Previously, the /v1/tenant/:tenant_id/timeline/:timeline_id/do_gc API
call performed a flush and compaction on the timeline before
GC. Change it not to do that, and change all the tests that used that
API to perform compaction explicitly.
The compaction happens at a slightly different point now. Previously,
the code performed the `refresh_gc_info_internal` step first, and only
then did compaction on all the timelines. I don't think that was what
was originally intended here. Presumably the idea with compaction was
to make some old layer files available for GC. But if we're going to
flush the current in-memory layer to disk, surely you would want to
include the newly-written layer in the compaction too. I guess this
didn't make any difference to the tests in practice, but in any case,
the tests now perform the flush and compaction before any of the GC
steps.
Some of the tests might not need the compaction at all, but I didn't
try hard to determine which ones might need it. I left it out from a
few tests that intentionally tested calling do_gc with an invalid
tenant or timeline ID, though.
Temporarily disable `test_seqscans` for remote projects; they acquire
too much space and time. We can try to reenable it back after switching
to per-test projects.
For better ergonomics. I always found it weird that we used UUID to
actually mean a tenant or timeline ID. It worked because it happened
to have the same length, 16 bytes, but it was hacky.
Merge batch_others and batch_pg_regress. The original idea was to
split all the python tests into multiple "batches" and run each batch
in parallel as a separate CI job. However, the batch_pg_regress batch
was pretty short compared to all the tests in batch_others. We could
split batch_others into multiple batches, but it actually seems better
to just treat them as one big pool of tests and use pytest's handle
the parallelism on its own. If we need to split them across multiple
nodes in the future, we could use pytest-shard or something else,
instead of managing the batches ourselves.
Merge test_neon_regress.py, test_pg_regress.py and test_isolation.py
into one file, test_pg_regress.py. Seems more clear to group all
pg_regress-based tests into one file, now that they would all be in
the same directory.
