The following was seen:
```
!WARNING | scylla[6057]: [shard 12:strm] seastar_memory - oversized allocation: 212992 bytes. This is non-fatal, but could lead to latency and/or fragmentation issues. Please report: at
[Backtrace #0]
void seastar::backtrace<seastar::current_backtrace_tasklocal()::$_0>(seastar::current_backtrace_tasklocal()::$_0&&, bool) at ./build/release/seastar/./seastar/include/seastar/util/backtrace.hh:89
(inlined by) seastar::current_backtrace_tasklocal() at ./build/release/seastar/./build/release/seastar/./seastar/src/util/backtrace.cc:99
seastar::current_tasktrace() at ./build/release/seastar/./build/release/seastar/./seastar/src/util/backtrace.cc:136
seastar::current_backtrace() at ./build/release/seastar/./build/release/seastar/./seastar/src/util/backtrace.cc:169
seastar::memory::cpu_pages::warn_large_allocation(unsigned long) at ./build/release/seastar/./build/release/seastar/./seastar/src/core/memory.cc:848
seastar::memory::allocate_slowpath(unsigned long) at ./build/release/seastar/./build/release/seastar/./seastar/src/core/memory.cc:911
operator new(unsigned long) at ./build/release/seastar/./build/release/seastar/./seastar/src/core/memory.cc:1706
std::allocator<dht::token_range_endpoints>::allocate(unsigned long) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/allocator.h:196
(inlined by) std::allocator_traits<std::allocator<dht::token_range_endpoints> >::allocate(std::allocator<dht::token_range_endpoints>&, unsigned long) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/alloc_traits.h:515
(inlined by) std::_Vector_base<dht::token_range_endpoints, std::allocator<dht::token_range_endpoints> >::_M_allocate(unsigned long) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/stl_vector.h:380
(inlined by) void std::vector<dht::token_range_endpoints, std::allocator<dht::token_range_endpoints> >::_M_realloc_append<dht::token_range_endpoints const&>(dht::token_range_endpoints const&) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/vector.tcc:596
locator::describe_ring(replica::database const&, gms::gossiper const&, seastar::basic_sstring<char, unsigned int, 15u, true> const&, bool) at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/bits/stl_vector.h:1294
std::__n4861::coroutine_handle<seastar::internal::coroutine_traits_base<std::vector<dht::token_range_endpoints, std::allocator<dht::token_range_endpoints> > >::promise_type>::resume() const at /usr/lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/coroutine:242
(inlined by) seastar::internal::coroutine_traits_base<std::vector<dht::token_range_endpoints, std::allocator<dht::token_range_endpoints> > >::promise_type::run_and_dispose() at ././seastar/include/seastar/core/coroutine.hh:80
seastar::reactor::do_run() at ./build/release/seastar/./build/release/seastar/./seastar/src/core/reactor.cc:2635
std::_Function_handler<void (), seastar::smp::configure(seastar::smp_options const&, seastar::reactor_options const&)::$_0>::_M_invoke(std::_Any_data const&) at ./build/release/seastar/./build/release/seastar/./seastar/src/core/reactor.cc:4684
```
Fix by using chunked_vector.
Fixes#24158Closesscylladb/scylladb#24561
Currently, CI uses several nodes to execute the different modes to
reduce overall time for execution. During copying the results from nodes
to the main job test reports will be overwritten, since they are using
the same directory and the same name. This patch allows to
distinguishing these results and not overwrite them.
Closesscylladb/scylladb#24559
It just std::move-s a buffer and a semaphore_units objects, both moves
are noexcept, so is the constructor itself.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#24552
In f96d30c2b5
we introduced the maintenance service, which is an additional
instance of auth::service. But this service has a somewhat
confusing 2-level startup mechanism: it's initialized with
sharded<Service>::start and then auth::service::start
(different method with the same name to confuse even more).
When maintenance_socket was disabled (default setting), the code
did only the first part of the startup. This registered a config
observer but didn't create a permission_cache instance.
As a result, a crash on SIGHUP when config is reloaded can occur.
Fixes: https://github.com/scylladb/scylladb/issues/24528
Backport: all not eol versions since 6.0 and 2025.1
Closesscylladb/scylladb#24527
* github.com:scylladb/scylladb:
test: add test for live updates of permissions cache config
main: don't start maintenance auth service if not enabled
In f96d30c2b5
we introduced the maintenance service, which is an additional
instance of auth::service. But this service has a somewhat
confusing 2-level startup mechanism: it's initialized with
sharded<Service>::start and then auth::service::start
(different method with the same name to confuse even more).
When maintenance_socket was disabled (default setting), the code
did only the first part of the startup. This registered a config
observer but didn't create a permission_cache instance.
As a result, a crash on SIGHUP when config is reloaded can occur.
This PR adds an upgrade test for SSTable compression with shared dictionaries, and adds some bits to pylib and test.py to support that.
In the series, we:
1. Mount `$XDG_CACHE_DIR` into dbuild.
2. Add a pylib function which downloads and installs a released ScyllaDB package into a subdirectory of `$XDG_CACHE_DIR/scylladb/test.py`, and returns the path to `bin/scylla`.
3. Add new methods and params to the cluster manager, which let the test start nodes with historical Scylla executables, and switch executables during the test.
4. Add a test which uses the above to run an upgrade test between the released package and the current build.
5. Add `--run-internet-dependent-tests` to `test.py` which lets the user of `test.py` skip this test (and potentially other internet-dependent tests in the future).
(The patch modifying `wait_for_cql_and_get_hosts` is a part of the new test — the new test needs it to test how particular nodes in a mixed-version cluster react to some CQL queries.)
This is a follow-up to #23025, split into a separate PR because the potential addition of upgrade tests to `test.py` deserved a separate thread.
Needs backport to 2025.2, because that's where the tested feature is introduced.
Fixes#24110Closesscylladb/scylladb#23538
* github.com:scylladb/scylladb:
test: add test_sstable_compression_dictionaries_upgrade.py
test.py: add --run-internet-dependent-tests
pylib/manager_client: add server_switch_executable
test/pylib: in add_server, give a way to specify the executable and version-specific config
pylib: pass scylla_env environment variables to the topology suite
test/pylib: add get_scylla_2025_1_executable()
pylib/scylla_cluster: give a way to pass executable-specific options to nodes
dbuild: mount "$XDG_CACHE_HOME/scylladb"
In libstdc++15, the internal structure of an unordered container
hashtable node changed from _M_storage._M_storage.__data to just
_M_storage._M_storage (though the layout is the same). Adjust
the code to work with both variants.
Closesscylladb/scylladb#24549
The contract in mutation_reader.hh says:
```
// pr needs to be valid until the reader is destroyed or fast_forward_to()
// is called again.
future<> fast_forward_to(const dht::partition_range& pr) {
```
`test_fast_forwarding_combined_reader_is_consistent_with_slicing` violates
this by passing a temporary to `fast_forward_to`.
Fix that.
Fixesscylladb/scylladb#24542Closesscylladb/scylladb#24543
This patch intends to give an overview of where, when and how we store
data in S3 and provide a quick set of commands
which help gain local access to the data in case there is a need for
manual intervention.
The patch also collects in the same place links/descriptions for all
formats we use in S3.
Fixes#22438
Signed-off-by: Robert Bindar <robert.bindar@scylladb.com>
Closesscylladb/scylladb#24323
Revamped the `range` class to actively manage its state by enforcing validation on all modifications. This prevents overflow, invalid states, and ensures the object size does not exceed the 5TiB limit in S3. This should address and prevent future problems related to this issue https://github.com/minio/minio/issues/21333
No backport needed since this problem related only to this change https://github.com/scylladb/scylladb/pull/23880Closesscylladb/scylladb#24312
* github.com:scylladb/scylladb:
s3_client: headers cleanup
s3_client: Refactor `range` class for state validation
Refs #24447
Patch adding this somehow managed to leave out the thread_local
specifier. While gnutls cert object can be shared across shards
just fine, the actual shared_ptr here cannot, thus we could
cause memory errors.
Closesscylladb/scylladb#24514
This reverts commit 0b516da95b, reversing
changes made to 30199552ac. It breaks
cluster.random_failures.test_random_failures.test_random_failures
in debug mode (at least).
Fixes#24513
Revamped the `range` class to actively manage its state by enforcing validation on all modifications. This prevents overflow, invalid states, and ensures the object size does not exceed the 5TiB limit in S3.
With current changes, pytest executes boost tests. Gathering metrics added to the pytest BoostFacade and UnitFacade to have the possibility to get them for C++ test as previously.
Since boost, raft, unit, and ldap directories aren't executed by test.py, suite.yaml files are renamed to test_config.yaml to preserve the old way of test configuration and removing them from execution by test.py
Pytest executes all modes by itself, JUnit report for the C++ test will be one for the run. That means that there is no possibility to output them in testlog in different folders. So testlog/report directory is used to store all kinds of reports generated during tests. JUnit reports should be testlog/report/junit, Allure reports should be in testlog/report/allure.
**Breaking changes:**
1. Terminal output changed. test.py will run pytest for the next directories: `test/boost`, `test/ldap`, `test/raft`, `test/unit`. `test.py` will blindly translate the output of the pytest to the terminal. Then when all these tests are finished, `test.py` will continue to show previous output for the rest of the test.
2. The format of execution of C++ test directories mentioned above has been changed. Now it will be a simple path to the file with extension. For example, instead of `boost/aggregate_fcts_test` now you need to use `test/boost/aggregate_fcts_test.cc`
3. This PR creates a spike in test amount. The previous logic was to consolidate the boost results from different runs and different modes to one report. So for the three repeats and three modes (nine test results) in CI was shown one result. Now it shows nine results, with differentiating them by mode and run.
**Note:**
Pytest uses pytest-xdist module to run tests in parallel. The Frozen toolchain has this dependency installed, for the local use, please install it manually.
Changes for CI https://github.com/scylladb/scylla-pkg/pull/4949. It will be merged after the current PR will be in master. Short disruption is expected, while PR in scylla-pkg will not be merged.
Fixes: https://github.com/scylladb/qa-tasks/issues/1777Closesscylladb/scylladb#22894
* github.com:scylladb/scylladb:
test.py: clean code that isn't used anymore
test.py: switch off C++ tests from test.py discovery
test.py: Integrate pytest c++ test execution to test.py
The one collects map<ip, state> then converts it to a jsonable vector of
helper objects with key and value members. This patch removes the
intermediate map and creates the vector instantly. With that change the
handler makes less data manipulations and behaves like the
get_all_endpoint_states one.
Very similar change was done in 12420dc644 with get_host_to_id_map
handler.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#24456
Our documentation docs/alternator/new-apis.md claims that Alternator TTL
does not work with tablets, due to issue #16567. However, we fixed that
issue in commit de96c28625. So let's drop
the outdated statement that it doesn't work.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#24427
Revise how we report statistics for `chunked_download_source`. Ensure
metrics for downloaded but unconsumed data are visible, as they do not
contribute to read amplification, which is tracked separately.
Closesscylladb/scylladb#24491
Applier fiber needs local storage, so before shutting down local storage we need to make sure that group0 is stopped.
We also improve the logs for the case when `gate_closed_exception` is thrown while a mutation is being written.
Fixes [scylladb/scylladb#24401](https://github.com/scylladb/scylladb/issues/24401)
Backport: no backport -- not safe and the problem is minor.
Closesscylladb/scylladb#24418
* github.com:scylladb/scylladb:
storage_service: test_group0_apply_while_node_is_being_shutdown
main.cc: fix group0 shutdown order
storage_proxy: log gate_closed_exception
This patch updates alternator/stats.cc and the get_description.py
configuration (metrics-config.yml) to restore compatibility with
per-table alternator metrics in the documentation generation process.
Previously, the group name for metrics was selected using an inline
expression like (has_table)? "alternator_table" : "alternator", which
made it difficult to maintain a straightforward mapping in the
configuration file. With this change, the group name is now assigned to
a variable in alternator/stats.cc, allowing metrics-config.yml to map
group names directly. This makes the configuration easier to maintain
and enables get_description.py to document both global and per-table
metrics correctly.
This is a minimal, targeted fix to get the documentation working again
with the new per-table metrics format.
Signed-off-by: Amnon Heiman <amnon@scylladb.com>
Closesscylladb/scylladb#24509
An interval object stores five booleans: start()->is_inclusive(),
a boolean since start() itself is an std::optional, two more for
end(), and is_singular(). Due to bad packing, these five booleans
occupy 8 bytes each, for a total of 40 bytes.
Re-pack the interval class by storing those booleans explicitly
close by. Since we lose std::optional's ability to store
a maybe-constructed object, we re-implement it using anonymous
unions and therefore have to implement the 5 special methods.
This helps saves space when vectors of intervals are used, as
seen in #3335 for example.
We'd like to change the data layout of `interval` to save space.
As a result, start() and end() which return references to data
members must return objects (not references). Since we'd like
to maintain zero-copy for these functions, we change them to
return objects containing references (rather than references
to objects), avoiding copying of potentially expensive objects.
We repurpose the interval_bound class to hold references (by
instantiating it with `const T&` instead of `T`) and provide
converting constructors. To make transform_bounds() retain
zero-copy, we add start() and end() that take *this by
rvalue reference.
We are about to change start() to return a proxy object rather
than a `const interval_bound<T>&`. This is generally transparent,
except in one case: `auto x = i.start()`. With the current implementation,
we'll copy object referred to and assign it to x. With the planned
implementation, the proxy object will be assigned to `x`, but it
will keep referring to `i`.
To prevent such problems, rename start() to start_ref() and end()
to end_ref(). This forces us to audit all calls, and redirect calls
that will break to new start_copy() and end_copy() methods.
In this series, we will make interval manage its memory directly,
specifically it will directly construct and destroy T values that
it contains rather than let std::optional<T> manage those values
itself.
Add tests that expose bugs encountered during development (actually,
review) of this series. The tests pass before the series, fail
with series as it was before fixing, and pass with the series as
it is now.
The tests use a class maybe_throwing_interval_payload that can
be set to throw at strategic locations and exercise all the interesting
interval shapes.
Refactor the voter handler logic to only pass around node IDs (`raft::server_id`), instead of pairs of IDs and node descriptor references. Node descriptors can always be efficiently retrieved from the original nodes map, which remains valid throughout the calculation.
This change reduces unnecessary reference passing and simplifies the code. All node detail lookups are now performed via the central nodes map as needed.
Additional cleanup has been done:
* removing redundant comments (that just repeat what the code does)
* use explicit comparators for the datacenter and rack information priorities (instead of the comparison operator) to be more explicit about the prioritization
Fixes: scylladb/scylladb#24035
No backport: This change does not fix any bug and doesn't change the behavior, just cleans up the code in master, therefore no backport is needed.
Closesscylladb/scylladb#24452
* https://github.com/scylladb/scylladb:
raft: simplify voter handler code to not pass node references around
raft: reformat voter handler for consistent indentation
raft: use explicit priority comparators for datacenters and racks
raft: clean up voter handler by removing redundant comments
Copied the entire audit_test.py from scylladb/scylla-dtest, to remove the entire file from scylla-dtest after this patch series is merged. The motivation is to move entire audit testing to from dtests, to make it easier to maintain and more reliable.
After audit_test.py was moved from dtests to test.py, some issues that require fixing arose due to differences between the frameworks.
No backport, moving audit_test.py to test.py is a new testing effort.
Closesscylladb/scylladb#24231
* github.com:scylladb/scylladb:
test: audit: filter out LOGIN and USE audit logs
test: audit: remove require mark
test: audit: wait until raft state is applied in test_permissions
test: audit: fix problems in audit_test.py
test: dtest: add dict support to populate in scylla_cluster.py
test: dtest: copied get_node_ip from dtests to scylla_cluster.py
test: dtest: copy run_rest_api from dtests to cluster.py
test: dtest: copy run_in_parallel from dtests to data.py
test: audit: copy unmodified audit_test.py from dtests
Switch off C++ tests from test.py discovery. With this change, test.py loses
the ability to directly see and run the C++ tests. Instead, it'll delegate all
things to the pytest.
Since boost, raft, unit, and ldap directories aren't executed by test.py,
suite.yaml files are renamed to test_config.yaml
to preserve the old way of test configuration and removing them from execution
by test.py
Before this patch boost test were visible by test.py and pytest. So if the
test.py will be invoked without test name, it will execute boost tests twice:
with test.py executor and with pytest executor. Depending on the test name
according executor will be used. For example, if test name is
test/boost/aggregate_fcts_test.cc it will be executed by pytest, but if the
boost/aggregate_fcts_test it will be executed by test.py executor.
With current changes pytest executes boost tests. Gathering metrics added to the pytest BoostFacade and UnitFacade
to have the possibility to get them for C++ test as previously.
Since pytest executes all modes by itself JUnit report for the C++ test will be one for the run. That means that there
is no possibility to output them in testlog in different folders. So testlog/report directory is used to store all kinds
of reports generated during tests. JUnit reports should be testlog/report/junit, Allure reports should be in
testlog/report/allure.
**Breaking changes: **
1. Terminal output changed. test.py will run pytest for next directories: test/boost, test/ldap, test/raft, test/unit.
test.py will blindly translate the output of the pytest to the terminal. Then when all these tests are finished, test.py
will continue to show previous output for the rest of the test.
2. The format of execution of C++ test directories mentioned above has been changed. Now it will be a simple path to the
file with extension. For example, instead of boost/aggregate_fcts_test now you need to use test/boost/aggregate_fcts_test.cc
3. This PR creates a spike in test amount. The previous logic was to consolidate the boost results from different runs
and different modes to one report. So for the three repeats and three modes (nine test results) in CI was shown one result.
Now it shows nine results with differentiating them by mode and run.
Note:
Pytest uses pytest-xdist module to run tests in parallel. Frozen toolchain has this dependency installed, for the local
use, please install it manually.
When a tablet is migrated and cleaned up, deallocate the tablet storage
group state on `end_migration` stage, instead of `cleanup` stage:
* When the stage is updated from `cleanup` to `end_migration`, the
storage group is removed on the leaving replica.
* When the table is initialized, if the tablet stage is `end_migration`
then we don't allocate a storage group for it. This happens for
example if the leaving replica is restarted during tablet migration.
If it's initialized in `cleanup` stage then we allocate a storage
group, and it will be deallocated when transitioning to
`end_migration`.
This guarantees that the storage group is always deallocated on the
leaving replica by `end_migration`, and that it is always allocated if
the tablet wasn't cleaned up fully yet.
It is a similar case also for the pending replica when the migration is
aborted. We deallocate the state on `revert_migration` which is the
stage following `cleanup_target`.
Previously the storage group would be allocated when the tablet is
initialized on any of the tablet replicas - also on the leaving replica,
and when the tablet stage is `cleanup` or `end_migration`, and
deallocated during `cleanup`.
This fixes the following issue:
1. A migrating tablet enters cleanup stage
2. the tablet is cleaned up successfuly
3. The leaving replica is restarted, and allocates storage group
4. tablet cleanup is not called because it's already cleaned up
5. the storage group remains allocated on the leaving replica after the
migration is completed - it's not cleaned up properly.
Fixes https://github.com/scylladb/scylladb/issues/23481
backport to all relevant releases since it's a bug that results in a crash
Closesscylladb/scylladb#24393
* github.com:scylladb/scylladb:
test/cluster/test_tablets: test restart during tablet cleanup
test: tablets: add get_tablet_info helper
tablets: deallocate storage state on end_migration
LOGIN entries can appear at many points during testing, for example,
when a driver creates a new session. Similarly, `USE ks` statements
can appear unexpectedly, especially when the python-driver calls
`set_keyspace_async` for new connections.
To avoid test checks failures,
this commit filters out LOGIN and USE entries in tests that are
not intended to verify these two types of audit logs.
After audit_test.py was moved from dtests to test.py, the
following issues arose due to differences between the frameworks:
- Some imports were unnecessary or broken
- The @pytest.mark.dtest_full decorator was no longer needed
- The `issue_open` attribute in `xmark` is not supported
- Support for sending SIGHUP is encapsulated
by `server_update_config` in test.py`
- A workaround for scylladb#24473 was required
Moreover, suite.yaml was changed to start running audit_test.py
in dev mode.
Ref. scylladb#24473
Co-authored-by: Marcin Maliszkiewicz <marcinmal@scylladb.com>
It has been observed to generate ~200 kiB allocations.
Since we have already been made aware of that, we can silence the warning
to clean up the logs.
Closesscylladb/scylladb#24360
group0 persistence relies on local storage, so before
shutting down local storage we need to make sure that
group0 is stopped.
Fixesscylladb/scylladb#24401
Add system:table_creation_time tag with value - timestamp in milliseconds of creation table.
If the tag is present, it will used to fill creation timestamp value (when CreateTable or DescribeTable is called).
If the tag is missing, value 0 for timestamp will be substituted (in other words table was created on 1th january of 1970).
Update test to change how we make sure timestamp is actually used - we create two tables one after another and make sure their creation timestamp is in correct order.
Update tests, that work with tags to filter system tags out.
Fixes#5013Closesscylladb/scylladb#24007
This patch adds a couple of basic tests for system tables related to
secondary indexes - system."IndexInfo" and system_schema.indexes.
I wanted to understand these system tables better when writing
documentation for them - so wrote these tests. These tests can also
serve as regression tests that verify that we don't accidentally lose
support for these system tables. I checked that these tests also pass
in Cassandra 3, 4 and 5.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#24137
This change is preparing ground for state update unification for raft bound subsystems. It introduces schema_applier which in the future will become generic interface for applying mutations in raft.
Pulling `database::apply()` out of schema merging code will allow to batch changes to subsystems. Future generic code will first call `prepare()` on all implementations, then single `database::apply()` and then `update()` on all implementations, then on each shard it will call `commit()` for all implementations, without preemption so that the change is observed as atomic across all subsystems, and then `post_commit()`.
Backport: no, it's a new feature
Fixes: https://github.com/scylladb/scylladb/issues/19649Closesscylladb/scylladb#20853
* github.com:scylladb/scylladb:
storage_service: always wake up load balancer on update tablet metadata
db: schema_applier: call destroy also when exception occurs
db: replica: simplify seeding ERM during shema change
db: remove cleanup from add_column_family
db: abort on exception during schema commit phase
db: make user defined types changes atomic
replica: db: make keyspace schema changes atomic
db: atomically apply changes to tables and views
replica: make truncate_table_on_all_shards get whole schema from table_shards
service: split update_tablet_metadata into two phases
service: pull out update_tablet_metadata from migration_listener
db: service: add store_service dependency to schema_applier
service: simplify load_tablet_metadata and update_tablet_metadata
db: don't perform move on tablet_hint reference
replica: split add_column_family_and_make_directory into steps
replica: db: split drop_table into steps
db: don't move map references in merge_tables_and_views()
db: introduce commit_on_shard function
db: access types during schema merge via special storage
replica: make non-preemptive keyspace create/update/delete functions public
replica: split update keyspace into two phases
replica: split creating keyspace into two functions
db: rename create_keyspace_from_schema_partition
db: decouple functions and aggregates schema change notification from merging code
db: store functions and aggregates change batch in schema_applier
db: decouple tables and views schema change notifications from merging code
db: store tables and views schema diff in schema_applier
db: decouple user type schema change notifications from types merging code
service: unify keyspace notification functions arguments
db: replica: decouple keyspace schema change notifications to a separate function
db: add class encapsulating schema merging
The existing `download_source` implementation optimizes performance
by keeping the connection to S3 open and draining data directly from
the socket. While this eliminates the overhead (60-100ms) of repeatedly
establishing new connections, it leads to rapid exhaustion of client-
side connections.
On a single shard, two `mx_readers` for load and stream are enough to
trigger this issue. Since each client typically holds two connections,
readers keeping index and data sources open can cause deadlocks where
processes stall due to unavailable connections.
Introduce `chunked_download_source`, a new S3 download method built on
`download_source`, to dynamically manage connections:
- Buffers data in 5MiB chunks using a producer-consumer model
- Closes connections once buffers reach capacity, returning them to
the pool for other clients
- Uses a filling fiber that resumes fetching once buffers are
consumed from the queue
Performance remains comparable to `download_source`, achieving
95MiB/s for sequential 1GiB downloads from S3. However, preloading
large chunks may cause read amplification.
Fixes: https://github.com/scylladb/scylladb/issues/23785Closesscylladb/scylladb#23880
