Over the last few months, the server team has adopted a more conservative approach to backporting changes. In particular, the guidance is that we should only be backporting commits that fix a critical issue. As far as query behavioral changes go, these should only really be applied to master and only backported if they resolve some critical issue. This change has implications for multiversion fuzzer testing on older branches. In particular, given that we don't expect these branches to change very much, the likelihood that multiversion fuzzer testing will uncover bugs is very low.

As such, this ticket proposes replacing query multiversion fuzzer in 7.0, 8.0, 8.2 with a deterministic variant.

Note that we still wish to keep testing master against the latest LTS version, as the likelihood of finding bugs on master remains high given that the overwhelming majority of active development work is being done on master.

According to the "open questions" section of this eng proposal, this ticket should also:

• increase the frequency of query multiversion fuzzer runs on master. This is now a separate ticket SERVER-113151
• ensure that multiversion fuzzers are omitted from newly-created release branches. This has been communicated to the Release Team and they will be opening a ticket for Query Optimization when a new release branch is created. That ticket will describe the actions needed under this bullet point.