Previously config entries sharing a kind & name but in different
namespaces could occasionally cause "stuck states" in replication
because the namespace fields were ignored during the differential
comparison phase.
Example:
Two config entries written to the primary:
kind=A,name=web,namespace=bar
kind=A,name=web,namespace=foo
Under the covers these both get saved to memdb, so they are sorted by
all 3 components (kind,name,namespace) during natural iteration. This
means that before the replication code does it's own incomplete sort,
the underlying data IS sorted by namespace ascending (bar comes before
foo).
After one pass of replication the primary and secondary datacenters have
the same set of config entries present. If
"kind=A,name=web,namespace=bar" were to be deleted, then things get
weird. Before replication the two sides look like:
primary: [
kind=A,name=web,namespace=foo
]
secondary: [
kind=A,name=web,namespace=bar
kind=A,name=web,namespace=foo
]
The differential comparison phase walks these two lists in sorted order
and first compares "kind=A,name=web,namespace=foo" vs
"kind=A,name=web,namespace=bar" and falsely determines they are the SAME
and are thus cause an update of "kind=A,name=web,namespace=foo". Then it
compares "<nothing>" with "kind=A,name=web,namespace=foo" and falsely
determines that the latter should be DELETED.
During reconciliation the deletes are processed before updates, and so
for a brief moment in the secondary "kind=A,name=web,namespace=foo" is
erroneously deleted and then immediately restored.
Unfortunately after this replication phase the final state is identical
to the initial state, so when it loops around again (rate limited) it
repeats the same set of operations indefinitely.
Consul's Connect CA documentation mentions future releases will
support a pluggable CA system. This sentence has existed in the docs
for over two years, however there are currently no plans to develop
this feature on the near-term roadmap.
This commit removes this sentence to avoid giving the impression that
this feature will be available in an upcoming release.
* Add NIA Integration Program page
* Update name to Consul-Terraform-Sync and add Tech Preview tags
* Update diagram to include sequence numbers
* Remove Tech Preview tags and Update Images
* Add TF module naming convention, update image and links
* Add a note, update PANW link, and working updates
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Mike Morris
hashicorp-ci
R.B. Boyer
James Light
Kim Ngo
Daniel Nephin
Blake Covarrubias
Jasmine W
Sabeen Syed
Kit Patella
lornasong
Iryna Shustava
Kyle Havlovitz
Ricardo Oliveira
Hans Hasselberg
Jimmy Merritello
Matt Keeler
Luke Kysow