SELECT FROM MUTATION FRAGMENTS doesn't work with tablets

[nyh]

When a keyspace has tablets enabled, running SELECT * FROM MUTATION_FRAGMENTS(tab) results in an on-internal-error like:

multishard reader cannot be used on tables with non-static sharding: cql_test_1703071950171.cql_test_1703071950180

The interesting part of the backtrace is

seastar::on_internal_error(seastar::logger&, std::basic_string_view<char, std::char_traits<char> >) at ??:?
read_context::read_context(seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>, seastar::shared_ptr<locator::effective_replication_map const>, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >) at multishard_mutation_query.cc:?
seastar::shared_ptr_count_for<read_context>::shared_ptr_count_for<seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>&, seastar::shared_ptr<locator::effective_replication_map const>&, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr&, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >&>(seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>&, seastar::shared_ptr<locator::effective_replication_map const>&, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr&, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >&) at multishard_mutation_query.cc:?
seastar::future<(anonymous namespace)::mutation_query_result_builder::result_type> do_query<(anonymous namespace)::mutation_query_result_builder>(seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >, seastar::noncopyable_function<(anonymous namespace)::mutation_query_result_builder (compact_mutation_state<(compact_for_sstables)0> const&)>) at multishard_mutation_query.cc:?
seastar::future<std::tuple<seastar::foreign_ptr<seastar::lw_shared_ptr<(anonymous namespace)::mutation_query_result_builder::result_type> >, cache_temperature> > do_query_on_all_shards<(anonymous namespace)::mutation_query_result_builder>(seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >, std::function<(anonymous namespace)::mutation_query_result_builder (query::result_memory_accounter&&, compact_mutation_state<(compact_for_sstables)0> const&)>) at multishard_mutation_query.cc:?
query_mutations_on_all_shards(seastar::sharded<replica::database>&, seastar::lw_shared_ptr<schema const>, query::read_command const&, std::vector<nonwrapping_interval<dht::ring_position>, std::allocator<nonwrapping_interval<dht::ring_position> > > const&, tracing::trace_state_ptr, std::chrono::time_point<seastar::lowres_clock, std::chrono::duration<long, std::ratio<1l, 1000000000l> > >) at multishard_mutation_query.cc:?
replica::mutation_dump::(anonymous namespace)::multi_range_partition_generator::read_next_page() at mutation_dump.cc:?

Can be reproduced by

• test/cql-pytest/run test_select_from_mutation_fragments.py::test_smoke
• test/cql-pytest/run test_select_from_mutation_fragments.py::test_many_partition_scan
• test/cql-pytest/run test_select_from_mutation_fragments.py::test_metadata_and_value
• test/cql-pytest/run test_select_from_mutation_fragments.py::test_many_partitions

(after hacking tablets to be enabled by default, see #16473).

CC @tgrabiec @denesb

[denesb]

multishard_mutation_query.cc doesn't work with tablets at all. This is used to generate the partition-list for range scans. I will have to come up with a tablet-specific way to do this.

[denesb]

No vulnerable versions, no backport required.