engine: Do not increase error counter on meta mismatch #686

fyrchik · 2023-09-13T08:32:15Z

fyrchik commented

2023-09-13 08:32:15 +00:00

Close #679

It was introduced in 69e1e6ca to help node determine faulty shards.
However, the situation is possible in a real-life scenario:

Object O is evacuated from shard A to B.
Shard A is unmounted because of lower-level errors.
We now have object in meta on A and in blobstor on B. Technically we
have it in meta on shard B too, but we still got the error if B goes
to a degraded mode.

Signed-off-by: Evgenii Stratonikov e.stratonikov@yadro.com

Close #679 It was introduced in 69e1e6ca to help node determine faulty shards. However, the situation is possible in a real-life scenario: 1. Object O is evacuated from shard A to B. 2. Shard A is unmounted because of lower-level errors. 3. We now have object in meta on A and in blobstor on B. Technically we have it in meta on shard B too, but we still got the error if B goes to a degraded mode. Signed-off-by: Evgenii Stratonikov <e.stratonikov@yadro.com>

fyrchik requested review from storage-core-committers 2023-09-13 08:32:22 +00:00

fyrchik requested review from storage-core-developers 2023-09-13 08:32:22 +00:00

fyrchik force-pushed fix-logic-error from 3eebc31e01 to 3fff6af7e1

2023-09-13 08:32:46 +00:00

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acid-ant approved these changes 2023-09-13 11:02:12 +00:00

aarifullin reviewed 2023-09-13 15:08:31 +00:00

pkg/local_object_storage/engine/get.go Outdated

					
				@ -103,3 +104,1 @@

						if it.ShardWithMeta.Shard != nil {

							e.reportShardError(it.ShardWithMeta, "meta info was present, but object is missing",

								it.MetaError, zap.Stringer("address", prm.addr))

						if it.ShardWithMeta.Shard != nil && it.MetaError != nil {

aarifullin commented

2023-09-13 15:08:31 +00:00

Okay. AFAICS this is needed to make sure we are in the situation when A has not been unmounted yet and still has the meta.

I am curios about the situation when B is in the degraded mode and the error is returned.
I only see if !it.HasDegraded && it.ShardWithMeta.Shard == nil check above. Can you explain, please, how do we process the error when it is B and it is the degtaded mode?

Okay. AFAICS this is needed to make sure we are in the situation when `A` has not been unmounted yet and still has the meta. I am curios about the situation when `B` is in the degraded mode and the error is returned. I only see `if !it.HasDegraded && it.ShardWithMeta.Shard == nil` check above. Can you explain, please, how do we process the error when it is B and it is the degtaded mode?

fyrchik commented

2023-09-14 07:08:50 +00:00

Could you refrase a bit? We always return an object if it can be found, but now we just don't increase error counter.

aarifullin marked this conversation as resolved

aarifullin approved these changes 2023-09-13 15:19:19 +00:00

fyrchik force-pushed fix-logic-error from 3fff6af7e1 to c6af4a3ec8

2023-09-14 07:40:20 +00:00

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fyrchik merged commit c6af4a3ec8 into master

2023-09-14 08:09:36 +00:00

fyrchik deleted branch fix-logic-error

2023-09-14 08:09:39 +00:00