Preserve TimedPut on penultimate level until it actually expires #12543
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To make sure
TimedPut
are placed on proper tier before and when it becomes eligible for cold tierTimedPut
entries.This PR also fix some bugs in for handling
TimedPut
during compaction:dealing with an edge case when a
TimedPut
entry's internal key is the right bound for penultimate level, the internal key after swapping in its preferred sequence number will fall outside of the penultimate range because preferred sequence number is smaller than its original sequence number. The entry however is still safe to be placed on penultimate level, so we keep track ofTimedPut
entry's original sequence number for this check. The idea behind this is that as long as it's safe for the original key to be placed on penultimate level, it's safe for the entry with swapped preferred sequence number to be placed on penultimate level too. Because we only swap in preferred sequence number when that entry is visible to the earliest snapshot and there is no other data points with the same user key in lower levels. On the other hand, as long as it's not safe for the original key to be placed on penultimate level, we will not place the entry after swapping the preferred seqno on penultimate level either.the assertion that preferred seqno is always bigger than original sequence number may fail if this logic is only exercised after sequence number is zeroed out. We adjust the assertion to handle that case too. In this case, we don't swap in the preferred seqno but will adjust the its type to
kTypeValue
.there was a special case handling for when range deletion may end up incorrectly covering an entry if preferred seqno is swapped in. But it missed the case that if the original entry is already covered by range deletion. The original handling will mistakenly output the entry instead of omitting it.
Test Plan:
./tiered_compaction_test --gtest_filter="PrecludeLastLevelTest.PreserveTimedPutOnPenultimateLevel"
./compaction_iterator_test --gtest_filter="TimedPut"