** Description changed:

- haproxy is releasing a feature that provides for seamless reloads for
- 1.8.
+ Reloading haproxy causes TCP resets for active connections.  This can be
+ a serious issue for clouds that rely on haproxy for load balancing, and
+ as a result are restarting it frequently.
  
  Full related blog post is here.
  
https://www.haproxy.com/blog/truly-seamless-reloads-with-haproxy-no-more-hacks/
  
- I have attempted a backport of the feature, and attached it.  The patch
- needs to be cleaned up, needs dep-3 tags, and needs to be tested.  At
- this point I'm mostly just sure that it builds.
+ FFE Justification
+ - Description- The patchset fixes the issue by adding the -x option to 
haproxy.  This option is used for passing the unix stats socket from the old 
haproxy to the new one.  The old haproxy then passes connections to the new 
haproxy using this socket *(simplified explanation).  The changes are largely 
isolated to new functions that implement this functionality.  
+ 
+ - Rationale - The change is largely isolated to the new option, but for
+ those running clouds this could be potentially very important.  Clouds
+ that are "doing it right", and treating instances as cattle are
+ constantly tearing down and rebuilding instances.  This has the side
+ effect of constantly reloading haproxy.  For example at Indeed on a few
+ of our clouds haproxy gets restarted roughly every second.  My tests
+ show that this causes a connection reset rate of about 18 resets for 50k
+ connections.  The haproxy teams are showing 11 tcp resets for 2k
+ connections.  Either way it's greater than 0 and it's dependent on how
+ many connections you receive and how fast you are restarting haproxy.
+ I've chosen not to enable this by default in the systemd unit files, as
+ enabling that the stats socket in the haproxy config match the one
+ passed with the -x command.  However for those that are seeing this
+ problem only having to make the config and unit file changes should be a
+ better user experience than hand building packages.

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https://bugs.launchpad.net/bugs/1712925

Title:
  FFE: HAproxy dropping connections (RST) during config reload / support
  seamless reload

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