catalog: Key expression cache by binary version #31206
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The expression cache caches optimized expressions in a persist shard. It uses the environment's deploy generation as part of the key for the cache. The assumption was that two environments with the same deploy generation would always have the same binary version. This assumption would allow two environments with the same deploy generation to safely deserialize each other's expressions, without worrying about backwards and forwards compatibility. This assumption was not correct. Two environments with different binary version can use the same deploy generation as long as one environment never fully completed a deployment. This is especially bad because the expression cache is written to and read from in read-only mode, before a deployment is complete. This commit updates the key of the expression cache to explicitly use the binary version of environmentd so that two environments with the same version can safely deserialize each other's expressions. Fixes #MaterializeInc/database-issues/issues/8917
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WARNING: This commit is going to cause 15-20 seconds of startup time regression in the next release because it will wipe out the expression cache. |
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The expression cache caches optimized expressions in a persist shard. It uses the environment's deploy generation as part of the key for the cache. The assumption was that two environments with the same deploy generation would always have the same binary version. This assumption would allow two environments with the same deploy generation to safely deserialize each other's expressions, without worrying about backwards and forwards compatibility.
This assumption was not correct. Two environments with different binary version can use the same deploy generation as long as one environment never fully completed a deployment. This is especially bad because the expression cache is written to and read from in read-only mode, before a deployment is complete.
This commit updates the key of the expression cache to explicitly use the binary version of environmentd so that two environments with the same version can safely deserialize each other's expressions.
Fixes #MaterializeInc/database-issues/issues/8917
Motivation
This PR fixes a recognized bug.
Checklist
$T ⇔ Proto$Tmapping (possibly in a backwards-incompatible way), then it is tagged with aT-protolabel.