Is there a way to allow more than 5 concurrent connections to administrators?
AFAIK those 5 sessions are extra for administrators. If your maxclientsessions limit is 0 then you can have 5 connections PER NODE.
Please set higher maxclientsession limit and check if you can have more concurrent sessions.
This might help: https://my.vertica.com/docs/8.1.x/HTML/index.htm#Authoring/AdministratorsGuide/ManagingClientConnections/SetClientConnections.htm?TocPath=Administrator's%20Guide|Managing%20Client%20Connections|_____1
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