server: partly fix config entry replication issue that prevents replication in some circumstances #12307
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kisunji
reviewed
Feb 22, 2022
| @@ -214,9 +217,10 @@ func (s *Server) replicateConfig(ctx context.Context, lastRemoteIndex uint64, lo | |||
| return 0, true, nil | |||
| } | |||
| if err != nil { | |||
| return 0, false, fmt.Errorf("failed to delete local config entries: %v", err) | |||
| merr = multierror.Append(merr, err) | |||
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do we want to preserve the error message here?
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the inner errors will be of the form Failed to apply config entry <delete|upsert>: <error with details> so since the delete/update portion was already present I didn't see the value.
| @@ -228,9 +232,14 @@ func (s *Server) replicateConfig(ctx context.Context, lastRemoteIndex uint64, lo | |||
| return 0, true, nil | |||
| } | |||
| if err != nil { | |||
| return 0, false, fmt.Errorf("failed to update local config entries: %v", err) | |||
| merr = multierror.Append(merr, err) | |||
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do we want to preserve the error message here?
kisunji
approved these changes
Feb 23, 2022
…cation in some circumstances There are some cross-config-entry relationships that are enforced during "graph validation" at persistence time that are required to be maintained. This means that config entries may form a digraph at times. Config entry replication procedes in a particular sorted order by kind and name. Occasionally there are some fixups to these digraphs that end up replicating in the wrong order and replicating the leaves (ingress-gateway) before the roots (service-defaults) leading to replication halting due to a graph validation error related to things like mismatched service protocol requirements. This PR changes replication to give each computed change (upsert/delete) a fair shot at being applied before deciding to terminate that round of replication in error. In the case where we've simply tried to do the operations in the wrong order at least ONE of the outstanding requests will complete in the right order, leading the subsequent round to have fewer operations to do, with a smaller likelihood of graph validation errors. This does not address all scenarios, but for scenarios where the edits are being applied in the wrong order this should avoid replication halting. Fixes #9319 The scenario that is NOT ADDRESSED by this PR is as follows: 1. create: service-defaults: name=new-web, protocol=http 2. create: service-defaults: name=old-web, protocol=http 3. create: service-resolver: name=old-web, redirect-to=new-web 4. delete: service-resolver: name=old-web 5. update: service-defaults: name=old-web, protocol=grpc 6. update: service-defaults: name=new-web, protocol=grpc 7. create: service-resolver: name=old-web, redirect-to=new-web If you shutdown dc2 just before (4) and turn it back on after (7) replication is impossible as there is no single edit you can make to make forward progress.
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freddygv
approved these changes
Feb 23, 2022
|
🍒 If backport labels were added before merging, cherry-picking will start automatically. To retroactively trigger a backport after merging, add backport labels and re-run https://circleci.com/gh/hashicorp/consul/594115. |
|
🍒✅ Cherry pick of commit 6427128 onto |
hc-github-team-consul-core
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Feb 23, 2022
…cation in some circumstances (#12307) There are some cross-config-entry relationships that are enforced during "graph validation" at persistence time that are required to be maintained. This means that config entries may form a digraph at times. Config entry replication procedes in a particular sorted order by kind and name. Occasionally there are some fixups to these digraphs that end up replicating in the wrong order and replicating the leaves (ingress-gateway) before the roots (service-defaults) leading to replication halting due to a graph validation error related to things like mismatched service protocol requirements. This PR changes replication to give each computed change (upsert/delete) a fair shot at being applied before deciding to terminate that round of replication in error. In the case where we've simply tried to do the operations in the wrong order at least ONE of the outstanding requests will complete in the right order, leading the subsequent round to have fewer operations to do, with a smaller likelihood of graph validation errors. This does not address all scenarios, but for scenarios where the edits are being applied in the wrong order this should avoid replication halting. Fixes #9319 The scenario that is NOT ADDRESSED by this PR is as follows: 1. create: service-defaults: name=new-web, protocol=http 2. create: service-defaults: name=old-web, protocol=http 3. create: service-resolver: name=old-web, redirect-to=new-web 4. delete: service-resolver: name=old-web 5. update: service-defaults: name=old-web, protocol=grpc 6. update: service-defaults: name=new-web, protocol=grpc 7. create: service-resolver: name=old-web, redirect-to=new-web If you shutdown dc2 just before (4) and turn it back on after (7) replication is impossible as there is no single edit you can make to make forward progress.
|
🍒✅ Cherry pick of commit 6427128 onto |
hc-github-team-consul-core
pushed a commit
that referenced
this pull request
Feb 23, 2022
…cation in some circumstances (#12307) There are some cross-config-entry relationships that are enforced during "graph validation" at persistence time that are required to be maintained. This means that config entries may form a digraph at times. Config entry replication procedes in a particular sorted order by kind and name. Occasionally there are some fixups to these digraphs that end up replicating in the wrong order and replicating the leaves (ingress-gateway) before the roots (service-defaults) leading to replication halting due to a graph validation error related to things like mismatched service protocol requirements. This PR changes replication to give each computed change (upsert/delete) a fair shot at being applied before deciding to terminate that round of replication in error. In the case where we've simply tried to do the operations in the wrong order at least ONE of the outstanding requests will complete in the right order, leading the subsequent round to have fewer operations to do, with a smaller likelihood of graph validation errors. This does not address all scenarios, but for scenarios where the edits are being applied in the wrong order this should avoid replication halting. Fixes #9319 The scenario that is NOT ADDRESSED by this PR is as follows: 1. create: service-defaults: name=new-web, protocol=http 2. create: service-defaults: name=old-web, protocol=http 3. create: service-resolver: name=old-web, redirect-to=new-web 4. delete: service-resolver: name=old-web 5. update: service-defaults: name=old-web, protocol=grpc 6. update: service-defaults: name=new-web, protocol=grpc 7. create: service-resolver: name=old-web, redirect-to=new-web If you shutdown dc2 just before (4) and turn it back on after (7) replication is impossible as there is no single edit you can make to make forward progress.
rboyer
added a commit
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Feb 24, 2022
…ts replication in some circumstances Backport of #12307 to 1.9.x
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There are some cross-config-entry relationships that are enforced during
"graph validation" at persistence time that are required to be
maintained. This means that config entries may form a digraph at times.
Config entry replication proceeds in a particular sorted order by kind
and name.
Occasionally there are some fixups to these digraphs that end up
replicating in the wrong order and replicating the leaves
(ingress-gateway) before the roots (service-defaults) leading to
replication halting due to a graph validation error related to things
like mismatched service protocol requirements.
This PR changes replication to give each computed change (upsert/delete)
a fair shot at being applied before deciding to terminate that round of
replication in error. In the case where we've simply tried to do the
operations in the wrong order at least ONE of the outstanding requests
will complete in the right order, leading the subsequent round to have
fewer operations to do, with a smaller likelihood of graph validation
errors.
This does not address all scenarios, but for scenarios where the edits
are being applied in the wrong order this should avoid replication
halting.
Fixes #9319
The scenario that is NOT ADDRESSED by this PR is as follows:
If you shutdown dc2 just before (4) and turn it back on after (7)
replication is impossible as there is no single edit you can make to
make forward progress.