Bug 1691581

Summary: [OSP 13] nova-novncproxy does not handle TCP RST cleanly when using SSL
Product: Red Hat OpenStack Reporter: Joshua Padman <jpadman>
Component: openstack-novaAssignee: melanie witt <mwitt>
Status: CLOSED NOTABUG QA Contact: OSP DFG:Compute <osp-dfg-compute>
Severity: medium Docs Contact:
Priority: medium    
Version: 13.0 (Queens)CC: dasmith, eglynn, jhakimra, kchamart, mbooth, mwitt, nova-maint, sbauza, sgordon, vromanso
Target Milestone: ---Keywords: Triaged, ZStream
Target Release: ---   
Hardware: Unspecified   
OS: Unspecified   
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Story Points: ---
Clone Of: 1691580 Environment:
Last Closed: 2019-04-26 22:23:37 UTC Type: ---
Regression: --- Mount Type: ---
Documentation: --- CRM:
Verified Versions: Category: ---
oVirt Team: --- RHEL 7.3 requirements from Atomic Host:
Cloudforms Team: --- Target Upstream Version:
Embargoed:
Bug Depends On: 1691580, 1693821    
Bug Blocks:    

Description Joshua Padman 2019-03-22 00:39:34 UTC 
+++ This bug was initially created as a clone of Bug #1691580 +++

The following is paraphrased from the upstream bug report.
https://bugs.launchpad.net/nova/+bug/1816727/

This should be considered a security hardening bug as it could lead to a denial of service situation. It has been determined the same upstream.

Description of problem (nova-novncproxy):
With haproxy acting as a load balancer, but not terminating SSL. 

With that health check enabled, it was found the nova-novncproxy process CPU spiking and eventually causing the node to hang. 

It seems that the haproxy health checks initiate an SSL connection but then immediately send a TCP RST.

For most services this does not seem to be an issue, but for nova-novncproxy it repeatedly initializes NovaProxyRequestHandler which creates a full nova.compute.rpcapi.ComputeAPI instance which very quickly starts to consume significant CPU and overtake the host.
Comment 1 melanie witt 2019-04-26 22:23:37 UTC 
This bug does not exist in nova version <= queens.