Since table_state is a view to a compaction group, it makes sense
to rename it as so.
With upcoming incremental repair, each replica::compaction_group
will be actually two compaction groups, so there will be two
views for each replica::compaction_group.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
We don't guarantee that coordinators will only emit range reads that
span only one tablet.
Consider this scenario:
1) split is about to be finalized, barrier is executed, completes.
2) coordinator starts a read, uses pre-split erm (split not committed to group0 yet)
3) split is committed to group0, all replicas switch storage.
4) replica-side read is executed, uses a range which spans tablets.
We could fix it with two-phase split execution. Rather than pushing the
complexity to higher levels, let's fix incremental selector which should
be able to serve all the tokens owned by a given shard. During split
execution, either of sibling tablets aren't going anywhere since it
runs with state machine locked, so a single read spanning both
sibling tablets works as long as the selector works across tablet
boundaries.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
With upcoming change where table::set_compaction_strategy() might delay
update of sstable set, ICS might temporarily work with sstable set
implementations other than partitioned_sstable_set. ICS relies on
all_sstable_runs() during regular compaction, and today it triggers
bad_function_call exception if not overriden by set implementation.
To remove this strong dependency between compaction strategy and
a particular set implementation, let's provide a default implementation
of all_sstable_runs(), such that ICS will still work until the set
is updated eventually through a process that adds or remove a
sstable.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Interval map is very susceptible to quadratic space behavior when
it's flooded with many entries overlapping all (or most of)
intervals, since each such entry will have presence on all
intervals it overlaps with.
A trigger we observed was memtable flush storm, which creates many
small "L0" sstables that spans roughly the entire token range.
Since we cannot rely on insertion order, solution will be about
storing sstables with such wide ranges in a vector (unleveled).
There should be no consequence for single-key reads, since upper
layer applies an additional filtering based on token of key being
queried.
And for range scans, there can be an increase in memory usage,
but not significant because the sstables span an wide range and
would have been selected in the combined reader if the range of
scan overlaps with them.
Anyway, this is a protection against storm of memtable flushes
and shouldn't be the common scenario.
It works both with tablets and vnodes, by adjusting the token
range spanned by compaction group accordingly.
Fixes#23634.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
The incremental reader selector maintains an unordered_set of
sstables that are already engaged, and uses std::views::filter
to filter those out. It adds the sstable under consideration to the
set, and if addition failed (because it's already in) then it
filters it out.
This breaks if the filter view is executed twice - the first pass
will add every sstable to the set, and the second will consider
every sstable already filtered. This is what happens with
libstdc++ 15 (due to the addition of vector(from_range_t) constructor),
which uses the first pass to calculate the vector size
and the second pass to insert the elements into a correctly-sized
vector.
Fix by open-coding the loop.
Closesscylladb/scylladb#23597
When implementing the copy constructor for `sstable_set` (derived from
`enable_lw_shared_from_this`), we intentionally need the parent's default
constructor rather than its copy constructor. This is because each new
`sstable_set` instance maintains its own reference count and owns a clone
of the source object's implementation (`x._impl->clone()`).
Although this behavior is correct, GCC warns about not calling the parent's
copy constructor. This change explicitly calls the parent's default constructor
to:
1. Silence GCC warnings
2. Clearly document our intention to use the default constructor
3. Follow best practices for constructor initialization
The functionality remains unchanged, but the code is now more explicit about
its design and free of compiler warnings.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#23083
This commit eliminates unused boost header includes from the tree.
Removing these unnecessary includes reduces dependencies on the
external Boost.Adapters library, leading to faster compile times
and a slightly cleaner codebase.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22997
Replace boost::remove_if() with the standard library's std::erase_if() or std::ranges::remove_if() to reduce external dependencies and simplify the codebase. This change eliminates the requirement for boost::range and makes the implementation more maintainable.
---
it's a cleanup, hence no need to backport.
Closesscylladb/scylladb#22788
* github.com:scylladb/scylladb:
service: migrate from boost::range::remove_if() to std::ranges::remove_if
sstable: migrate from boost::remove_if() to std::erase_if()
Replace boost::copy() with the standard library's std::ranges::copy()
to reduce external dependencies and simplify the codebase. This change
eliminates the requirement for boost::range and makes the implementation
more maintainable.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#22789
Replace boost::remove_if() with the standard library's std::erase_if()
to reduce external dependencies and simplify the codebase. This change
eliminates the requirement for boost::range and makes the implementation
more maintainable.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
now that we are allowed to use C++23. we now have the luxury of using
`std::ranges::to`.
in this change, we:
- replace `boost::copy_range` to `std::ranges::to`
- remove unused `#include` of boost headers
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21880
Replace boost::make_iterator_range() with std::ranges::subrange.
This change improves code modernization and reduces external dependencies:
- Replace boost::make_iterator_range() with std::ranges::subrange
- Remove boost/range/iterator_range.hpp include
- Improve iterator type detection in interval.hh using std::ranges::const_iterator_t<Range>
This is part of ongoing efforts to modernize our codebase and minimize
external dependencies.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21787
now that we are allowed to use C++23. we now have the luxury of using
`std::views::transform`.
in this change, we:
- replace `boost::adaptors::transformed` with `std::views::transform`
- use `fmt::join()` when appropriate where `boost::algorithm::join()`
is not applicable to a range view returned by `std::view::transform`.
- use `std::ranges::fold_left()` to accumulate the range returned by
`std::view::transform`
- use `std::ranges::fold_left()` to get the maximum element in the
range returned by `std::view::transform`
- use `std::ranges::min()` to get the minimal element in the range
returned by `std::view::transform`
- use `std::ranges::equal()` to compare the range views returned
by `std::view::transform`
- remove unused `#include <boost/range/adaptor/transformed.hpp>`
- use `std::ranges::subrange()` instead of `boost::make_iterator_range()`,
to feed `std::views::transform()` a view range.
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
limitations:
there are still a couple places where we are still using
`boost::adaptors::transformed` due to the lack of a C++23 alternative
for `boost::join()` and `boost::adaptors::uniqued`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21700
Modernize the codebase by replacing Boost range adaptors with C++23 standard library views,
reducing external dependencies and leveraging modern C++ language features.
Key Changes:
- Replace `boost::adaptors::filtered` with `std::views::filter`
- Remove `#include <boost/range/adaptor/filtered.hpp>`
- Utilize standard library range views
Motivation:
- Reduce project's external dependency footprint
- Leverage standard library's range and view capabilities
- Improve long-term code maintainability
- Align with modern C++ best practices
Implementation Challenges and Considerations:
1. Range Conversion and Move Semantics
- `std::ranges::to` adaptor requires rvalue references
- Necessitated updates to variable and parameter constness
- Example: `cql3/restrictions/statement_restrictions.cc` modified to remove `const`
from `common` to enable efficient range conversion
2. Range Iteration and Mutation
- Range views may mutate internal state during iteration
- Cannot pass ranges by const reference in some scenarios
- Solution: Pass ranges by rvalue reference to explicitly indicate
state invalidation
Limitations:
- One instance of `boost::adaptors::filtered` temporarily preserved
due to lack of a C++23 alternative for `boost::join()`
- A comprehensive replacement will be addressed in a follow-up change
This change is part of our ongoing effort to modernize the codebase,
reducing external dependencies and adopting modern C++ practices.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21648
Expose the integrity option of the sstable reader factories to the
corresponding sstable_set factories, namely:
* `sstable_set::make_local_shard_sstable_reader()`
* `sstable_set::make_full_scan_reader()`
* `sstable_set::make_range_sstable_reader()`
This is needed to support integrity checking in compaction.
Signed-off-by: Nikos Dragazis <nikolaos.dragazis@scylladb.com>
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.
now that we are allowed to use C++23. we now have the luxury of using
`std::views::values`.
in this change, we:
- replace `boost::adaptors::map_values` with `std::views::values`
- update affected code to work with `std::views::values`
- the places where we use `boost::join()` are not changed, because
we cannot use `std::views::concat` yet. this helper is only
available in C++26.
to reduce the dependency to boost for better maintainability, and
leverage standard library features for better long-term support.
this change is part of our ongoing effort to modernize our codebase
and reduce external dependencies where possible.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#21265
The pointer to combined_reader_statistics is propagated down to
make_combined_reader in order to collect statistics. By default,
a null pointer is propagated.
Note that in case the pointer is valid and the sstable_set consists
of exactly one sstable, statistics are skipped as all rows originate
from exactly a single sstable file.
The existing optimization is crucial f75154afca
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.
When generating readers for the set of sstables, the end size of this
vector is known in advance and its storage can be reserved.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#21055
Using the standard library is preffered over boost.
In cql3/expr/expression.cc to_sorted_vector got more of a
face-list and was modernized to use also std::unique
and while at it, to move its input range in the uniquely sorted
result vector.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
"crawling" is a little bit obscure in this context. so let's rename this
class to reflect the fact that this reader only reads the entire content
of the sstable.
both crawling reader for kl and mx formats are renamed. also, in order
to be consistent, all "crawling reader" in variable names are updated
as well.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
assert() is traditionally disabled in release builds, but not in
scylladb. This hasn't caused problems so far, but the latest abseil
release includes a commit [1] that causes a 1000 insn/op regression when
NDEBUG is not defined.
Clearly, we must move towards a build system where NDEBUG is defined in
release builds. But we can't just define it blindly without vetting
all the assert() calls, as some were written with the expectation that
they are enabled in release mode.
To solve the conundrum, change all assert() calls to a new SCYLLA_ASSERT()
macro in utils/assert.hh. This macro is always defined and is not conditional
on NDEBUG, so we can later (after vetting Seastar) enable NDEBUG in release
mode.
[1] 66ef711d68Closesscylladb/scylladb#20006
flat_mutation_reader_v2 was introduced in a pair of commits in 2021:
e3309322c3 "Clone flat_mutation_reader related classes into v2 variants"
08b5773c12 "Adapt flat_mutation_reader_v2 to the new version of the API"
as a replacement for flat_mutation_reader, using range_tombstone_change
instead of range_tombstone to represent represent range tombstones. See
those commits for more information.
The transition was incremental; the last use of the original
flat_mutation_reader was removed in 2022 in commit
026f8cc1e7 "db: Use mutation_partition_v2 in mvcc"
In turn, flat_mutation_reader was introduced in 2017 in commit
748205ca75 "Introduce flat_mutation_reader"
To transition from a mutation_reader that nested rows within
a partition in a separate stream, to a flat reader that streamed
partitions and rows in the same stream.
Here, we reclaim the original name and rename the awkward
flat_mutation_reader_v2 to mutation_reader.
Note that mutation_fragment_v2 remains since we still use the original
for compatibilty, sometimes.
Some notes about the transition:
- files were also renamed. In one case (flat_mutation_reader_test.cc), the
rename target already existed, so we rename to
mutation_reader_another_test.cc.
- a namespace 'mutation_reader' with two definitions existed (in
mutation_reader_fwd.hh). Its contents was folded into the mutation_reader
class. As a result, a few #includes had to be adjusted.
Closesscylladb/scylladb#19356
incremental_reader_selector is the mechanism for incremental comsumption
of disjoint sstables on range reads.
tablet_sstable_set was implemented, such that selector is efficient with
tablets.
The problem is selector is vnode addicted and will only consider a given
set exhausted when maximum token is reached.
With tablets, that means a range read on first tablet of a given shard
will also consume other tablets living in the same shard. That results
in combined reader having to work with empty sstable readers of tablets
that don't intersect with the range of the read. It won't cause extra
I/O because the underlying sstables don't intersect with the range of
the read. It's only unnecessary CPU work, as it involves creating
readers (= allocation), feeding them into combined reader, which will
in turn invoke the sstable readers only to realize they don't have any
data for that range.
With 100k tablets (ranges), and 100 tablets per shard, and ~5 sstables
per tablet, there will be this amount of readers (empty or not):
(100k * ((100^2 + 100) / 2) * avg_sstable_per_tablet=5) = ~2.5 billions.
~5000 times more readers, it can be quite significant additional cpu
work, even though I/O dominates the most in scans. It's an inefficiency
that we rather get rid of.
The behavior can be observed from logs (there's 1 sstable for each of
4 tablets, but note how readers are created for every single one of
them when reading only 1 tablet range):
```
table - make_reader_v2 - range=(-inf, {-4611686018427387905, end}]
incremental_reader_selector - create_new_readers(null): selecting on pos {minimum token, w=-1}
sstable - make_reader - reader on (-inf, {-4611686018427387905, end}] for sst 3gfx_..._34qn42... that has range [{-9151620220812943033, start},{-4813568684827439727, end}]
incremental_reader_selector - create_new_readers(null): selecting on pos {-4611686018427387904, w=-1}
sstable - make_reader - reader on (-inf, {-4611686018427387905, end}] for sst 3gfx_..._368nk2... that has range [{-4599560452460784857, start},{-78043747517466964, end}]
incremental_reader_selector - create_new_readers(null): selecting on pos {0, w=-1}
sstable - make_reader - reader on (-inf, {-4611686018427387905, end}] for sst 3gfx_..._38lj42... that has range [{851021166589397842, start},{3516631334339266977, end}]
incremental_reader_selector - create_new_readers(null): selecting on pos {4611686018427387904, w=-1}
sstable - make_reader - reader on (-inf, {-4611686018427387905, end}] for sst 3gfx_..._3dba82... that has range [{5065088566032249228, start},{9215673076482556375, end}]
```
Fix is about making sure the tablet set won't select past the
supplied range of the read.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#18556
When a sstable set is cloned, we don't want a change in cloned set
propagating to the former one.
It happens today with partitioned_sstable_set::_all_runs, because
sets are sharing ownership of runs, which is wrong.
Let's not violate clone semantics by copying all_runs when cloning.
Doesn't affect data correctness as readers work directly with
sstables, which are properly cloned. Can result in a crash in ICS
when it is estimating pending tasks, but should be very rare in
practice.
Fixes#17878.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#17879
before this change, we always reference the return value of
`make_reader()`, and the return value's type `flat_mutation_reader_v2`
is movable, so we can just pass it by moving away from it.
in this change, instead of using a lambda, let's just have the
return value of it. simpler this way.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16835
The interface is fragile because the user may incorrectly use the
wrong "gc before". Given that sstable knows how to properly calculate
"gc before", let's do it in estimate__d__t__r(), leaving no room
for mistakes.
sstable_run's variant was also changed to conform to new interface,
allowing ICS to properly estimate droppable ratio, using GC before
that is calculated using each sstable's range. That's important for
upcoming tablets, as we want to query only the range that belongs
to a particular tablet in the repair history table.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closesscylladb/scylladb#15931
Define sstable_set_impl::selector_and_schema_t type as a tuple that
contains both a newly created selector and a schema that the selector
is using.
This will allow removal of _schema field from sstable_set class as
the only place it was used was make_incremental_selector.
Signed-off-by: Piotr Jastrzebski <haaawk@gmail.com>
Before this commit the primary key was hashed for bloom filter check
for each sstable.
This commit makes the key be hashed once per sstable set and reused
for bloom filter lookups in all sstables in the set.
I tested this change using perf_simple_query with the following modifications:
1. Create more than one sstable to have sstable set of more than one elements
2. Try to prevent compactions (I wasn't 100% successful)
3. Use a key that's not present to avoid reading from disk
```
diff --git a/test/perf/perf_simple_query.cc b/test/perf/perf_simple_query.cc
index 26dbf1e99..6bd460df2 100644
--- a/test/perf/perf_simple_query.cc
+++ b/test/perf/perf_simple_query.cc
@@ -105,6 +105,8 @@ std::ostream& operator<<(std::ostream& os, const test_config& cfg) {
static void create_partitions(cql_test_env& env, test_config& cfg) {
std::cout << "Creating " << cfg.partitions << " partitions..." << std::endl;
+ // Create 10 sstables each with all the data
+ for (unsigned count = 0; count < 10; ++count) {
for (unsigned sequence = 0; sequence < cfg.partitions; ++sequence) {
if (cfg.counters) {
execute_counter_update_for_key(env, make_key(sequence));
@@ -117,6 +119,7 @@ static void create_partitions(cql_test_env& env, test_config& cfg) {
std::cout << "Flushing partitions..." << std::endl;
env.db().invoke_on_all(&replica::database::flush_all_memtables).get();
}
+ }
}
static int64_t make_random_seq(test_config& cfg) {
@@ -137,8 +140,18 @@ static std::vector<perf_result> test_read(cql_test_env& env, test_config& cfg) {
query += " using timeout " + cfg.timeout;
}
auto id = env.prepare(query).get0();
- return time_parallel([&env, &cfg, id] {
- bytes key = make_random_key(cfg);
+ // Always use the same key that is not present
+ // to make sure we don't read from disk and make
+ // the benchmark CPU bounded.
+ int64_t key_value = 6;
+ bytes key(bytes::initialized_later(), 5*sizeof(key_value));
+ auto i = key.begin();
+ write<uint64_t>(i, key_value);
+ write<uint64_t>(i, key_value);
+ write<uint64_t>(i, key_value);
+ write<uint64_t>(i, key_value);
+ write<uint64_t>(i, key_value);
+ return time_parallel([&env, id, key] {
return env.execute_prepared(id, {{cql3::raw_value::make_value(std::move(key))}}).discard_result();
}, cfg.concurrency, cfg.duration_in_seconds, cfg.operations_per_shard, cfg.stop_on_error);
}
@@ -423,6 +436,10 @@ static std::vector<perf_result> do_cql_test(cql_test_env& env, test_config& cfg)
.with_column("C2", bytes_type)
.with_column("C3", bytes_type)
.with_column("C4", bytes_type)
+ // Try to prevent compaction
+ // to keep the number of sstables high
+ .set_compaction_enabled(false)
+ .set_min_compaction_threshold(2000000000)
.build();
}).get();
@@ -539,6 +556,11 @@ int scylla_simple_query_main(int argc, char** argv) {
const auto enable_cache = app.configuration()["enable-cache"].as<bool>();
std::cout << "enable-cache=" << enable_cache << '\n';
db_cfg->enable_cache(enable_cache);
+ // Try to prevent compaction
+ // to keep the number of sstables high
+ db_cfg->concurrent_compactors(1);
+ db_cfg->compaction_enforce_min_threshold(true);
+ db_cfg->compaction_throughput_mb_per_sec(1);
cql_test_config cfg(db_cfg);
return do_with_cql_env_thread([&app] (auto&& env) {
```
The following command showed 2-3% improvement on my machine but this
depends on the lenght of the key and the number of sstables in the set.
```
./build/release/scylla perf-simple-query --bypass-cache --flush -c 1
--random-seed=2068087418 --enable-cache false
```
Signed-off-by: Piotr Jastrzebski <haaawk@gmail.com>
Closesscylladb/scylladb#15538
Users of all_sstable_runs() don't want to mutate the runs, but rather
work with their content. So let's avoid copy and make the intention
explicit with the new frozen_sstable_run used as return type
for the interface.
This will guarantee that ICS will be able to fetch uncompacting
runs efficiently.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
This interface selects all runs that store at least one of the
sstables in the vector.
But that's very fragile, to the point that even ICS had to
stop using it. A better interface is to return all runs
managed by the set and allow compaction manager to do its
filtering.
We want to use it in ICS to avoid the overhead of rebuilding
sstable runs which may be expensive as sorting is performed
to guarantee the disjoint invariant.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
and use that in compaction_group, rather than
respective accumulators of its own.
bytes_on_disk is implemented by each sstable_set_impl
and is update on insert and erase (whether directly
into the sstable_set_impl or via the sstable_set).
Although compound_sstable_set doesn't implement
insert and erase, it override `bytes_on_disk()` to return
the sum of all the underlying `sstable_set::bytes_on_disk()`.
Also, added respective unit tests for `partitioned_sstable_set`
and `time_series_sstable_set`, that test each type's
bytes_on_disk, including cloning of the set, and the
`compound_sstable_set` bytes_on_disk semantics.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Add a reader that will automatically close the underlying sstable
reader if fast forward is called with a range past the range
spanned by the SSTable. This is only to be used in the context
of fast forward calls in cleanup, as combined reader in full
scans can proactively close the readers that returned EOS.
Regular reads that go through cache enable fast forwarding to
position range, therefore won't enable auto-closed reader.
Compactions don't enable any kind of forward, and they won't
have it enabled either.
The overhead is minimal, with cleanup being able to reach the
same 38MB/s as before this patch.
Refs #12998.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
View building from staging creates a reader from scratch (memtable
+ sstables - staging) for every partition, in order to calculate
the diff between new staging data and data in base sstable set,
and then pushes the result into the view replicas.
perf shows that the reader creation is very expensive:
+ 12.15% 10.75% reactor-3 scylla [.] lexicographical_tri_compare<compound_type<(allow_prefixes)0>::iterator, compound_type<(allow_prefixes)0>::iterator, legacy_compound_view<compound_type<(allow_prefixes)0> >::tri_comparator::operator()(managed_bytes_basic_view<(mutable_view)0>, managed_bytes
+ 10.01% 9.99% reactor-3 scylla [.] boost::icl::is_empty<boost::icl::continuous_interval<compatible_ring_position_or_view, std::less> >
+ 8.95% 8.94% reactor-3 scylla [.] legacy_compound_view<compound_type<(allow_prefixes)0> >::tri_comparator::operator()
+ 7.29% 7.28% reactor-3 scylla [.] dht::ring_position_tri_compare
+ 6.28% 6.27% reactor-3 scylla [.] dht::tri_compare
+ 4.11% 3.52% reactor-3 scylla [.] boost::icl::interval_base_map<boost::icl::interval_map<compatible_ring_position_or_view, std::unordered_set<seastar::lw_shared_ptr<sstables::sstable>, std::hash<seastar::lw_shared_ptr<sstables::sstable> >, std::equal_to<seastar::lw_shared_ptr<sstables::sst+ 4.09% 4.07% reactor-3 scylla [.] sstables::index_consume_entry_context<sstables::index_consumer>::process_state
+ 3.46% 0.93% reactor-3 scylla [.] sstables::sstable_run::will_introduce_overlapping
+ 2.53% 2.53% reactor-3 libstdc++.so.6 [.] std::_Rb_tree_increment
+ 2.45% 2.45% reactor-3 scylla [.] boost::icl::non_empty::exclusive_less<boost::icl::continuous_interval<compatible_ring_position_or_view, std::less> >
+ 2.14% 2.13% reactor-3 scylla [.] boost::icl::exclusive_less<boost::icl::continuous_interval<compatible_ring_position_or_view, std::less> >
+ 2.07% 2.07% reactor-3 scylla [.] logalloc::region_impl::free
+ 2.06% 1.91% reactor-3 scylla [.] sstables::index_consumer::consume_entry(sstables::parsed_partition_index_entry&&)::{lambda()#1}::operator()() const::{lambda()#1}::operator()
+ 2.04% 2.04% reactor-3 scylla [.] boost::icl::interval_base_map<boost::icl::interval_map<compatible_ring_position_or_view, std::unordered_set<seastar::lw_shared_ptr<sstables::sstable>, std::hash<seastar::lw_shared_ptr<sstables::sstable> >, std::equal_to<seastar::lw_shared_ptr<sstables::sst+ 1.87% 0.00% reactor-3 [kernel.kallsyms] [k] entry_SYSCALL_64_after_hwframe
+ 1.86% 0.00% reactor-3 [kernel.kallsyms] [k] do_syscall_64
+ 1.39% 1.38% reactor-3 libc.so.6 [.] __memcmp_avx2_movbe
+ 1.37% 0.92% reactor-3 scylla [.] boost::icl::segmental::join_left<boost::icl::interval_map<compatible_ring_position_or_view, std::unordered_set<seastar::lw_shared_ptr<sstables::sstable>, std::hash<seastar::lw_shared_ptr<sstables::sstable> >, std::equal_to<seastar::lw_shared_ptr<sstables::
+ 1.34% 1.33% reactor-3 scylla [.] logalloc::region_impl::alloc_small
+ 1.33% 1.33% reactor-3 scylla [.] seastar::memory::small_pool::add_more_objects
+ 1.30% 0.35% reactor-3 scylla [.] seastar::reactor::do_run
+ 1.29% 1.29% reactor-3 scylla [.] seastar::memory::allocate
+ 1.19% 0.05% reactor-3 libc.so.6 [.] syscall
+ 1.16% 1.04% reactor-3 scylla [.] boost::icl::interval_base_map<boost::icl::interval_map<compatible_ring_position_or_view, std::unordered_set<seastar::lw_shared_ptr<sstables::sstable>, std::hash<seastar::lw_shared_ptr<sstables::sstable> >, std::equal_to<seastar::lw_shared_ptr<sstables::sst
+ 1.07% 0.79% reactor-3 scylla [.] sstables::partitioned_sstable_set::insert
That shows some significant amount of work for inserting sstables
into the interval map and maintaining the sstable run (which sorts
fragments by first key and checks for overlapping).
The interval map is known for having issues with L0 sstables, as
it will have to be replicated almost to every single interval
stored by the map, causing terrible space and time complexity.
With enough L0 sstables, it can fall into quadratic behavior.
This overhead is fixed by not building a new fresh sstable set
when recreating the reader, but rather supplying a predicate
to sstable set that will filter out staging sstables when
creating either a single-key or range scan reader.
This could have another benefit over today's approach which
may incorrectly consider a staging sstable as non-staging, if
the staging sst wasn't included in the current batch for view
building.
With this improvement, view building was measured to be 3x faster.
from
INFO 2023-06-16 12:36:40,014 [shard 0] view_update_generator - Processed keyspace1.standard1: 5 sstables in 963957ms = 50kB/s
to
INFO 2023-06-16 14:47:12,129 [shard 0] view_update_generator - Processed keyspace1.standard1: 5 sstables in 319899ms = 150kB/s
Refs #14089.
Fixes#14244.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
In that level no io_priority_class-es exist. Instead, all the IO happens
in the context of current sched-group. File API no longer accepts prio
class argument (and makes io_intent arg mandatory to impls).
So the change consists of
- removing all usage of io_priority_class
- patching file_impl's inheritants to updated API
- priority manager goes away altogether
- IO bandwidth update is performed on respective sched group
- tune-up scylla-gdb.py io_queues command
The first change is huge and was made semi-autimatically by:
- grep io_priority_class | default_priority_class
- remove all calls, found methods' args and class' fields
Patching file_impl-s is smaller, but also mechanical:
- replace io_priority_class& argument with io_intent* one
- pass intent to lower file (if applicatble)
Dropping the priority manager is:
- git-rm .cc and .hh
- sed out all the #include-s
- fix configure.py and cmakefile
The scylla-gdb.py update is a bit hairry -- it needs to use task queues
list for IO classes names and shares, but to detect it should it checks
for the "commitlog" group is present.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#13963
Currently, partitioned_sstable_set::insert may erase a sstable
from the set inadvertently, if an exception is thrown while
(re-)inserting it.
To prevent that, simply return early after detecting that
insertion didn't took place, based on the unordered_set::insert
result.
This issue is theoretical, as there are no known case
of re-inserting sstables into the partitioned sstable set.
Fixes#14060
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#14061
When erasing a sstable first check if its run_id
exists in _all_runs, otherwise do nothing with
that respect, and then if the run becomes empty
when erasing the last sstable (and it could have been
a single-sstable run from get go), erase the run
from `_all_runs`.
Fixes#14052
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#14054
