vs1             customer.example.com       1
        vs1             192.0.2.245                3
        Cluster         192.10.2.122               4
node3   vs1             customer.example.org       1
        vs1             customer.example.net       3
        Cluster         192.10.2.121               4

Display active connections by protocol (cluster administrators only)

You can display a count of the active connections by protocol (TCP or UDP) on a node to compare the usage of protocols within the cluster.

About this task

The count of active connections by protocol is useful in the following scenarios:

  • Finding the UDP clients that are losing their connection.

    If a node is near its connection limit, UDP clients are the first to be dropped.

  • Verifying that no other protocols are being used.

Step

Display a count of the active connections by protocol on a node by using the network connections active show-protocols command.

For more information about this command, see the man page.

network connections active show-protocols
Node     Vserver Name  Protocol   Count
-------  ------------  ---------  ------
node0
         vs0           UDP            19
         Cluster       TCP            11
node1
         vs0           UDP            17
         Cluster       TCP             8
node2
         vs1           UDP            14
         Cluster       TCP            10
node3
         vs1           UDP            18
         Cluster       TCP             4

Display active connections by service (cluster administrators only)

You can display a count of the active connections by service type (for example, by NFS, SMB, mount, and so on) for each node in a cluster. This is useful to compare the usage of services within the cluster, which helps to determine the primary workload of a node.

About this task

The count of active connections by service is useful in the following scenarios:

  • Verifying that all nodes are being used for the appropriate services and that the load balancing for that service is working.

  • Verifying that no other services are being used. Display a count of the active connections by service on a node by using the network connections active show-services command.

For more information about this command, see the man page: ONTAP 9 commands

network connections active show-services
Node       Vserver Name    Service    Count
---------  --------------  ---------  ------
node0
           vs0             mount           3
           vs0             nfs            14
           vs0             nlm_v4          4
           vs0             cifs_srv        3
           vs0             port_map       18
           vs0             rclopcp        27
           Cluster         ctlopcp        60
node1
           vs0             cifs_srv        3
           vs0             rclopcp        16
           Cluster         ctlopcp        60
node2
           vs1             rclopcp        13
           Cluster         ctlopcp        60
node3
           vs1             cifs_srv        1
           vs1             rclopcp        17
           Cluster         ctlopcp        60

Display active connections by LIF on a node and SVM

You can display a count of active connections for each LIF, by node and storage virtual machine (SVM), to view connection imbalances between LIFs within the cluster.

About this task

The count of active connections by LIF is useful in the following scenarios:

  • Finding an overloaded LIF by comparing the number of connections on each LIF.

  • Verifying that DNS load balancing is working for all data LIFs.

  • Comparing the number of connections to the various SVMs to find the SVMs that are used the most.

Step

Display a count of active connections for each LIF by SVM and node by using the network connections active show-lifs command.

For more information about this command, see the man page: ONTAP 9 commands

network connections active show-lifs
Node      Vserver Name  Interface Name  Count
--------  ------------  --------------- ------
node0
          vs0           datalif1             3
          Cluster       node0_clus_1         6
          Cluster       node0_clus_2         5
node1
          vs0           datalif2             3
          Cluster       node1_clus_1         3
          Cluster       node1_clus_2         5
node2
          vs1           datalif2             1
          Cluster       node2_clus_1         5
          Cluster       node2_clus_2         3
node3
          vs1           datalif1             1
          Cluster       node3_clus_1         2
          Cluster       node3_clus_2         2

Display active connections in a cluster

You can display information about the active connections in a cluster to view the LIF, port, remote host, service, storage virtual machines (SVMs), and protocol used by individual connections.

About this task

Viewing the active connections in a cluster is useful in the following scenarios:

  • Verifying that individual clients are using the correct protocol and service on the correct node.

  • If a client is having trouble accessing data using a certain combination of node, protocol, and service, you can use this command to find a similar client for configuration or packet trace comparison.

Step

Display the active connections in a cluster by using the network connections active show command.

For more information about this command, see the man page: ONTAP 9 commands

The following command shows the active connections on the node node1:

network connections active show -node node1
Vserver  Interface           Remote
Name     Name:Local Port     Host:Port           Protocol/Service
-------  ------------------  ------------------  ----------------
Node: node1
Cluster  node1_clus_1:50297  192.0.2.253:7700    TCP/ctlopcp
Cluster  node1_clus_1:13387  192.0.2.253:7700    TCP/ctlopcp
Cluster  node1_clus_1:8340   192.0.2.252:7700    TCP/ctlopcp
Cluster  node1_clus_1:42766  192.0.2.252:7700    TCP/ctlopcp
Cluster  node1_clus_1:36119  192.0.2.250:7700    TCP/ctlopcp
vs1      data1:111           host1.aa.com:10741  UDP/port-map
vs3      data2:111           host1.aa.com:10741  UDP/port-map
vs1      data1:111           host1.aa.com:12017  UDP/port-map
vs3      data2:111           host1.aa.com:12017  UDP/port-map

The following command shows the active connections on SVM vs1:

network connections active show -vserver vs1
Vserver  Interface           Remote
Name     Name:Local Port     Host:Port           Protocol/Service
-------  ------------------  ------------------  ----------------
Node: node1
vs1      data1:111           host1.aa.com:10741  UDP/port-map
vs1      data1:111           host1.aa.com:12017  UDP/port-map

Display listening connections in a cluster

You can display information about the listening connections in a cluster to view the LIFs and ports that are accepting connections for a given protocol and service.

About this task

Viewing the listening connections in a cluster is useful in the following scenarios:

  • Verifying that the desired protocol or service is listening on a LIF if client connections to that LIF fail consistently.

  • Verifying that a UDP/rclopcp listener is opened at each cluster LIF if remote data access to a volume on one node through a LIF on another node fails.

  • Verifying that a UDP/rclopcp listener is opened at each cluster LIF if SnapMirror transfers between two nodes in the same cluster fail.

  • Verifying that a TCP/ctlopcp listener is opened at each intercluster LIF if SnapMirror transfers between two nodes in different clusters fail.

Step

Display the listening connections per node by using the network connections listening show command.

network connections listening show
Vserver Name     Interface Name:Local Port        Protocol/Service
---------------- -------------------------------  ----------------
Node: node0
Cluster          node0_clus_1:7700                TCP/ctlopcp
vs1              data1:4049                       UDP/unknown
vs1              data1:111                        TCP/port-map
vs1              data1:111                        UDP/port-map
vs1              data1:4046                       TCP/sm
vs1              data1:4046                       UDP/sm
vs1              data1:4045                       TCP/nlm-v4
vs1              data1:4045                       UDP/nlm-v4
vs1              data1:2049                       TCP/nfs
vs1              data1:2049                       UDP/nfs
vs1              data1:635                        TCP/mount
vs1              data1:635                        UDP/mount
Cluster          node0_clus_2:7700                TCP/ctlopcp