The database.hh is the central recursive-headers knot -- it has ~50
includes. This patch leaves only 34 (it remains the champion though).
Similar thing for database.cc.
Both changes help the latter compile ~4% faster :)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210414183107.30374-1-xemul@scylladb.com>
Instead of `mutation_query()` from `mutation_query.hh`. The latter is
about to be retired as we want to migrate all users to
`table::mutation_query()`.
As part of this change, move away from `mutation_query_stage` too. This
brings the code paths of the two query variants closer together, as they
both have an execution stage declared in `database`.
This just causes unneeded and slower recompliations. Instead replace
with forward declarations, or includes of smaller headers that were
incidentally brought in by the one removed. The .cc files that really
need it gain the include, but they are few.
Ref #1.
Closes#8403
Don't allow users to disable MC sstables format any more.
We would like to retire some old cluster features that has been around
for years. Namely MC_SSTABLE and UNBOUNDED_RANGE_TOMBSTONES. To do this
we first have to make sure that all existing clusters have them enabled.
It is impossible to know that unless we stop supporting
enable_sstables_mc_format flag.
Test: unit(dev)
Refs #8352
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Closes#8360
On restart the view schemas are loaded and might contain old
views with an unmarked computed column. We already have code to
update the schema, but before we do it we load the view as is. This
is not desired since once registered, this view version can be used
for writes which is forbidden since we will spot a none computed
column which is in the view's primary key but not in the base table
at all. To solve this, in addition to altering the persistent schema,
we fix the view's loaded schema in place. This is safe since computed
column is just involved in generating a value for this column when
creating a view update so the effect of this manipulation stays
internal.
The second stage of the in place fixing is to persist the
changes made in the in place fixing so the view is ready for
the next node restart in particular the `computed_columns` table.
We extract the logic for fixing the view schema into it's own
logic as we will need to use it in more places in the code.
This makes 'maybe_update_legacy_secondary_index_mv_schema' redundant since
it becomes a two liner wrapper for this logic. We also
remove it here and replace the call to it with the equivalent code.
Evicts objects from caches which reflect sstable content, like the row
cache. In the future, it will also drop the page cache
and sstable index caches.
Unlike lsa/compact, doesn't cause reactor stalls.
The old lsa/compact call invokes memory reclamation, which is
non-preemptible. It also compacts LSA segments, so does more
work. Some use cases don't need to compact LSA segments, just want the
row cache to be wiped.
Message-Id: <20210301120211.36195-1-tgrabiec@scylladb.com>
"
Current storage of cells in a row is a union of vector and set. The
vector holds 5 cell_and_hash's inline, up to 32 ones in the external
storage and then it's switched to std::set. Once switched, the whole
union becomes the waste of space, as it's size is
sizeof(vector head) + 5 * sizeof(cell and hash) = 90+ bytes
and only 3 pointers from it are used (std::set header). Also the
overhead to keep cell_and_hash as a set entry is more then the size
of the structure itself.
Column ids are 32-bit integers that most likely come sequentialy.
For this kind of a search key a radix tree (with some care for
non-sequential cases) can be beneficial.
This set introduces a compact radix tree, that uses 7-bit sub values
from the search key to index on each node and compacts the nodes
themselves for better memory usage. Then the row::_storage is replaced
with the new tree.
The most notable result is the memory footprint decrease, for wide
rows down to 2x times. The performance of micro-benchmarks is a bit
lower for small rows and (!) higer for longer (8+ cells). The numbers
are in patch #12 (spoiler: they are better than for v2)
v3:
- trimmed size of radix down to 7 bits
- simplified the nodes layouts, now there are 2 of them (was 4)
- enhanced perf_mutation to test N-cells schema
- added AVX intra-nodes search for medium-sized nodes
- added .clone_from() method that helped to improve perf_mutation
- minor
- changed functions not to return values via refs-arguments
- fixed nested classes to properly use language constructors
- renamed index_to to key_t to distinguish from node_index_t
- improved recurring variadic templates not to use sentinel argument
- use standard concepts
v2:
- fixed potential mis-compilation due to strict-aliasing violation
- added oracle test (radix tree is compared with std::map)
- added radix to perf_collection
- cosmetic changes (concepts, comments, names)
A note on item 1 from v2 changelog. The nodes are no longer packed
perfectly, each has grown 3 bytes. But it turned out that when used
as cells container most of this growth drowned in lsa alignments.
next todo:
- aarch64 version of 16-keys node search
tests: unit(dev), unit(debug for radix*), pref(dev)
"
* 'br-radix-tree-for-cells-3' of https://github.com/xemul/scylla:
test/memory_footpring: Print radix tree node sizes
row: Remove old storages
row: Prepare row::equal for switch
row: Prepare row::difference for switch
row: Introduce radix tree storage type
row-equal: Re-declare the cells_equal lambda
test: Add tests for radix tree
utils: Compact radix tree
array-search: Add helpers to search for a byte in array
test/perf_collection: Add callback to check the speed of clone
test/perf_mutation: Add option to run with more than 1 columns
test/perf_mutation: Prepare to have several regular columns
test/perf_mutation: Use builder to build schema
Now when the 3rd storage type (radix tree) is all in, old
storage can be safely removed. The result is:
1. memory footprint
sizeof(class row): 112 => 16 bytes
sizeof(rows_entry): 126 => 120 bytes
the "in cache" value depends on the number of cells:
num of cells master patch
1 752 656
2 808 712
3 864 768
4 920 824
5 968 936
6 1136 992
...
16 1840 1672
17 1904 1992 (+88)
18 1976 2048 (+72)
19 2048 2104 (+56)
20 2120 2160 (+40)
21 2184 2208 (+24)
22 2256 2264 ( +8)
23 2328 2320
...
32 2960 2808
After 32 cells the storage switches into rbtree with
24-bytes per-cell overhead and the radix tree improvement
rocketlaunches
64 7872 6056
128 15040 9512
256 29376 18568
2. perf_mutation test is enhanced by this series and the
results differ depending on the number of columns used
tps value
--column-count master patch
1 59.9k 57.6k (-3.8%)
2 59.9k 57.5k
4 59.8k 57.6k
8 57.6k 57.7k <- eq
16 56.3k 57.6k
32 53.2k 57.4k (+7.9%)
A note on this. Last time 1-column test was ~5% worse which
was explained by inline storage of 5 cells that's present on
current implementation and was absent in radix tree.
An attempt to make inline storage for small radix trees
resulted in complete loss of memory footprint gain, but gave
fraction of percent to perf_mutation performance. So this
version doesn't have inline nodes.
The 1.2% improvement from v2 surprisingly came from the
tree::clone_from() which in v2 was work-around-ed by slow
walk+emplace sequence while this version has the optimized
API call for cloning.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The code that creates system keyspace open code a lot of things from
database::create_keyspace(). The patch makes create_keyspace() suitable
for both system and non system keyspaces and uses it to create system
keyspaces as well.
Message-Id: <20210209160506.1711177-1-gleb@scylladb.com>
Refs #6148
Commitlog disk limit was previously a "soft" limit, in that we allowed allocating new segments, even if we were over
disk usage max. This would also cause us sometimes to create new segments and delete old ones, if badly timed in
needing and releasing segments, in turn causing useless disk IO for pre-allocation/zeroing.
This patch set does:
* Make limit a hard limit. If we have disk usage > max, we wait for delete or recycle.
* Make flush threshold configurable. Default is ask for flush when over 50% usage. (We do not wait for results)
* Make flush "partial". We flush X% of the used space (used - thres/2), and make the rp limit accordingly. This means we will try to clear the N oldest segments, not all. I.e. "lighter" flush. Of course, if the CL is wholly dominated by a single CF, this will not really help much. But when > 1 cf is used, it means we can skip those not having unflushed data < req rp.
* Force more eager flush/recycle if we're out of segments
Note: flush threshold is not exposed in scylla config (yet). Because I am unsure of wording, and even if it should.
Note: testing is sparse, esp. in regard to latency/timeouts added in high usage scenarios. While I can fairly easily provoke "stalls" (i.e. forced waiting for segments to free up) with simple C-S, it is hard to say exactly where in a more sane config (I set my limits looow) latencies will start accumulating.
Closes#7879
* github.com:scylladb/scylla:
commitlog: Force earlier cycle/flush iff segment reserve is empty
commitlog: Make segment allocation wait iff disk usage > max
commitlog: Do partial (memtable) flushing based on threshold
commitlog: Make flush threshold configurable
table: Add a flush RP mark to table, and shortcut if not above
The db::update_keyspace() needs sharded<storage_proxy>
reference, but the only caller of it already has it and
can pass one as argument.
tests: unit(dev)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210205175611.13464-3-xemul@scylladb.com>
"
Currently inactive readers are stored in two different places:
* reader concurrency semaphore
* querier cache
With the latter registering its inactive readers with the former. This
is an unnecessarily complex (and possibly surprising) setup that we want
to move away from. This series solves this by moving the responsibility
if storing of inactive reads solely to the reader concurrency semaphore,
including all supported eviction policies. The querier cache is now only
responsible for indexing queriers and maintaining relevant stats.
This makes the ownership of the inactive readers much more clear,
hopefully making Benny's work on introducing close() and abort() a
little bit easier.
Tests: unit(release, debug:v1)
"
* 'unify-inactive-readers/v2' of https://github.com/denesb/scylla:
reader_concurrency_semaphore: store inactive readers directly
querier_cache: store readers in the reader concurrency semaphore directly
querier_cache: retire memory based cache eviction
querier_cache: delegate expiry to the reader_concurrency_semaphore
reader_concurrency_semaphore: introduce ttl for inactive reads
querier_cache: use new eviction notify mechanism to maintain stats
reader_concurrency_semaphore: add eviction notification facility
reader_concurrency_semaphore: extract evict code into method evict()
Adds a second RP to table, marking where we flushed last.
If a new flush request comes in that is below this mark, we
can skip a second flush.
This is to (in future) support incremental CL flush.
Fixes#7732
When truncating with auto_snapshot on, we try to verify the low rp mark
from the CF against the sstables discarded by the truncation timestamp.
However, in a scenario like:
Fill memtables
Flush
Truncate with snapshot A
Fill memtables some more
Truncate
Move snapshot A to upload + refresh (load old tables)
Truncate
The last op will assert, because while we have sstables loaded, which
will be discarded now, we did not in fact generate any _new_ ones
(since memtables are empty), and the RP we get back from discard is
one from an earlier generation set.
(Any permutation of events that create the situation "empty memtable" +
"non-empty sstables with only old tables" will generate the same error).
Added a check that before flushing checks if we actually have any
data, and if not, does not uphold the RP relation assert.
Closes#7799
We already wait for pending reads and writes, so for completeness
we should also wait for all pending stream operations to finish
before dropping the table to avoid inconsistencies.
There are two places that call it -- database code itself and
tests. The former already has the local host id, so just pass
one.
The latter are a bit trickier. Currently they use the value from
storage_service created by storage_service_for_tests, but since
this version of service doesn't pass through prepare_to_join()
the local_host_id value there is default-initialized, so just
default-initialize the needed argument in place.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The method is called after query_processor::execute_internal
to flush the cf. Encapsulating this flush inside database and
getting the database from query_processor lets removing
database reference from global qctx object.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
available_memory is used to seed many caches and controllers. Usually
it's detected from the environment, but unit tests configure it
on their own with fake values. If they forget, then the undefined
behavior sanitizer will kick in in random places (see 8aa842614a
("test: gossip_test: configure database memory allocation correctly")
for an example.
Prevent this early by asserting that available_memory is nonzero.
Closes#7612
Commit e5be3352cf ("database, streaming, messaging: drop
streaming memtables") removed streaming memtables; this removes
the mechanisms to synchronize them: _streaming_flush_gate and
_streaming_flush_phaser. The memory manager for streaming is removed,
and its 10% reserve is evenly distributed between memtables and
general use (e.g. cache).
Note that _streaming_flush_phaser and _streaming_flush_date are
no longer used to syncrhonize anything - the gate is only used
to protect the phaser, and the phaser isn't used for anything.
Closes#7454
This miniseries adds metrics which can help the users detect potential overloads:
* due to having too many in-flight hints
* due to exceeding the capacity of the read admission queue, on replica side
Closes#7584
* github.com:scylladb/scylla:
reader_concurrency_semaphore: add metrics for shed reads
storage_proxy: add metrics for too many in-flight hints failures
When the admission queue capacity reaches its limits, excessive
reads are shed in order to avoid overload. Each such operation
now bumps the metrics, which can help the user judge if a replica
is overloaded.
To facilitate that, keep a const shared_token_metadata& in class database
rather than a const token_metadata&
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
And use it to get a token_metadata& compatible
with current usage, until the services are converted to
use token_metadata_ptr.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Users can change `durable_writes` anytime with ALTER KEYSPACE.
Cassandra reads the value of `durable_writes` every time when applying
a mutation, so changes to that setting take effect immediately. That is,
mutations are added to the commitlog only when `durable_writes` is `true`
at the moment of their application.
Scylla reads the value of `durable_writes` only at `keyspace` construction time,
so changes to that setting take effect only after Scylla is restarted.
This patch fixes the inconsistency.
Fixes#3034Closes#7533
This patch introduces a new system table: `system.scylla_table_schema_history`,
which is used to keep track of column mappings for obsolete table
schema versions (i.e. schema becomes obsolete when it's being changed
by means of `CREATE TABLE` or `ALTER TABLE` DDL operations).
It is populated automatically when a new schema version is being
pulled from a remote in get_schema_definition() at migration_manager.cc
and also when schema change is being propagated to system schema tables
in do_merge_schema() at schema_tables.cc.
The data referring to the most recent table schema version is always
present. Other entries are garbage-collected when the corresponding
table schema version is obsoleted (they will be updated with a TTL equal
to `DEFAULT_GC_GRACE_SECONDS` on `ALTER TABLE`).
In case we failed to persist column mapping after a schema change,
missing entries will be recreated on node boot.
Later, the information from this table is used in `paxos_state::learn`
callback in case we have a mismatch between the most recent schema
version and the one that is stored inside the `frozen_mutation`
for the accepted proposal.
Such situation may arise under following circumstances:
1. The previous LWT operation crashed on the "accept" stage,
leaving behind a stale accepted proposal, which waits to be
repaired.
2. The table affected by LWT operation is being altered, so that
schema version is now different. Stored proposal now references
obsolete schema.
3. LWT query is retried, so that Scylla tries to repair the
unfinished Paxos round and apply the mutation in the learn stage.
When such mismatch happens, prior to that patch the stored
`frozen_mutation` is able to be applied only if we are lucky enough
and column_mapping in the mutation is "compatible" with the new
table schema.
It wouldn't work if, for example, the columns are reordered, or
some columns, which are referenced by an LWT query, are dropped.
With this patch we try to look up the column mapping for
the obsolete schema version, then upgrade the stored mutation
using obtained column mapping and apply an upgraded mutation instead.
* git@github.com:ManManson/scylla.git feature/table_schema_history_v7:
lwt: add column_mapping history persistence tests
schema: add equality operator for `column_mapping` class
lwt: store column_mapping's for each table schema version upon a DDL change
schema_tables: extract `fill_column_info` helper
frozen_mutation: introduce `unfreeze_upgrading` method
This patch introduces a new system table: `system.scylla_table_schema_history`,
which is used to keep track of column mappings for obsolete table
schema versions (i.e. schema becomes obsolete when it's being changed
by means of `CREATE TABLE` or `ALTER TABLE` DDL operations).
It is populated automatically when a new schema version is being
pulled from a remote in get_schema_definition() at migration_manager.cc
and also when schema change is being propagated to system schema tables
in do_merge_schema() at schema_tables.cc.
The data referring to the most recent table schema version is always
present. Other entries are garbage-collected when the corresponding
table schema version is obsoleted (they will be updated with a TTL equal
to `DEFAULT_GC_GRACE_SECONDS` on `ALTER TABLE`).
In case we failed to persist column mapping after a schema change,
missing entries will be recreated on node boot.
Later, the information from this table is used in `paxos_state::learn`
callback in case we have a mismatch between the most recent schema
version and the one that is stored inside the `frozen_mutation`
for the accepted proposal.
Such situation may arise under following circumstances:
1. The previous LWT operation crashed on the "accept" stage,
leaving behind a stale accepted proposal, which waits to be
repaired.
2. The table affected by LWT operation is being altered, so that
schema version is now different. Stored proposal now references
obsolete schema.
3. LWT query is retried, so that Scylla tries to repair the
unfinished Paxos round and apply the mutation in the learn stage.
When such mismatch happens, prior to that patch the stored
`frozen_mutation` is able to be applied only if we are lucky enough
and column_mapping in the mutation is "compatible" with the new
table schema.
It wouldn't work if, for example, the columns are reordered, or
some columns, which are referenced by an LWT query, are dropped.
With this patch we try to look up the column mapping for
the obsolete schema version, then upgrade the stored mutation
using obtained column mapping and apply an upgraded mutation instead.
In case we don't find a column_mapping we just return an error
from the learn stage.
Tests: unit(dev, debug), dtests(paxos_tests.py:TestPaxos.schema_mismatch_*_test)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Require a schema and an operation name to be given to each permit when
created. The schema is of the table the read is executed against, and
the operation name, which is some name identifying the operation the
permit is part of. Ideally this should be different for each site the
permit is created at, to be able to discern not only different kind of
reads, but different code paths the read took.
As not all read can be associated with one schema, the schema is allowed
to be null.
The name will be used for debugging purposes, both for coredump
debugging and runtime logging of permit-related diagnostics.
Allow the evictable reader managing the underlying reader to pass its
own permit to it when creating it, making sure they share the same
permit. Note that the two parts can still end up using different
permits, when the underlying reader is kept alive between two pages of a
paged read and thus keeps using the permit received on the previous
page.
Also adjust the `reader_context` in multishard_mutation_query.cc to use
the passed-in permit instead of creating a new one when creating a new
reader.
Don't create an own permit, take one as a parameter, like all other
readers do, so the permit can be provided by the higher layer, making
sure all parts of the logical read use the same permit.
Although each sstable_directory limits concurrency using
max_concurrent_for_each, there could be a large number
of calls to do_for_each_sstable running in parallel
(e.g per keyspace X per table in the distributed_loader).
To cap parallelism across sstable_directory instances and
concurrent calls to do_for_each_sstable, start a sharded<semaphore>
and pass a shared semaphore& to the sstable_directory:s.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently, sstable_manager is used to create sstables, but it loses track
of them immediately afterwards. This series makes an sstable's life fully
contained within its sstable_manager.
The first practical impact (implemented in this series) is that file removal
stops being a background job; instead it is tracked by the sstable_manager,
so when the sstable_manager is stopped, you know that all of its sstable
activity is complete.
Later, we can make use of this to track the data size on disk, but this is not
implemented here.
Closes#7253
* github.com:scylladb/scylla:
sstables: remove background_jobs(), await_background_jobs()
sstables: make sstables_manager take charge of closing sstables
test: test_env: hold sstables_manager with a unique_ptr
test: drop test_sstable_manager
test: sstables::test_env: take ownership of manager
test: broken_sstable_test: prepare for asynchronously closed sstables_manager
test: sstable_utils: close test_env after use
test: sstable_test: dont leak shared_sstable outside its test_env's lifetime
test: sstables::test_env: close self in do_with helpers
test: perf/perf_sstable.hh: prepare for asynchronously closed sstables_manager
test: view_build_test: prepare for asynchronously closed sstables_manager
test: sstable_resharding_test: prepare for asynchronously closed sstables_manager
test: sstable_mutation_test: prepare for asynchronously closed sstables_manager
test: sstable_directory_test: prepare for asynchronously closed sstables_manager
test: sstable_datafile_test: prepare for asynchronously closed sstables_manager
test: sstable_conforms_to_mutation_source_test: remove references to test_sstables_manager
test: sstable_3_x_test: remove test_sstables_manager references
test: schema_changes_test: drop use of test_sstables_manager
mutation_test: adjust for column_family_test_config accepting an sstables_manager
test: lib: sstable_utils: stop using test_sstables_manager
test: sstables test_env: introduce manager() accessor
test: sstables test_env: introduce do_with_async_sharded()
test: sstables test_env: introduce do_with_async_returning()
test: lib: sstable test_env: prepare for life as a sharded<> service
test: schema_changes_test: properly close sstables::test_env
test: sstable_mutation_test: avoid constructing temporary sstables::test_env
test: mutation_reader_test: avoid constructing temporary sstables::test_env
test: sstable_3_x_test: avoid constructing temporary sstables::test_env
test: lib: test_services: pass sstables_manager to column_family_test_config
test: lib: sstables test_env: implement tests_env::manager()
test: sstable_test: detemplate write_and_validate_sst()
test: sstable_test_env: detemplate do_with_async()
test: sstable_datafile_test: drop bad 'return'
table: clear sstable set when stopping
table: prevent table::stop() race with table::query()
database: close sstable_manager:s
sstables_manager: introduce a stub close()
sstable_directory_test: fix threading confusion in make_sstable_directory_for*() functions
test: sstable_datafile_test: reorder table stop in compaction_manager_test
test: view_build_test: test_view_update_generator_register_semaphore_unit_leak: do not discard future in timer
test: view_build_test: fix threading in test_view_update_generator_register_semaphore_unit_leak
view: view_update_generator: drop references to sstables when stopping
Currently all "database" metrics are registered in a single call to
`metric_groups::add_group()`. As all the metrics to-be-registered are
passed in a single initializer list, this blows up the stack size, to
the point that adding a single new metric causes it to exceed the
currently configured max-stack-size of 13696 bytes. To reduce stack
usage, split the single call in two, roughly in the middle. While we
could try to come up with some logical grouping of metrics and do much
arranging and code-movement I think we might as well just split into two
arbitrary groups, containing roughly the same amount of metrics.
In preparations of non-inactive read stats being added to the semaphore,
rename its existing stats struct and member to a more generic name.
Fields, whose name only made sense in the context of the old name are
adjusted accordingly.
The storage service computes gossiper states before it starts the
gossiper. Among them, node's schema version. There are two problems with that.
First is that computing the schema version and publishing it is not
atomic, so is not safe against concurrent schema changes or schema
version recalculations. It will not exclude with
recalculate_schema_version() calls, and we could end up with the old
(and incorrect) schema version being advertised in gossip.
Second problem is that we should not allow the database layer to call
into the gossiper layer before it is fully initialized, as this may
produce undefined behavior.
The solution for both problems is to break the cyclic dependency
between the database layer and the storage_service layer by having the
database layer not use the gossiper at all. The database layer
publishes schema version inside the database class and allows
installing listeners on changes. The storage_service layer asks the
database layer for the current version when it initializes, and only
after that installs a listener which will update the gossiper.
This also allows us to drop unsafe functions like update_schema_version().
"
There's last call for global storage service left in compaction code, it
comes from cleanup_compaction to get local token ranges for filtering.
The call in question is a pure wrapper over database, so this set just
makes use of the database where it's already available (perform_cleanup)
and adds it where it's needed (perform_sstable_upgrade).
tests: unit(dev), nodetool upgradesstables
"
* 'br-remove-ss-from-compaction-3' of https://github.com/xemul/scylla:
storage_service: Remove get_local_ranges helper
compaction: Use database from options to get local ranges
compaction: Keep database reference on upgrade options
compaction: Keep database reference on cleanup options
db: Factor out get_local_ranges helper
Storage service and repair code have identical helpers to get local
ranges for keyspace. Move this helper's code onto database, later it
will be reused by one more place.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
No need to modify token_metadata form database code.
Also, get rid of mutable get_token_metadata variant.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Contains patch from Rafael to fix up includes.
* seastar c872c3408c...7f7cf0f232 (9):
> future: Consider result_unavailable invalid in future_state_base::ignore()
> future: Consider result_unavailable invalid in future_state_base::valid()
> Merge "future-util: split header" from Benny
> docs: corrected some text and code-examples in streaming-rpc docs
> future: Reduce nesting in future::then
> demos: coroutines: include std-compat.hh
> sstring: mark str() and methods using it as noexcept
> tls: Add an assert
> future: fix coroutine compilation