Dnsmasq sends AAAA and MX requests for private ip range to public DNS server, that slow down SSH access to target nodes
Affects | Status | Importance | Assigned to | Milestone | |
---|---|---|---|---|---|
Fuel for OpenStack |
Invalid
|
Low
|
Alexander Arzhanov | ||
7.0.x |
Invalid
|
Low
|
Alexander Arzhanov |
Bug Description
SSH from FUEL Server Really slow when using node names ( >10 Sec), Causing the scripts execution really long time.
but ssh to IP address of node (control/compute) from FUEL is instant.
It was immediately suspected to do with reverse DNS lookup so 'UseDNS no' was set in /etc/ssh/
Later it was discovered that no entry where present in Fuels /etc/hosts for the existing nodes. After manually added this node entries ssh worked without >10 sec delay.
Was originally misfiled as a blueprint:
https:/
Discussion from the blueprint whiteboard:
[Dmitry Borodaenko 2014-10-17] I don't think duplicating IP addressing between DNS and /etc/hosts is a good idea, we should identify and resolve your DNS problem instead.
[Fabrizio Soppelsa 2014-10-20] Such an explosion of names in the hosts file doesn't look as the cleanest workaround... I would instead troubleshoot DNS performances and/or evaluate adding a DNS cache mechanism.
Changed in fuel: | |
status: | Incomplete → Confirmed |
summary: |
- Reverse DNS lookups slow down SSH access to target nodes + Dnsmasq send AAAA and MX requests for private ip range to public DNS + server, that slow down SSH access to target nodes |
summary: |
- Dnsmasq send AAAA and MX requests for private ip range to public DNS + Dnsmasq sends AAAA and MX requests for private ip range to public DNS server, that slow down SSH access to target nodes |
Changed in fuel: | |
status: | Confirmed → Triaged |
tags: | added: low-hanging-fruit |
Changed in fuel: | |
status: | Triaged → Won't Fix |
Michael, please provide more information about what was wrong with your DNS setup.