Make snowman use snowflake directly instead of snowball #3403
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yacovm
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michaelkaplan13
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| sb := newBinarySnowball(alphaPreference, terminationConditions, red) | ||
| require.Equal(red, sb.Preference()) | ||
| require.False(sb.Finalized()) | ||
| sf := newBinarySnowflake(alphaPreference, terminationConditions, red) |
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Why is this test modified? It seems to be a duplicate of TestBinarySnowflake now.
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I'm not sure why this file is being modified. We aren't changing the code that it was previously testing... If we feel like the binarySnowflake struct needs additional coverage shouldn't we be adding new tests to the binary_snowflake_test.go file rather than here?
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Because we aren't deleting the code that this was testing, nnary_snowball.go, why are we deleting the tests?
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Because we aren't deleting the code that this was testing, unary_snowball.go, why are we deleting the tests?
snow/consensus/snowman/mixed_test.go
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| var sm Consensus | ||
| if i%2 == 0 { | ||
| factory := TopologicalFactory{factory: snowball.SnowflakeFactory} | ||
| sm = factory.New() | ||
| } else { | ||
| factory := TopologicalFactory{factory: snowball.SnowballFactory} | ||
| sm = factory.New() | ||
| } | ||
|
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| require.NoError(n.AddNode(t, sm)) |
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nit: Seems like we can cleanup the if block a bit
| var sm Consensus | |
| if i%2 == 0 { | |
| factory := TopologicalFactory{factory: snowball.SnowflakeFactory} | |
| sm = factory.New() | |
| } else { | |
| factory := TopologicalFactory{factory: snowball.SnowballFactory} | |
| sm = factory.New() | |
| } | |
| require.NoError(n.AddNode(t, sm)) | |
| var sbFactory snowball.Factory | |
| if i%2 == 0 { | |
| sbFactory = snowball.SnowflakeFactory | |
| } else { | |
| sbFactory = snowball.SnowballFactory | |
| } | |
| factory := TopologicalFactory{factory: sbFactory} | |
| sm := factory.New() | |
| require.NoError(n.AddNode(t, sm)) |
snow/consensus/snowball/tree_test.go
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| // * | ||
| // 1/ \ | ||
| // R * | ||
| // / \ | ||
| // G B |
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What do the numbers on the edges mean? It seems like they are referencing Snowball counters but we are using snowflake here and not snowball.
yacovm
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Snowball was introduced in order to improve the stability of snowflake, by taking into account the history when returning the preference. However, if deployed with a configuration where the preference is small enough, and a network partition causes a 50-50 split of the stake, it can actually backfire, as described in 6e1a905. Additionally, latest research [1] points out that snowflake suffices for snowman. This commit removes snowball from snowman and adds a test that simulates a mixed network which runs snowman with and without snowball, and ensures that a mixed network still converges. [1] https://arxiv.org/abs/2404.14250 Signed-off-by: Yacov Manevich <yacov.manevich@avalabs.org>
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Why this should be merged
Snowball was introduced in order to improve the stability of snowflake, by taking into account the history when returning the preference.
However, if deployed with a configuration where the preference is small enough, and a network partition causes a 50-50 split of the stake, it can actually backfire, as described in 6e1a905.
Additionally, latest research [1] points out that snowflake suffices for snowman.
[1] https://arxiv.org/abs/2404.14250
How this works
This commit removes snowball from snowman by substituting the snowball factory snowman uses, with a snowflake factory.
How this was tested
Added a test that simulates a mixed network which runs snowman with and without snowball, and ensures that a mixed network still converges.
Also ran a modified node on Fuji and monitored its consensus related metrics, and it seemed functioning well.