Fix retry for UniqueConstraintViolation in RouteCreate (v3) #3697
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philippthun
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The creation of internal routes depends on finding the next vip_offset.
When creating multiple routes in parallel, they find the same vip_offset
and only the very first write operation succeeds. All the others fail
with a UniqueConstraintViolation error. For this error a retry is
triggered in the VCAP::CloudController::RouteCreate action (v3).
This retry did not work due to a bug ("undefined local variable or
method 'user_audit_info'"). Besides fixing this bug a test has been
added to ensure that the parallel creation of internal routes is
working.
When running 5 parallel threads and each thread is creating an internal
route, the following logs are produced:
Duplicate entry '1' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '1' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '1' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '1' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '2' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '2' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '2' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '3' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '3' for key 'routes.routes_vip_offset_index', retrying
Duplicate entry '4' for key 'routes.routes_vip_offset_index', retrying
This indicates that all the write operations are being executed at the
same point in time and only one of them succeeds whereas the others are
failing, i.e. 4 out of 5. For each retry there is one conflicting route
less, so the number of errors goes down from 4 to 3 to 2 to 1 until the
last route could be saved (after 4 retries).
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tcdowney
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Mar 28, 2024
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This looks good to me.
My question is, why are we even assigning VIPs to internal routes anymore? I thought that was something for Istio Copilot.
🤔 https://www.pivotaltracker.com/story/show/161849240
Update: Created #3712 to track that.
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The creation of internal routes depends on finding the next
vip_offset. When creating multiple routes in parallel, they find the samevip_offsetand only the very first write operation succeeds. All the others fail with aUniqueConstraintViolationerror. For this error a retry is triggered in theVCAP::CloudController::RouteCreateaction (v3).This retry did not work due to a bug (
undefined local variable or method 'user_audit_info'). Besides fixing this bug a test has been added to ensure that the parallel creation of internal routes is working.When running 5 parallel threads and each thread is creating an internal route, the following logs are produced:
This indicates that all the write operations are being executed at the same point in time and only one of them succeeds whereas the others are failing, i.e. 4 out of 5. For each retry there is one conflicting route less, so the number of errors goes down from 4 to 3 to 2 to 1 until the last route could be saved (after 4 retries).
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I have made this pull request to the
mainbranchI have run all the unit tests using
bundle exec rakeI have run CF Acceptance Tests