Asadm shows a mix of fqdn and ip addresses under the Node column


#1

FAQ why asadm showing a mix of fqdn and ip addresses under the Node column

Detail

The output of asadm is inconsistent showing a mix of ip addresses and Fully Qualified Domain Name (FQDN) under the Node column: e.g.

asadm -h 192.168.120.215 -e info                                                                                                                                          ⏎
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Network Information~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cluster                            Node               Node                     Ip        Build   Cluster            Cluster     Cluster         Principal   Client      Uptime   
   Name                               .                 Id                      .            .      Size                Key   Integrity                 .    Conns           .   
v24dc1    192.168.120.188:3000            BB9AC3883005452    192.168.120.188:3000   E-3.11.1.1         4   1AB3C17DED7E91E8   True        BB9DB3754005452        7   04:37:41    
v24dc1    192.168.120.216:3000            *BB9DB3754005452   192.168.120.216:3000   E-3.11.1.1         4   1AB3C17DED7E91E8   True        BB9DB3754005452        9   127:30:57   
v24dc1    v24-vm1.citrusleaf.local:3000   BB9117BC5005452    192.168.120.215:3000   E-3.11.1.1         4   1AB3C17DED7E91E8   True        BB9DB3754005452        9   125:13:00   
v24dc1    v24-vm6.citrusleaf.local:3000   BB9978A08005452    192.168.120.211:3000   E-3.11.1.1         4   1AB3C17DED7E91E8   True        BB9DB3754005452        9   125:13:20   

Answer

This is due to underlying system call that fails to determine the fully qualified domain name (fqdn) based on the ip address. In that case, it will just show the ip address.

This is usually a misconfiguration. If there is an entry in /etc/hosts, then it will return the hostname that matches the ip address. If there is a DNS server (check /etc/resolve.conf), then it will return the fqdn if matched. To confirm, try the ping command. If the ping fails, then it is likely that DNS is not setup correctly:

ping v24-vm2
ping: cannot resolve v24-vm2: Unknown host

This could be caused by the DHCP not configured correctly (e.g. dhclient not sending the hostname) so the hostname does not have an entry in the DNS server.

If you enter the hostname/ip pairs for all the nodes in the cluster in /etc/hosts, then the value will be used first instead of from the DNS server. The output would then be just the hostnames instead of fqdn:

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~Network Information~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
Cluster           Node               Node                     Ip        Build   Cluster            Cluster     Cluster         Principal   Rackaware   Client     Uptime   
   Name              .                 Id                      .            .      Size                Key   Integrity                 .        Mode    Conns          .   
v24dc1    v24-vm1:3000   BB9117BC5005452    192.168.120.215:3000   E-3.11.1.1         4   503A3F26B6B5A16A   True        BB9DB3754005452   none             3   26:23:38   
v24dc1    v24-vm2:3000   *BB9DB3754005452   192.168.120.216:3000   E-3.11.1.1         4   503A3F26B6B5A16A   True        BB9DB3754005452   none             3   26:25:23   
v24dc1    v24-vm6:3000   BB9978A08005452    192.168.120.211:3000   E-3.11.1.1         4   503A3F26B6B5A16A   True        BB9DB3754005452   none             1   26:21:02   
v24dc1    v24-vm7:3000   BB9AC3883005452    192.168.120.188:3000   E-3.11.1.1         4   503A3F26B6B5A16A   True        BB9DB3754005452   none             1   24:11:36   
Number of rows: 4

Keywords

DNS FQDN IP ASADM INFO

Timestamp

03/02/2017