store: deprecate GCCount column #7632
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We’re writing to the GCCount column but never read from it in production. It’s only ever used in store validator but even there zero values in garbage-collected columns results in the column being printed at the end of the validation rather than any kind of failure. So really, I’d argue the column doesn’t serve any purpose. Removing the column not only simplifies the code but also allows us to get rid of borsh serialisation of the DBCol enum. This in turn means that now the variants in the enum can be rearranged or deleted without breaking things. Note that I’m not clearing out this column in this commit. I’m planning to introduce an unrelated database migration soon and will do the clearing then.
matklad
approved these changes
Sep 19, 2022
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LGTM!
One question here is whether we need a metric here, and my feeling is that we don't. We generally keep an eye on storage usage, so we'll notice if something goes significantly wrong. And for figuring out what exactly is wrong I'd say just inspecting the database directly would be more fruitful.
| @@ -2327,7 +2312,8 @@ impl<'a> ChainStoreUpdate<'a> { | |||
| store_update.delete(col, key); | |||
| } | |||
| DBCol::BlockHeader => { | |||
| // TODO #3488 | |||
| // TODO(#3488) At the moment header sync needs block headers. | |||
nikurt
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Nov 9, 2022
We’re writing to the GCCount column but never read from it in production. It’s only ever used in store validator but even there zero values in garbage-collected columns results in the column being printed at the end of the validation rather than any kind of failure. So really, I’d argue the column doesn’t serve any purpose. Removing the column not only simplifies the code but also allows us to get rid of borsh serialisation of the DBCol enum. This in turn means that now the variants in the enum can be rearranged or deleted without breaking things. Note that I’m not clearing out this column in this commit. I’m planning to introduce an unrelated database migration soon and will do the clearing then.
|
Let me know the rust and cargo version |
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We’re writing to the GCCount column but never read from it in
production. It’s only ever used in store validator but even there zero
values in garbage-collected columns results in the column being
printed at the end of the validation rather than any kind of failure.
So really, I’d argue the column doesn’t serve any purpose.
Removing the column not only simplifies the code but also allows us to
get rid of borsh serialisation of the DBCol enum. This in turn means
that now the variants in the enum can be rearranged or deleted without
breaking things.
Note that I’m not clearing out this column in this commit. I’m
planning to introduce an unrelated database migration soon and will do
the clearing then.