before this change, we rely on the default-generated fmt::formatter
created from operator<<, but fmt v10 dropped the default-generated
formatter.
in this change, we include `fmt/ranges.h` and/or `fmt/std.h`
for formatting the container types, like vector, map
optional and variant using {fmt} instead of the homebrew
formatter based on operator<<.
with this change, the changes adding fmt::formatter and
the changes using ostream formatter explicitly, we are
allowed to drop `FMT_DEPRECATED_OSTREAM` macro.
Refs scylladb#13245
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
In test_exception_safety_of_update_from_memtable, we have a potential
throw from external_updater.
external_updater is supposed to be infallible.
Scylla currently aborts when an external_updater throws, so a throw from
there just fails the test.
This isn't intended. We aren't testing external_updater in this test.
Fixes#18163Closesscylladb/scylladb#18171
Calling `_next_row.get_iterator_in_latest()` is illegal when `_next_row` is not
pointing at a row. In particular, the iterator returned by such call might be
dangling.
We have observed this to cause a use-after-free in the field, when a reverse
read called `maybe_add_to_cache` after `_latest_it` was left dangling after
a dead row removal in `copy_from_cache_to_buffer`.
To fix this, we should ensure that we only call `_next_row.get_iterator_in_latest`
is pointing at a row.
Only the occurrences of this problem in `maybe_add_to_cache` are truly dangerous.
As far as I can see, other occurrences can't break anything as of now.
But we apply fixes to them anyway.
Closesscylladb/scylladb#18046
get0() dates back from the days where Seastar futures carried tuples, and
get0() was a way to get the first (and usually only) element. Now
it's a distraction, and Seastar is likely to deprecate and remove it.
Replace with seastar::future::get(), which does the same thing.
Store schema_ptr in reader permit instead of storing a const pointer to
schema to ensure that the schema doesn't get changed elsewhere when the
permit is holding on to it. Also update the constructors and all the
relevant callers to pass down schema_ptr instead of a raw pointer.
Fixes#16180
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
Closesscylladb/scylladb#16658
To be used in the next patch to control whether the semaphore registers
and exports metrics or not. We want to move metric registration to the
semaphore but we don't want all semaphores to export metrics. The
decision on whether a semaphore should or shouldn't export metrics
should be made on a case-by-case basis so this new parameter has no
default value (except for the for_tests constructor).
There's one in the utils that creates lw_shared_ptr<memtable> and
applies provided vector of mutations into it. Lots of other test cases
do literally the same by hand.
The make_memtable() assumes that the caller is sitting in the seastar
thread, and all the test cases that can benfit from it already are.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Consider the following code snippet:
```c++
future<> foo() {
semaphore.consume(1024);
}
future<> bar() {
return _allocating_section([&] {
foo();
});
}
```
If the consumed memory triggers the OOM kill limit, the semaphore will throw `std::bad_alloc`. The allocating section will catch this, bump std reserves and retry the lambda. Bumping the reserves will not do anything to prevent the next call to `consume()` from triggering the kill limit. So this cycle will repeat until std reserves are so large that ensuring the reserve fails. At this point LSA gives up and re-throws the `std::bad_alloc`. Beyond the useless time spent on code that is doomed to fail, this also results in expensive LSA compaction and eviction of the cache (while trying to ensure reserves).
Prevent this situation by throwing a distinct exception type which is derived from `std::bad_alloc`. Allocating section will not retry on seeing this exception.
A test reproducing the bug is also added.
Fixes: #15278Closesscylladb/scylladb#15581
* github.com:scylladb/scylladb:
test/boost/row_cache_test: add test_cache_reader_semaphore_oom_kill
utils/logalloc: handle utils::memory_limit_reached in with_reclaiming_disabled()
reader_concurrency_semaphore: use utils::memory_limit_reached exception
utils: add memory_limit_reached exception
The test does (among other things) the following:
1. Create a cache reader with buffer of size 1 and fill the buffer.
2. Update the cache.
3. Check that the reader produces the first mutation as seen before
the update (because the buffer fill should have snapshotted the first
mutation), and produces other mutation as seen after the update.
However, the test is not guaranteed to stop after the update succeeds.
Even during a successful update, an allocation might have failed
(and been retried by an allocation_section), which will cause the
body of with_allocation_failures to run again. On subsequent runs
the last check (the "3." above) fails, because the first mutation
is snapshotted already with the new version.
Fix that.
Closesscylladb/scylladb#15634
Check that the cache reader reacts correctly to semaphore's OOM kill
attempt, letting the read to fail, instead of going berserk, trying to
reserve more-and-more memory, until the reserve cannot be satisfied.
Same as in previous patch, the cql_test_env::require_table_exists()
helper is exactly the same, but returns future and asserts on failures
for no gain
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
In the next commit, we remove the default value for the
description parameter of migration_manager::announce to avoid
using it in the future. However, many calls to announce in tests
use the default value. We have to change it, but we don't really
care about descriptions in the tests, so we pass the empty string
everywhere.
The migration_manager service is responsible for schema convergence
in the cluster - pushing schema changes to other nodes and pulling
schema when a version mismatch is observed. However, there is also
a part of migration_manager that doesn't really belong there -
creating mutations for schema updates. These are the functions with
prepare_ prefix. They don't modify any state and don't exchange any
messages. They only need to read the local database.
We take these functions out of migration_manager and make them
separate functions to reduce the dependency of other modules
(especially query_processor and CQL statements) on
migration_manager. Since all of these functions only need access
to storage_proxy (or even only replica::database), doing such a
refactor is not complicated. We just have to add one parameter,
either storage_proxy or database and both of them are easily
accessible in the places where these functions are called.
test.py with --x-log2-compaction-groups option rotted a little bit.
Some boost tests added later didn't use the correct header which
parses the option or they didn't adjust suite.yaml.
Perhaps it's time to set up a weekly (or bi-weekly) job to verify
there are no regressions with it. It's important as it stresses
the data plane for tablets reusing the existing tests available.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#14732
when read from cache compact and expire row tombstones
remove expired empty rows from cache
do not expire range tombstones in this patch
Refs #2252, #6033Closes#12917
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
After a schema change, memtable and cache have to be upgraded to the new schema. Currently, they are upgraded (on the first access after a schema change) atomically, i.e. all rows of the entry are upgraded with one non-preemptible call. This is a one of the last vestiges of the times when partition were treated atomically, and it is a well known source of numerous large stalls.
This series makes schema upgrades gentle (preemptible). This is done by co-opting the existing MVCC machinery.
Before the series, all partition_versions in the partition_entry chain have the same schema, and an entry upgrade replaces the entire chain with a single squashed and upgraded version.
After the series, each partition_version has its own schema. A partition entry upgrade happens simply by adding an empty version with the new schema to the head of the chain. Row entries are upgraded to the current schema on-the-fly by the cursor during reads, and by the MVCC version merge ongoing in the background after the upgrade.
The series:
1. Does some code cleanup in the mutation_partition area.
2. Adds a schema field to partition_version and removes it from its containers (partition_snapshot, cache_entry, memtable_entry).
3. Adds upgrading variants of constructors and apply() for `row` and its wrappers.
4. Prepares partition_snapshot_row_cursor, mutation_partition_v2::apply_monotonically and partition_snapshot::merge_partition_versions for dealing with heterogeneous version chains.
5. Modifies partition_entry::upgrade to perform upgrades by extending the version chain with a new schema instead of squashing it to a single upgraded version.
Fixes#2577Closes#13761
* github.com:scylladb/scylladb:
test: mvcc_test: add a test for gentle schema upgrades
partition_version: make partition_entry::upgrade() gentle
partition_version: handle multi-schema snapshots in merge_partition_versions
mutation_partition_v2: handle schema upgrades in apply_monotonically()
partition_version: remove the unused "from" argument in partition_entry::upgrade()
row_cache_test: prepare test_eviction_after_schema_change for gentle schema upgrades
partition_version: handle multi-schema entries in partition_entry::squashed
partition_snapshot_row_cursor: handle multi-schema snapshots
partiton_version: prepare partition_snapshot::squashed() for multi-schema snapshots
partition_version: prepare partition_snapshot::static_row() for multi-schema snapshots
partition_version: add a logalloc::region argument to partition_entry::upgrade()
memtable: propagate the region to memtable_entry::upgrade_schema()
mutation_partition: add an upgrading variant of lazy_row::apply()
mutation_partition: add an upgrading variant of rows_entry::rows_entry
mutation_partition: switch an apply() call to apply_monotonically()
mutation_partition: add an upgrading variant of rows_entry::apply_monotonically()
mutation_fragment: add an upgrading variant of clustering_row::apply()
mutation_partition: add an upgrading variant of row::row
partition_version: remove _schema from partition_entry::operator<<
partition_version: remove the schema argument from partition_entry::read()
memtable: remove _schema from memtable_entry
row_cache: remove _schema from cache_entry
partition_version: remove the _schema field from partition_snapshot
partition_version: add a _schema field to partition_version
mutation_partition: change schema_ptr to schema& in mutation_partition::difference
mutation_partition: change schema_ptr to schema& in mutation_partition constructor
mutation_partition_v2: change schema_ptr to schema& in mutation_partition_v2 constructor
mutation_partition: add upgrading variants of row::apply()
partition_version: update the comment to apply_to_incomplete()
mutation_partition_v2: clean up variants of apply()
mutation_partition: remove apply_weak()
mutation_partition_v2: remove a misleading comment in apply_monotonically()
row_cache_test: add schema changes to test_concurrent_reads_and_eviction
mutation_partition: fix mixed-schema apply()
As described in https://github.com/scylladb/scylladb/issues/8638,
we're moving away from `SimpleStrategy`, in the future
it will become deprecated.
We should remove all uses of it and replace them
with `NetworkTopologyStrategy`.
This change replaces `SimpleStrategy` with
`NetworkTopologyStrategy` in all unit tests,
or at least in the ones where it was reasonable to do so.
Some of the tests were written explicitly to test the
`SimpleStrategy` strategy, or changing the keyspace from
`SimpleStrategy` to `NetworkTopologyStrategy`.
These tests were left intact.
It's still a feature that is supported,
even if it's slowly getting deprecated.
The typical way to use `NetworkTopologyStrategy` is
to specify a replication factor for each datacenter.
This could be a bit cumbersome, we would have to fetch
the list of datacenters, set the repfactors, etc.
Luckily there is another way - we can just specify
a replication factor to use for or each existing
datacenter, like this:
```cql
CREATE KEYSPACE {} WITH REPLICATION =
{'class' : 'NetworkTopologyStrategy', 'replication_factor' : 1};
```
This makes the change rather straightforward - just replace all
instances of `'SimpleStrategy'', with `'NetworkTopologyStrategy'`.
Refs: https://github.com/scylladb/scylladb/issues/8638
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
Closes#13990
The upcoming schema upgrade change will perform the schema upgrade by adding
a new version (with the new schema) to the partition entry.
To clean a multi-version entry, eviction is not enough - the versions have
to be merged and/or cleared first. drain() does just that.
No point in going through the vector<mutation> entry-point
just to discover in run time that it was called
with a single-element vector, when we know that
in advance.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Closes#13733
Adds a reproducer for #12462, which doesn't manifest in master any
more after f73e2c992f. It's still useful
to keep the test to avoid regresions.
The bug manifests by reader throwing:
std::logic_error: Stream ends with an active range tombstone: {range_tombstone_change: pos={position: clustered,ckp{},-1}, {tombstone: timestamp=-9223372036854775805, deletion_time=2}}
The reason is that prior to the rework of the cache reader,
range_tombstone_generator::flush() was used with end_of_range=true to
produce the closing range_tombstone_change and it did not handle
correctly the case when there are two adjacent range tombstones and
flush(pos, end_of_range=true) is called such that pos is the boundary
between the two.
Closes#13665
now that fmtlib provides fmt::join(). see
https://fmt.dev/latest/api.html#_CPPv4I0EN3fmt4joinE9join_viewIN6detail10iterator_tI5RangeEEN6detail10sentinel_tI5RangeEEERR5Range11string_view
there is not need to revent the wheel. so in this change, the homebrew
join() is replaced with fmt::join().
as fmt::join() returns an join_view(), this could improve the
performance under certain circumstances where the fully materialized
string is not needed.
please note, the goal of this change is to use fmt::join(), and this
change does not intend to improve the performance of existing
implementation based on "operator<<" unless the new implementation is
much more complicated. we will address the unnecessarily materialized
strings in a follow-up commit.
some noteworthy things related to this change:
* unlike the existing `join()`, `fmt::join()` returns a view. so we
have to materialize the view if what we expect is a `sstring`
* `fmt::format()` does not accept a view, so we cannot pass the
return value of `fmt::join()` to `fmt::format()`
* fmtlib does not format a typed pointer, i.e., it does not format,
for instance, a `const std::string*`. but operator<<() always print
a typed pointer. so if we want to format a typed pointer, we either
need to cast the pointer to `void*` or use `fmt::ptr()`.
* fmtlib is not able to pick up the overload of
`operator<<(std::ostream& os, const column_definition* cd)`, so we
have to use a wrapper class of `maybe_column_definition` for printing
a pointer to `column_definition`. since the overload is only used
by the two overloads of
`statement_restrictions::add_single_column_parition_key_restriction()`,
the operator<< for `const column_definition*` is dropped.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
these warnings are found by Clang-17 after removing
`-Wno-unused-lambda-capture` and '-Wno-unused-variable' from
the list of disabled warnings in `configure.py`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.
Closes#12858
Move mutation-related files to a new mutation/ directory. The names
are kept in the global namespace to reduce churn; the names are
unambiguous in any case.
mutation_reader remains in the readers/ module.
mutation_partition_v2.cc was missing from CMakeLists.txt; it's added in this
patch.
This is a step forward towards librarization or modularization of the
source base.
Closes#12788
Merging rows from different partition versions should preserve the LRU link of
the entry from the newer version. We need this in case we're merging two last
dummy entries where the older dummy is already unlinked from the LRU. The
newer dummy could be the last entry which is still holding the partition
entry linked in the LRU.
The mutation_partition_v2 merging didn't take the LRU link from the newer
entry, and we could end up with the partition entry not having any entries
linked in the LRU.
Introduced in f73e2c992f.
Fixes#12778Closes#12785
We currently have two method families to generate partition keys:
* make_keys() in test/lib/simple_schema.hh
* token_generation_for_shard() in test/lib/sstable_utils.hh
Both work only for schemas with a single partition key column of `text` type and both generate keys of fixed size.
This is very restrictive and simplistic. Tests, which wanted anything more complicated than that had to rely on open-coded key generation.
Also, many tests started to rely on the simplistic nature of these keys, in particular two tests started failing because the new key generation method generated keys of varying size:
* sstable_compaction_test.sstable_run_based_compaction_test
* sstable_mutation_test.test_key_count_estimation
These two tests seems to depend on generated keys all being of the same size. This makes some sense in the case of the key count estimation test, but makes no sense at all to me in the case of the sstable run test.
Closes#12657
* github.com:scylladb/scylladb:
test/lib/sstable_utils: remove now unused token_generation_for_shard() and friends
test/lib/simple_schema: remove now unused make_keys() and friends
test: migrate to tests::generate_partition_key[s]()
test/lib/test_services: add table_for_tests::make_default_schema()
test/lib: add key_utils.hh
test/lib/random_schema.hh: value_generator: add min_size_in_bytes
Use the newly introduced key generation facilities, instead of the the
old inflexible alternatives and hand-rolled code.
Most of the migrations are mechanic, but there are two tests that
were tricky to migrate:
* sstable_compaction_test.sstable_run_based_compaction_test
* sstable_mutation_test.test_key_count_estimation
These two tests seems to depend on generated keys all being of the same
size. This makes some sense in the case of the key count estimation
test, but makes no sense at all to me in the case of the sstable run
test.
This patch switches memtable and cache to use mutation_partition_v2,
and all affected algorithms accordingly.
The memtable reader was changed to use the same cursor implementation
which cache uses, for improved code reuse and reducing risk of bugs
due to discrepancy of algorithms which deal with MVCC.
Range tombstone eviction in cache has now fine granularity, like with
rows.
Fixes#2578Fixes#3288Fixes#10587
change row purge condition for compacting_reader to remove all expired
rows to avoid read perfomance problems when there are many expired
tombstones in row cache
Refs #2252Closes#12565
Regression introduced in 23e4c8315.
view_and_holder position_in_partiton::after_key() triggers undefined
behavior when the key was not full because the holder is moved, which invalidates the view.
Fixes#12367Closes#12447
Consider the following MVCC state of a partition:
v2: ==== <7> [entry2] ==== <9> ===== <last dummy>
v1: ================================ <last dummy> [entry1]
Where === means a continuous range and --- means a discontinuous range.
After two LRU items are evicted (entry1 and entry2), we will end up with:
v2: ---------------------- <9> ===== <last dummy>
v1: ================================ <last dummy> [entry1]
This will cause readers to incorrectly think there are no rows before
entry <9>, because the range is continuous in v1, and continuity of a
snapshot is a union of continuous intervals in all versions. The
cursor will see the interval before <9> as continuous and the reader
will produce no rows.
This is only temporary, because current MVCC merging rules are such
that the flag on the latest entry wins, so we'll end up with this once
v1 is no longer needed:
v2: ---------------------- <9> ===== <last dummy>
...and the reader will go to sstables to fetch the evicted rows before
entry <9>, as expected.
The bug is in rows_entry::on_evicted(), which treats the last dummy
entry in a special way, and doesn't evict it, and doesn't clear the
continuity by omission.
The situation is not easy to trigger because it requires certain
eviction pattern concurrent with multiple reads of the same partition
in different versions, so across memtable flushes.
Closes#12452
This fixes a long standing bug related to handling of non-full
clustering keys, issue #1446.
after_key() was creating a position which is after all keys prefixed
by a non-full key, rather than a position which is right after that
key.
This will issue will be caught by cql_query_test::test_compact_storage
in debug mode when mutation_partition_v2 merging starts inserting
sentinels at position after_key() on preemption.
It probably already causes problems for such keys.
Memtables and cache will compact eagerly, so tests should not expect
readers to produce exact mutations written, only those which are
equivalant after applying copmaction.
This reverts commit e0670f0bb5, reversing
changes made to 605ee74c39. It causes failures
in debug mode in
database_test.test_database_with_data_in_sstables_is_a_mutation_source_plain,
though with low probability.
Fixes#10780Reopens#652.
Memtables and cache will compact eagerly, so tests should not expect
readers to produce exact mutations written, only those which are
equivalant after applying copmaction.
