The idea behind readers/ is that each reader has its minimal header with
just a factory method declaration. The delegating reader is defined in
the factory header because it has a derived class in row_cache_test.cc.
Move the definition to delegating_impl.hh so users not interested in
deriving from it don't pay the price in header include cost.
Instead of raising std::runtime_error("Dangling queue_reader_handle_v2")
unconditionally. push() already raises _ex if set, best to be
consistent.
Unconditionally raising std::runtime_error can cause an error to be
logged, when aborting an operation involving a queue reader.
Although the original exception passed to
queue_reader_handle_v2::abort() is most likely handled by higher level
code (not logged), the generic std::runtime_error raised is not and
therefore is logged.
Fixes: #23550Closesscylladb/scylladb#23554
these unused includes were identified by clang-include-cleaner. after
auditing these source files, all of the reports have been confirmed.
in which, instead of using `seastarx.hh`, `readers/mutation_reader.hh`,
use `using seastar::future` to include `future` in the global namespace,
this makes `readers/mutation_reader.hh` a header exposing `future<>`,
but this is not a good practice, because, unlike `seastarx.hh` or
`seastar/core/future.hh`, `reader/mutation_reader.hh` is not
responsible for exposing seastar declarations. so, we trade the
using statement for `#include "seastarx.hh"` in that file to decouple
the source files including it from this header because of this statement.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22439
these unused includes are identified by clang-include-cleaner. after
auditing the source files, all of the reports have been confirmed.
please note, because `mutation/mutation.hh` does not include
`seastar/coroutine/maybe_yield.hh` anymore, and quite a few source
files were relying on this header to bring in the declaration of
`maybe_yield()`, we have to include this header in the places where
this symbol is used. the same applies to `seastar/core/when_all.hh`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
std::ranges::{push,pop}_heap() will only generate default comparator if
the compared types are fully ordered. So we need to pass std::less<>
explicitely as comparator for the code to compile.
From boost::iterator_range<>. One return in maybe_produce_batch() had to
be adjusted because it used a strange initialization of
boost::iterator_range<>, which should not even had compiled.
Calculate a buffer fill hint and pass it to
shard_reader_v2::fill_buffer(), so the underlying buffer-fill can be
optimized to avoid multiple cross shard round-trips, as well as possible
evict-recreate cycles.
The buffer hint mechanism is opt-in, enabled via the new
multishard_reader_buffer_hint parameter.
When the hint is provided, respect it: make sure the returned buffer is
of the requested size, stopping early if the stop_token is seen.
To reduce the amount of possible eviction-recreate cycles while the
buffer is filled, disable auto-pause for the duration of the
fill_reader_buffer() call. For this purpose, auto_pause_disable_guard is
added to evictable_reader_v2.
The hint will tell the shard reader exactly how much data to produce, to
avoid multiple cross-shard round-trips and possible evict-recreate
cycles.
The hint is neither used yet or calculated yet, this is coming in the
next patches.
To reduce the dependency load, replace use of boost ranges
with the std equivalent.
Files that lost the indirect boost dependency have it added as a
direct dependency.
All the overloaded make_combined_reader functions accept an optional
pointer to combined_reader_statistics, to be propagated down through
merging_reader to mutation_fragment_merger. By default, a null pointer
is propagated.
The maximum reader count allows to predict the number of readers
that can be created with create_new_readers(). This helps to
correctly allocate a vector size in the rows_merged statistics
when a combiner reader is created via make_combined_reader.
The mutation_fragment_merger takes one additional parameter in its
constructor, that is a pointer to a combined_reader_statistics
used to collect various statistics.
The histogram is populated with data while the merger consumes
batches from the producer and merges them into seperate mutation
fragments. The size of the batch, that represents the number of streams
the mutation fragment originates from, is used as a key in the
historgam and its corresponding value is increased by one.
Passing an admitted permit -- i.e. one with count resources on it -- to
the multishard reader, will possibly result in a deadlock, because the
permit of the multishard reader is destroyed after the permits of its
child readers. Therefore its semaphore resources won't be automatically
released until children acquire their own resources.
This creates a dependency (an edge in the "resource allocation graph"),
where the semaphore used by the multishard reader depends on the
semaphores used by children. When such dependencies create a cycle, and
permits are acquired by different reads in just the right order, a
deadlock will happen.
Users of the multishard reader have to be aware of this gotcha -- and of
course they aren't. This is small wonder, considering that not even the
documentation on the multishard reader mentions this problem.
To work around this, the user has to call
`reader_permit::release_base_resources()` on the permit, before passing
it to the multishard reader.
On multiple occasions, developers (including the very author of the
multishard reader), forgot or didn't know about this and this resulted
in deadlocks down the line.
This is a design-flaw of the multishard reader, which is addressed in
this patch, after which, it is safe to pass admitted or not admitted
permits to the multishard reader, it will handle the call to
`release_base_resources()` if needed.
* seastar ec5da7a6...69f88e2f (38):
> build: s/Sanitizers_COMPILER_OPTIONS/Sanitizers_COMPILE_OPTIONS
> test: Update httpd test with request/reply body writing sugar
> http: Add sugar to request and response body writers
> utils: Add util::write_to_stream() helper
> seastar-addr2line: adjust llvm termination regex
> README.md: add Crimson project
> rpc: conditionally use fmt::runtime() based on SEASTAR_LOGGER_COMPILE_TIME_FMT
> build: check the combination of Sanitizers
> tls: clear session ticket before releasing
> print: remove dead code
> doc/lambda-coroutine-fiasco: reword for better readability
> rpc: fix compilation error caused by fmt::runtime()
> tutorial: explain the use case of rethrow_exception and coroutine::exception
> reactor: print more informative error when io_submit fails
> README.md: note GitHub discussions
> prometheus: `fmt::print` to stringstream directly
> doc: add document for testing with seastar
> seastar/testing: only include used headers
> test: Add abortable http client test cases
> http/client: Add abortable make_request() API method
> http/client: Abort established connections
> http/client: Handle abort source in pool wait
> http/client: Add abort source to factory::make() method
> http/client: Pass abort_source here and there
> http/client: Idnentation fix after previous patch
> http/client: Merge some continuations explicitly
> signal: add seastar signal api
> httpd: remove unused prometheus structs
> print: use fmtlib's fmt::format_string in format()
> rpc: do not use seastar::format() in rpc logger
> treewide: s/format/seastar::format/
> prometheus: sanitize label value for text protocol
> tests: unit test prometheus wire format
> io-tester: Introduce batches to rate-based submission
> io-tester: Generalize issueing request and collecting its result
> io-tester: Cancel intent once
> io-tester: Dont carry rps/parallelism variables over lambdas
> io-tester: Simplify in-flight management
The breaking changes in the seastar submodule necessitate corresponding
modifications in our code. These changes must be implemented together in
a single commit to maintain consistency. So that each commit is buildable.
following changes are included in addition to seastar submodule update:
* instead of passing a `const char*` for the format string, pass a
templated `fmt::format_string<...>`, this depends on the
`seastar::format()` change in seastar.
* explicitly call `fmt::runtime()` if the format string is not a
consteval expression. this depends on the `seastar::format()` change
in seastar. as `seastar::format()` does not accept a plain
`const char*` which is not constexpr anymore.
* pass abort_source to `dns_connection_factory::make()`. this depends on
the change in seastar, which added a `abort_source*` argument to
the pure virtual member function of `connection_factory::make()`.
* call call {fmt,seastar}::format() explicitly. this is a follow up of
3e84d43f, which takes care of all places where we should call
`fmt::format()` and `seastar::format()` explicitly to disambiguate the
`format()` call. but more `format()` call made their way into the source
tree after 3e84d43f. so we need fix them as well.
* include used header in tests
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Update seastar submodule
Please enter the commit message for your changes. Lines starting
Closesscylladb/scylladb#20649
The `consume*()` variants just forward the call to the `_impl` method with the same name. The latter, being a member of `::impl`, will bypass the top level `fill_buffer()`, etc. methods and thus will never call `set_close_required()`. Do this in the top-level `consume*()` methods instead, to ensure a reader, on which only `consume*()` is called, and then is destroyed, will complain as it should (and abort).
Only one place was found in core code, which didn't close the reader: `split_mutation() in `mutation/mutation.cc` and this reader is the "from-mutation" one which has no real close routine. All other places were in tests. All this is to say, there were no real bugs uncovered by this PR.
Fixes#16520
Improvement, no backport required.
Closesscylladb/scylladb#16522
* github.com:scylladb/scylladb:
readers/flat_mutation_reader_v2: call set_close_required() from consume*()
test/boost/sstable_compaction_test: close reader after use
test/boost/repair_test: close reader after use
mutation/mutation: split_mutation(): close reader after use
The `consume*()` variants just forward the call to the `_impl` method
with the same name. The latter, being a member of `::impl`, will bypass
the top level `fill_buffer()`, etc. methods and thus will never call
`set_close_required()`. Do this in the top-level `consume*()` methods
instead, to ensure a reader, on which only `consume*()` is called, and
then is destroyed, will complain as it should (and abort).
operator()() was also missing `set_close_required()`, fix that too.
When purging regular tombstone consult the min_live_timestamp, if available.
This is safe since we don't need to protect dead data from resurrection, as it is already dead.
For shadowable_tombstones, consult the min_memtable_live_row_marker_timestamp,
if available, otherwise fallback to the min_live_timestamp.
If we see in a view table a shadowable tombstone with time T, then in any row where the row marker's timestamp is higher than T the shadowable tombstone is completely ignored and it doesn't hide any data in any column, so the shadowable tombstone can be safely purged without any effect or risk resurrecting any deleted data.
In other words, rows which might cause problems for purging a shadowable tombstone with time T are rows with row markers older or equal T. So to know if a whole sstable can cause problems for shadowable tombstone of time T, we need to check if the sstable's oldest row marker (and not oldest column) is older or equal T. And the same check applies similarly to the memtable.
If both extended timestamp statistics are missing, fallback to the legacy (and inaccurate) min_timestamp.
Fixesscylladb/scylladb#20423Fixesscylladb/scylladb#20424
> [!NOTE]
> no backport needed at this time
> We may consider backport later on after given some soak time in master/enterprise
> since we do see tombstone accumulation in the field under some materialized views workloads
Closesscylladb/scylladb#20446
* github.com:scylladb/scylladb:
cql-pytest: add test_compaction_tombstone_gc
sstable_compaction_test: add mv_tombstone_purge_test
sstable_compaction_test: tombstone_purge_test: test that old deleted data do not inhibit tombstone garbage collection
sstable_compaction_test: tombstone_purge_test: add testlog debugging
sstable_compaction_test: tombstone_purge_test: make_expiring: use next_timestamp
sstable, compaction: add debug logging for extended min timestamp stats
compaction: get_max_purgeable_timestamp: use memtable and sstable extended timestamp stats
compaction: define max_purgeable_fn
tombstone: can_gc_fn: move declaration to compaction_garbage_collector.hh
sstables: scylla_metadata: add ext_timestamp_stats
compaction_group, storage_group, table_state: add extended timestamp stats getters
sstables, memtable: track live timestamps
memtable_encoding_stats_collector: update row_marker: do nothing if missing
before this change, we rely on `using namespace seastar` to use
`seastar::format()` without qualifying the `format()` with its
namespace. this works fine until we changed the parameter type
of format string `seastar::format()` from `const char*` to
`fmt::format_string<...>`. this change practically invited
`seastar::format()` to the club of `std::format()` and `fmt::format()`,
where all members accept a templated parameter as its `fmt`
parameter. and `seastar::format()` is not the best candidate anymore.
despite that argument-dependent lookup (ADT for short) favors the
function which is in the same namespace as its parameter, but
`using namespace` makes `seastar::format()` more competitive,
so both `std::format()` and `seastar::format()` are considered
as the condidates.
that is what is happening scylladb in quite a few caller sites of
`format()`, hence ADT is not able to tell which function the winner
in the name lookup:
```
/__w/scylladb/scylladb/mutation/mutation_fragment_stream_validator.cc:265:12: error: call to 'format' is ambiguous
265 | return format("{} ({}.{} {})", _name_view, s.ks_name(), s.cf_name(), s.id());
| ^~~~~~
/usr/bin/../lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/format:4290:5: note: candidate function [with _Args = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
4290 | format(format_string<_Args...> __fmt, _Args&&... __args)
| ^
/__w/scylladb/scylladb/seastar/include/seastar/core/print.hh:143:1: note: candidate function [with A = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
143 | format(fmt::format_string<A...> fmt, A&&... a) {
| ^
```
in this change, we
change all `format()` to either `fmt::format()` or `seastar::format()`
with following rules:
- if the caller expects an `sstring` or `std::string_view`, change to
`seastar::format()`
- if the caller expects an `std::string`, change to `fmt::format()`.
because, `sstring::operator std::basic_string` would incur a deep
copy.
we will need another change to enable scylladb to compile with the
latest seastar. namely, to pass the format string as a templated
parameter down to helper functions which format their parameters.
to miminize the scope of this change, let's include that change when
bumping up the seastar submodule. as that change will depend on
the seastar change.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Before we add a new, is_shadowable, parameter to it.
And define global `can_always_purge` and `can_never_purge`
functions, a-la `always_gc` and `never_gc`.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
When a reverse slice is provided, it is given in the native reverse
format. Thus the ranges will be returned in the same order as stored
in the slice.
Therefore there is no need to distinguish between get_ranges and
get_native_ranges. The latter one gets dropped and get_ranges returns
ranges in the same order as stored in the slice.
