no-store_v2: Store ConfState as part of WAL log snapshot #12735
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@@ Coverage Diff @@
## master #12735 +/- ##
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- Coverage 72.76% 70.11% -2.65%
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Files 422 413 -9
Lines 33018 32063 -955
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- Hits 24024 22481 -1543
- Misses 7077 7681 +604
+ Partials 1917 1901 -16
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ptabor
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| func TestNew(t *testing.T) { | ||
| p, err := ioutil.TempDir(os.TempDir(), "waltest") | ||
| p, err := ioutil.TempDir(t.TempDir(), "waltest") |
| @@ -942,6 +941,10 @@ func (w *WAL) Save(st raftpb.HardState, ents []raftpb.Entry) error { | |||
| } | |||
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| func (w *WAL) SaveSnapshot(e walpb.Snapshot) error { | |||
| if err := walpb.ValidateSnapshotForWrite(&e); err != nil { | |||
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Let's say a, b, c
And c as a follower runs this code against a as a leader with old etcd version. Would the follower reject the snapshot from old-versioned leader?
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I think there would be no problem as raft is speaking using raftpb.Snapshot
That always contains
Line 33 in 102c198
with:
Line 26 in 102c198
This validation just makes sure we never forgot to copy the content from raftpb.Snapshot to walpb.Snapshot.
That cannonically happens in server/etcdserver/storage.go (line 59)
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@ptabor +1. Yeah, this is for saving the snap locally.
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@gyuho Shell I merge, or your concern remains ? |
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/cc @xiang90 |
This will (among others) allow etcd-3.6 to not depend on store_v2 .snap files at all, as WAL + db file will be self-sufficient.
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WAL log snapshots used to contain only Term & Index.
That made them diverging from raft.Snapshot metadata that contained ConfState as well
(list of Voters, Listeners, and candidating voters & listeners).
So far lookup of the full ConfState required dive into *.snap file that is reminiscence of store_v2.
I'm working on preparing for decomissioning of store_v2 in 3.6, so in particular etcd-3.5
should be able to run in situation that *.snap files does not exist (to be rollback ready).