Secondary index creation is asynchronous, meaning it
takes time for existing data to be reflected within
the index. However, new data added after the
index is created should appear in it immediately.
The test consisted of two parts. The first created
a series of indexes for one table, added
test data to the table, and then ran a series of checks.
In the second part, several new indexes were added to
the same table, and checks were made to make sure that
already existing data would appear in them. This
last part was flaky.
The patch just moves the index creation statements
from the second part to the first.
Fixes: #14076Closes#14090
(cherry picked from commit 0415ac3d5f)
Closes#15101
The eps reference was reused to manipulate
the racks dictionary. This resulted in
assigning a set of nodes from the racks
dictionary to an element of the _dc_endpoints dictionary.
This is a backport of bcb1d7c to branch-5.2.
Refs: #14184Closes#14893
If semaphore mismatch occurs, check whether both semaphores belong
to user. If so, log a warning, log a `querier_cache_scheduling_group_mismatches` stat and drop cached reader instead of throwing an error.
Until now, semaphore mismatch was only checked in multi-partition queries. The PR pushes the check to `querier_cache` and perform it on all `lookup_*_querier` methods.
The mismatch can happen if user's scheduling group changed during
a query. We don't want to throw an error then, but drop and reset
cached reader.
This patch doesn't solve a problem with mismatched semaphores because of changes in service levels/scheduling groups but only mitigate it.
Refers: https://github.com/scylladb/scylla-enterprise/issues/3182
Refers: https://github.com/scylladb/scylla-enterprise/issues/3050Closes: #14770Closes#14736
* github.com:scylladb/scylladb:
querier_cache: add stats of scheduling group mismatches
querier_cache: check semaphore mismatch during querier lookup
querier_cache: add reference to `replica::database::is_user_semaphore()`
replica:database: add method to determine if semaphore is user one
(cherry picked from commit a8feb7428d)
Te view updating consumer uses `_buffer_size` to decide when to flush the accumulated mutations, passing them to the actual view building code. This `_buffer_size` is incremented every time a mutation fragment is consumed. This is not exact, as e.g. range tombstones are represented differently in the mutation object, than in the fragment, but it is good enough. There is one flaw however: `_buffer_size` is not incremented when consuming a partition-start fragment. This is when the mutation object is created in the mutation rebuilder. This is not a big problem when partition have many rows, but if the partitions are tiny, the error in accounting quickly becomes significant. If the partitions are empty, `_buffer_size` is not bumped at all for empty partitions, and any number of these can accumulate in the buffer. We have recently seen this causing stalls and OOM as the buffer got to immense size, only containing empty and tiny partitions.
This PR fixes this by accounting the size of the freshly created `mutation` object in `_buffer_size`, after the partition-start fragment is consumed.
Fixes: #14819Closes#14821
* github.com:scylladb/scylladb:
test/boost/view_build_test: add test_view_update_generator_buffering_with_empty_mutations
db/view/view_updating_consumer: account for the size of mutations
mutation/mutation_rebuilder*: return const mutation& from consume_new_partition()
mutation/mutation: add memory_usage()
(cherry picked from commit 056d04954c)
It was found that cached_file dtor can hit the following assert
after OOM
cached_file_test: utils/cached_file.hh:379: cached_file::~cached_file(): Assertion _cache.empty()' failed.`
cached_file's dtor iterates through all entries and evict those
that are linked to LRU, under the assumption that all unused
entries were linked to LRU.
That's partially correct. get_page_ptr() may fetch more than 1
page due to read ahead, but it will only call cached_page::share()
on the first page, the one that will be consumed now.
share() is responsible for automatically placing the page into
LRU once refcount drops to zero.
If the read is aborted midway, before cached_file has a chance
to hit the 2nd page (read ahead) in cache, it will remain there
with refcount 0 and unlinked to LRU, in hope that a subsequent
read will bring it out of that state.
Our main user of cached_file is per-sstable index caching.
If the scenario above happens, and the sstable and its associated
cached_file is destroyed, before the 2nd page is hit, cached_file
will not be able to clear all the cache because some of the
pages are unused and not linked.
A page read ahead will be linked into LRU so it doesn't sit in
memory indefinitely. Also allowing for cached_file dtor to
clear all cache if some of those pages brought in advance
aren't fetched later.
A reproducer was added.
Fixes#14814.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#14818
(cherry picked from commit 050ce9ef1d)
In 10c1f1dc80 I fixed
`make_group0_history_state_id_mutation` to use correct timestamp
resolution (microseconds instead of milliseconds) which was supposed to
fix the flakiness of `test_group0_history_clearing_old_entries`.
Unfortunately, the test is still flaky, although now it's failing at a
later step -- this is because I was sloppy and I didn't adjust this
second part of the test to also use microsecond resolution. The test is
counting the number of entries in the `system.group0_history` table that
are older than a certain timestamp, but it's doing the counting using
millisecond resolution, causing it to give results that are off by one
sometimes.
Fix it by using microseconds everywhere.
Fixes#14653Closes#14670
(cherry picked from commit 9d4b3c6036)
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>
(cherry picked from commit 1d8cb32a5d)
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#14764
Currently, when two cells have the same write timestamp
and both are alive or expiring, we compare their value first,
before checking if either of them is expiring
and if both are expiring, comparing their expiration time
and ttl value to determine which of them will expire
later or was written later.
This was based on an early version of Cassandra.
However, the Cassandra implementation rightfully changed in
e225c88a65 ([CASSANDRA-14592](https://issues.apache.org/jira/browse/CASSANDRA-14592)),
where the cell expiration is considered before the cell value.
To summarize, the motivation for this change is three fold:
1. Cassandra compatibility
2. Prevent an edge case where a null value is returned by select query when an expired cell has a larger value than a cell with later expiration.
3. A generalization of the above: value-based reconciliation may cause select query to return a mixture of upserts, if multiple upserts use the same timeastamp but have different expiration times. If the cell value is considered before expiration, the select result may contain cells from different inserts, while reconciling based the expiration times will choose cells consistently from either upserts, as all cells in the respective upsert will carry the same expiration time.
\Fixes scylladb/scylladb#14182
Also, this series:
- updates dml documentation
- updates internal documentation
- updates and adds unit tests and cql pytest reproducing #14182
\Closes scylladb/scylladb#14183
* github.com:scylladb/scylladb:
docs: dml: add update ordering section
cql-pytest: test_using_timestamp: add tests for rewrites using same timestamp
mutation_partition: compare_row_marker_for_merge: consider ttl in case expiry is the same
atomic_cell: compare_atomic_cell_for_merge: update and add documentation
compare_atomic_cell_for_merge: compare value last for live cells
mutation_test: test_cell_ordering: improve debuggability
(cherry picked from commit 87b4606cd6)
Closes#14649
Fixes#11017
When doing writes, storage proxy creates types deriving from abstract_write_response_handler.
These are created in the various scheduling groups executing the write inducing code. They
pick up a group-local reference to the various metrics used by SP. Normally all code
using (and esp. modifying) these metrics are executed in the same scheduling group.
However, if gossip sees a node go down, it will notify listeners, which eventually
calls get_ep_stat and register_metrics.
This code (before this patch) uses _active_ scheduling group to eventually add
metrics, using a local dict as guard against double regs. If, as described above,
we're called in a different sched group than the original one however, this
can cause double registrations.
Fixed here by keeping a reference to creating scheduling group and using this, not
active one, when/if creating new metrics.
Closes#14636
View update routines accept mutation objects.
But what comes out of staging sstable readers is a stream of mutation_fragment_v2 objects.
To build view updates after a repair/streaming, we have to convert the fragment stream into mutations. This is done by piping the stream to mutation_rebuilder_v2.
To keep memory usage limited, the stream for a single partition might have to be split into multiple partial mutation objects. view_update_consumer does that, but in improper way -- when the split/flush happens inside an active range tombstone, the range tombstone isn't closed properly. This is illegal, and triggers an internal error.
This patch fixes the problem by closing the active range tombstone (and reopening in the same position in the next mutation object).
The tombstone is closed just after the last seen clustered position. This is not necessary for correctness -- for example we could delay all processing of the range tombstone until we see its end bound -- but it seems like the most natural semantic.
Backported from c25201c1a3. `view_build_test.cc` needed some tiny adjustments for the backport.
Closes#14619Fixes#14503
* github.com:scylladb/scylladb:
test: view_build_test: add range tombstones to test_view_update_generator_buffering
test: view_build_test: add test_view_udate_generator_buffering_with_random_mutations
view_updating_consumer: make buffer limit a variable
view: fix range tombstone handling on flushes in view_updating_consumer
In mutation_reader_merger and clustering_order_reader_merger, the
operator()() is responsible for producing mutation fragments that will
be merged and pushed to the combined reader's buffer. Sometimes, it
might have to advance existing readers, open new and / or close some
existing ones, which requires calling a helper method and then calling
operator()() recursively.
In some unlucky circumstances, a stack overflow can occur:
- Readers have to be opened incrementally,
- Most or all readers must not produce any fragments and need to report
end of stream without preemption,
- There has to be enough readers opened within the lifetime of the
combined reader (~500),
- All of the above needs to happen within a single task quota.
In order to prevent such a situation, the code of both reader merger
classes were modified not to perform recursion at all. Most of the code
of the operator()() was moved to maybe_produce_batch which does not
recur if it is not possible for it to produce a fragment, instead it
returns std::nullopt and operator()() calls this method in a loop via
seastar::repeat_until_value.
A regression test is added.
Fixes: scylladb/scylladb#14415
Closes#14452
(cherry picked from commit ee9bfb583c)
Closes#14605
This patch adds a full-range tombstone to the compacted mutation.
This raises the coverage of the test. In particular, it reproduces
issue #14503, which should have been caught by this test, but wasn't.
View update routines accept `mutation` objects.
But what comes out of staging sstable readers is a stream of
mutation_fragment_v2 objects.
To build view updates after a repair/streaming, we have to
convert the fragment stream into `mutation`s. This is done by piping
the stream to mutation_rebuilder_v2.
To keep memory usage limited, the stream for a single partition might
have to be split into multiple partial `mutation` objects.
view_update_consumer does that, but in improper way -- when the
split/flush happens inside an active range tombstone, the range
tombstone isn't closed properly. This is illegal, and triggers an
internal error.
This patch fixes the problem by closing the active range tombstone
(and reopening in the same position in the next `mutation` object).
The tombstone is closed just after the last seen clustered position.
This is not necessary for correctness -- for example we could delay
all processing of the range tombstone until we see its end
bound -- but it seems like the most natural semantic.
Fixes#14503
The evictable reader must ensure that each buffer fill makes forward progress, i.e. the last fragment in the buffer has a position larger than the last fragment from the previous buffer-fill. Otherwise, the reader could get stuck in an infinite loop between buffer fills, if the reader is evicted in-between.
The code guranteeing this forward progress had a bug: the comparison between the position after the last buffer-fill and the current last fragment position was done in the wrong direction.
So if the condition that we wanted to achieve was already true, we would continue filling the buffer until partition end which may lead to OOMs such as in #13491.
There was already a fix in this area to handle `partition_start` fragments correctly - #13563 - but it missed that the position comparison was done in the wrong order.
Fix the comparison and adjust one of the tests (added in #13563) to detect this case.
After the fix, the evictable reader starts generating some redundant (but expected) range tombstone change fragments since it's now being paused and resumed. For this we need to adjust mutation source tests which were a bit too specific. We modify `flat_mutation_reader_assertions` to squash the redundant `r_t_c`s.
Fixes#13491Closes#14375
* github.com:scylladb/scylladb:
readers: evictable_reader: don't accidentally consume the entire partition
test: flat_mutation_reader_assertions: squash `r_t_c`s with the same position
(cherry picked from commit 586102b42e)
After c7826aa910, sstable runs are cleaned up together.
The procedure which executes cleanup was holding reference to all
input sstables, such that it could later retry the same cleanup
job on failure.
Turns out it was not taking into account that incremental compaction
will exhaust the input set incrementally.
Therefore cleanup is affected by the 100% space overhead.
To fix it, cleanup will now have the input set updated, by removing
the sstables that were already cleaned up. On failure, cleanup
will retry the same job with the remaining sstables that weren't
exhausted by incremental compaction.
New unit test reproduces the failure, and passes with the fix.
Fixes#14035.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#14038
(cherry picked from commit 23443e0574)
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#14193
With regards to closing the looked-up querier if an exception is thrown. In particular, this requires closing the querier if a semaphore mismatch is detected. Move the table lookup above the line where the querier is looked up, to avoid having to handle the exception from it. As a consequence of closing the querier on the error path, the lookup lambda has to be made a coroutine. This is sad, but this is executed once per page, so its cost should be insignificant when spread over an
entire page worth of work.
Also add a unit test checking that the mismatch is detected in the first place and that readers are closed.
Fixes: #13784Closes#13790
* github.com:scylladb/scylladb:
test/boost/database_test: add unit test for semaphore mismatch on range scans
partition_slice_builder: add set_specific_ranges()
multishard_mutation_query: make reader_context::lookup_readers() exception safe
multishard_mutation_query: lookup_readers(): make inner lambda a coroutine
(cherry picked from commit 1c0e8c25ca)
range_tombstone_change_generator::flush() mishandles the case when two range
tombstones are adjacent and flush(pos, end_of_range=true) is called with pos
equal to the end bound of the lesser-position range tombstone.
In such case, the start change of the greater-position rtc will be accidentally
emitted, and there won't be an end change, which breaks reader assumptions by
ending the stream with an unclosed range tombstone, triggering an assertion.
This is due to a non-strict inequality used in a place where strict inequality
should be used. The modified line was intended to close range tombstones
which end exactly on the flush position, but this is unnecessary because such
range tombstones are handled by the last `if` in the function anyway.
Instead, this line caused range tombstones beginning right after the flush
position to be emitted sometimes.
Fixes https://github.com/scylladb/scylladb/issues/12462Closes#13894
* github.com:scylladb/scylladb:
tests: row_cache: Add reproducer for reader producing missing closing range tombstone
range_tombstone_change_generator: fix an edge case in flush()
Adds a reproducer for #12462.
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 fix range_tombstone_change_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.
Cherry-picked from a717c803c7.
Aggregation query on counter column is failing because forward_service is looking for function with counter as an argument and such function doesn't exist. Instead the long type should be used.
Fixes: #12939Closes#12963
* github.com:scylladb/scylladb:
test:boost: counter column parallelized aggregation test
service:forward_service: use long type when column is counter
(cherry picked from commit 61e67b865a)
The evictable reader must ensure that each buffer fill makes forward
progress, i.e. the last fragment in the buffer has a position larger
than the last fragment from the last buffer-fill. Otherwise, the reader
could get stuck in an infinite loop between buffer fills, if the reader
is evicted in-between.
The code guranteeing this forward change has a bug: when the next
expected position is a partition-start (another partition), the code
would loop forever, effectively reading all there is from the underlying
reader.
To avoid this, add a special case to ignore the progress guarantee loop
altogether when the next expected position is a partition start. In this
case, progress is garanteed anyway, because there is exactly one
partition-start fragment in each partition.
Fixes: #13491Closes#13563
(cherry picked from commit 72003dc35c)
Otherwise the null pointer is dereferenced.
Add a unit test reproducing the issue
and testing this fix.
Fixes#13636
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
(cherry picked from commit 12877ad026)
This patch backports https://github.com/scylladb/scylladb/pull/12710 to branch-5.2. To resolve the conflicts that it's causing, it also includes
* https://github.com/scylladb/scylladb/pull/12680
* https://github.com/scylladb/scylladb/pull/12681Closes#13542
* github.com:scylladb/scylladb:
uda: change the UDF used in a UDA if it's replaced
functions: add helper same_signature method
uda: return aggregate functions as shared pointers
udf: also check reducefunc to confirm that a UDF is not used in a UDA
udf: fix dropping UDFs that share names with other UDFs used in UDAs
pytest: add optional argument for new_function argument types
udt: disallow dropping a user type used in a user function
The purpose of `_stop` is to remember whether the consumption of the
last partition was interrupted or it was consumed fully. In the former
case, the compactor allows retreiving the compaction state for the given
partition, so that its compaction can be resumed at a later point in
time.
Currently, `_stop` is set to `stop_iteration::yes` whenever the return
value of any of the `consume()` methods is also `stop_iteration::yes`.
Meaning, if the consuming of the partition is interrupted, this is
remembered in `_stop`.
However, a partition whose consumption was interrupted is not always
continued later. Sometimes consumption of a partitions is interrputed
because the partition is not interesting and the downstream consumer
wants to stop it. In these cases the compactor should not return an
engagned optional from `detach_state()`, because there is not state to
detach, the state should be thrown away. This was incorrectly handled so
far and is fixed in this patch, but overwriting `_stop` in
`consume_partition_end()` with whatever the downstream consumer returns.
Meaning if they want to skip the partition, then `_stop` is reset to
`stop_partition::no` and `detach_state()` will return a disengaged
optional as it should in this case.
Fixes: #12629Closes#13365
(cherry picked from commit bae62f899d)
Currently, nothing prevents us from dropping a user type
used in a user function, even though doing so may make us
unable to use the function correctly.
This patch prevents this behavior by checking all function
argument and return types when executing a drop type statement
and preventing it from completing if the type is referenced
by any of them.
(cherry picked from commit 86c61828e6)
Inactive readers should only be evicted to free up resources for waiting
readers. Evicting them when waiters are not admitted for any other
reason than resources is wasteful and leads to extra load later on when
these evicted readers have to be recreated end requeued.
This patch changes the logic on both the registering path and the
admission path to not evict inactive readers unless there are readers
actually waiting on resources.
A unit-test is also added, reproducing the overly-agressive eviction and
checking that it doesn't happen anymore.
Fixes: #11803Closes#13286
(cherry picked from commit bd57471e54)
This PR backports 2f4a793457 to branch-5.2. Said patch depends on some other patches that are not part of any release yet.
This PR should apply to 5.1 and 5.0 too.
Closes#13162
* github.com:scylladb/scylladb:
reader_concurrency_semaphore:: clear_inactive_reads(): defer evicting to evict()
reader_permit: expose operator<<(reader_permit::state)
reader_permit: add get_state() accessor
The series fixes the `make_nonforwardable` reader, it shouldn't emit `partition_end` for previous partition after `next_partition()` and `fast_forward_to()`
Fixes: #12249Closes#12978
* github.com:scylladb/scylladb:
flat_mutation_reader_test: cleanup, seastar::async -> SEASTAR_THREAD_TEST_CASE
make_nonforwardable: test through run_mutation_source_tests
make_nonforwardable: next_partition and fast_forward_to when single_partition is true
make_forwardable: fix next_partition
flat_mutation_reader_v2: drop forward_buffer_to
nonforwardable reader: fix indentation
nonforwardable reader: refactor, extract reset_partition
nonforwardable reader: add more tests
nonforwardable reader: no partition_end after fast_forward_to()
nonforwardable reader: no partition_end after next_partition()
nonforwardable reader: no partition_end for empty reader
row_cache: pass partition_start though nonforwardable reader
(cherry picked from commit 46efdfa1a1)
Instead of open-coding the same, in an incomplete way.
clear_inactive_reads() does incomplete eviction in severeal ways:
* it doesn't decrement _stats.inactive_reads
* it doesn't set the permit to evicted state
* it doesn't cancel the ttl timer (if any)
* it doesn't call the eviction notifier on the permit (if there is one)
The list goes on. We already have an evict() method that all this
correctly, use that instead of the current badly open-coded alternative.
This patch also enhances the existing test for clear_inactive_reads()
and adds a new one specifically for `stop()` being called while having
inactive reads.
Fixes: #13048Closes#13049
(cherry picked from commit 2f4a793457)
It's known that reading large cells in reverse cause large allocations.
Source: https://github.com/scylladb/scylladb/issues/11642
The loading is preliminary work for splitting large partitions into
fragments composing a run and then be able to later read such a run
in an efficiency way using the position metadata.
The splitting is not turned on yet, anywhere. Therefore, we can
temporarily disable the loading, as a way to avoid regressions in
stable versions. Large allocations can cause stalls due to foreground
memory eviction kicking in.
The default values for position metadata say that first and last
position include all clustering rows, but they aren't used anywhere
other than by sstable_run to determine if a run is disjoint at
clustering level, but given that no splitting is done yet, it
does not really matter.
Unit tests relying on position metadata were adjusted to enable
the loading, such that they can still pass.
Fixes#11642.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#12979
(cherry picked from commit d73ffe7220)
The CQL binary protocol introduced "unset" values in version 4
of the protocol. Unset values can be bound to variables, which
cause certain CQL fragments to be skipped. For example, the
fragment `SET a = :var` will not change the value of `a` if `:var`
is bound to an unset value.
Unsets, however, are very limited in where they can appear. They
can only appear at the top-level of an expression, and any computation
done with them is invalid. For example, `SET list_column = [3, :var]`
is invalid if `:var` is bound to unset.
This causes the code to be littered with checks for unset, and there
are plenty of tests dedicated to catching unsets. However, a simpler
way is possible - prevent the infiltration of unsets at the point of
entry (when evaluating a bind variable expression), and introduce
guards to check for the few cases where unsets are allowed.
This is what this long patch does. It performs the following:
(general)
1. unset is removed from the possible values of cql3::raw_value and
cql3::raw_value_view.
(external->cql3)
2. query_options is fortified with a vector of booleans,
unset_bind_variable_vector, where each boolean corresponds to a bind
variable index and is true when it is unset.
3. To avoid churn, two compatiblity structs are introduced:
cql3::raw_value{,_view}_vector_with_unset, which can be constructed
from a std::vector<raw_value{,_view/}>, which is what most callers
have. They can also be constructed with explicit unset vectors, for
the few cases they are needed.
(cql3->variables)
4. query_options::get_value_at() now throws if the requested bind variable
is unset. This replaces all the throwing checks in expression evaluation
and statement execution, which are removed.
5. A new query_options::is_unset() is added for the users that can tolerate
unset; though it is not used directly.
6. A new cql3::unset_operation_guard class guards against unsets. It accepts
an expression, and can be queried whether an unset is present. Two
conditions are checked: the expression must be a singleton bind
variable, and at runtime it must be bound to an unset value.
7. The modification_statement operations are split into two, via two
new subclasses of cql3::operation. cql3::operation_no_unset_support
ignores unsets completely. cql3::operation_skip_if_unset checks if
an operand is unset (luckily all operations have at most one operand that
tolerates unset) and applies unset_operation_guard to it.
8. The various sites that accept expressions or operations are modified
to check for should_skip_operation(). This are the loops around
operations in update_statement and delete_statement, and the checks
for unset in attributes (LIMIT and PER PARTITION LIMIT)
(tests)
9. Many unset tests are removed. It's now impossible to enter an
unset value into the expression evaluation machinery (there's
just no unset value), so it's impossible to test for it.
10. Other unset tests now have to be invoked via bind variables,
since there's no way to create an unset cql3::expr::constant.
11. Many tests have their exception message match strings relaxed.
Since unsets are now checked very early, we don't know the context
where they happen. It would be possible to reintroduce it (by adding
a format string parameter to cql3::unset_operation_guard), but it
seems not to be worth the effort. Usage of unsets is rare, and it is
explicit (at least with the Python driver, an unset cannot be
introduced by ommission).
I tried as an alternative to wrap cql3::raw_value{,_view} (that doesn't
recognize unsets) with cql3::maybe_unset_value (that does), but that
caused huge amounts of churn, so I abandoned that in favor of the
current approach.
Closes#12517
Make it clear that the table stores the snapshot configuration, which is
not necessarily the currently operating configuration (the last one
appended to the log).
In the future we plan to have a separate virtual table for showing the
currently operating configuration, perhaps we will call it
`system.raft_config`.
In test_apply_is_atomic, a basic form of exception testing is used.
There is failure_injecting_allocation_strategy, which however is not
used for any allocation, since for some reason,
`with_allocator(r.allocator()` is used instead of
`with_allocator(alloc`. Fix that.
Closes#12354
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
Inferring shard from generation is long gone. We still use it in
some scripts, but that's no longer needed in Scylla, when loading
the SSTables, and it also conflicts with ongoing work of UUID-based
generations.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#12476
The CQL binary protocol version 3 was introduced in 2014. All Scylla
version support it, and Cassandra versions 2.1 and newer.
Versions 1 and 2 have 16-bit collection sizes, while protocol 3 and newer
use 32-bit collection sizes.
Unfortunately, we implemented support for multiple serialization formats
very intrusively, by pushing the format everywhere. This avoids the need
to re-serialize (sometimes) but is quite obnoxious. It's also likely to be
broken, since it's almost untested and it's too easy to write
cql_serialization_format::internal() instead of propagating the client
specified value.
Since protocols 1 and 2 are obsolete for 9 years, just drop them. It's
easy to verify that they are no longer in use on a running system by
examining the `system.clients` table before upgrade.
Fixes#10607Closes#12432
* github.com:scylladb/scylladb:
treewide: drop cql_serialization_format
cql: modification_statement: drop protocol check for LWT
transport: drop cql protocol versions 1 and 2
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 commit removes consume_in_reverse::legacy_half_reverse, an option
once used to indicate that the given key ranges are sorted descending,
based on the clustering key of the start of the range, and that the
range tombstones inside partition would be sorted (descending, as all
the mutation fragments would) according to their end (but range
tombstone would still be stored according to their start bound).
As it turns out, mutation::consume, when called with legacy_half_reverse
option produces invalid fragment stream, one where all the row
tombstone changes come after all the clustering rows. This was not an
issue, since when constructing results from the query, Scylla would not
pass the tombstones to the client, but instead compact data beforehand.
In this commit, the consume_in_reverse::legacy_half_reverse is removed,
along with all the uses.
As for the swap out in mutation_partition.cc in query_mutation and
to_data_query_result:
The downstream was not prepared to deal with legacy_half_reverse.
mutation::consume contains
```
if (reverse == consume_in_reverse::yes) {
while (!(stop_opt = consume_clustering_fragments<consume_in_reverse::yes>(_ptr->_schema, partition, consumer, cookie, is_preemptible::yes))) {
co_await yield();
}
} else {
while (!(stop_opt = consume_clustering_fragments<consume_in_reverse::no>(_ptr->_schema, partition, consumer, cookie, is_preemptible::yes))) {
co_await yield();
}
}
```
So why did it work at all? to_data_query_result deals with a single slice.
The used consumer (compact_for_query_v2) compacts-away the range tombstone
changes, and thus the only difference between the consume_in_reverse::no
and consume_in_reverse::yes was that one was ordered increasing wrt. ckeys
and the second one was ordered decreasing. This property is maintained if
we swap out for the consume_in_reverse::yes format.
Refs: #12353Closes#12453
* github.com:scylladb/scylladb:
mutation{,_consumer,_partition}: remove consume_in_reverse::legacy_half_reverse
mutation_partition_view: treat query::partition_slice::option::reversed in to_data_query_result as consume_in_reverse::yes
mutation: move consume_in_reverse def to mutation_consumer.hh
Convert decompressed temporary buffers into tracked buffers just before
returning them to the upper layer. This ensures these buffers are known
to the reader concurrency semaphore and it has an accurate view of the
actual memory consumption of reads.
Fixes: #12448Closes#12454
The main source of big allocations in the WASM UDF implementation
is the WASM Linear Memory. We do not want Scylla to crash even if
a memory allocation for the WASM Memory fails, so we assert that
an exception is thrown instead.
The wasmtime runtime does not actually fail on an allocation failure
(assuming the memory allocator does not abort and returns nullptr
instead - which our seastar allocator does). What happens then
depends on the failed allocation handling of the code that was
compiled to WASM. If the original code threw an exception or aborted,
the resulting WASM code will trap. To make sure that we can handle
the trap, we need to allow wasmtime to handle SIGILL signals, because
that what is used to carry information about WASM traps.
The new test uses a special WASM Memory allocator that fails after
n allocations, and the allocations include both memory growth
instructions in WASM, as well as growing memory manually using the
wasmtime API.
Signed-off-by: Wojciech Mitros <wojciech.mitros@scylladb.com>
The wasmtime runtime allocates memory for the executable code of
the WASM programs using mmap and not the seastar allocator. As
a result, the memory that Scylla actually uses becomes not only
the memory preallocated for the seastar allocator but the sum of
that and the memory allocated for executable codes by the WASM
runtime.
To keep limiting the memory used by Scylla, we measure how much
memory do the WASM programs use and if they use too much, compiled
WASM UDFs (modules) that are currently not in use are evicted to
make room.
To evict a module it is required to evict all instances of this
module (the underlying implementation of modules and instances uses
shared pointers to the executable code). For this reason, we add
reference counts to modules. Each instance using a module is a
reference. When an instance is destroyed, a reference is removed.
If all references to a module are removed, the executable code
for this module is deallocated.
The eviction of a module is actually acheved by eviction of all
its references. When we want to free memory for a new module we
repeatedly evict instances from the wasm_instance_cache using its
LRU strategy until some module loses all its instances. This
process may not succeed if the instances currently in use (so not
in the cache) use too much memory - in this case the query also
fails. Otherwise the new module is added to the tracking system.
This strategy may evict some instances unnecessarily, but evicting
modules should not happen frequently, and any more efficient
solution requires an even bigger intervention into the code.
Different users may require different limits for their UDFs. This
patch allows them to configure the size of their cache of wasm,
the maximum size of indivitual instances stored in the cache, the
time after which the instances are evicted, the fuel that all wasm
UDFs are allowed to consume before yielding (for the control of
latency), the fuel that wasm UDFs are allowed to consume in total
(to allow performing longer computations in the UDF without
detecting an infinite loop) and the hard limit of the size of UDFs
that are executed (to avoid large allocations)
The new implementation for WASM UDFs allows executing the UDFs
in pieces. This commit adds a test asserting that the UDF is in fact
divided and that each of the execution segments takes no longer than
1ms.
This commit removes consume_in_reverse::legacy_half_reverse, an option
once used to indicate that the given key ranges are sorted descending,
based on the clustering key of the start of the range, and that the
range tombstones inside partition would be sorted (descending, as all
the mutation fragments would) according to their end (but range
tombstone would still be stored according to their start bound).
As it turns out, mutation::consume, when called with legacy_half_reverse
option produces invalid fragment stream, one where all the row
tombstone changes come after all the clustering rows. This was not an
issue, since when constructing results from the query, Scylla would not
pass the tombstones to the client, but instead compact data beforehand.
In this commit, the consume_in_reverse::legacy_half_reverse is removed,
along with all the uses.
As for the swap out in mutation_partition.cc in query_mutation and
to_data_query_result:
The downstream was not prepared to deal with legacy_half_reverse.
mutation::consume contains
```
if (reverse == consume_in_reverse::yes) {
while (!(stop_opt = consume_clustering_fragments<consume_in_reverse::yes>(_ptr->_schema, partition, consumer, cookie, is_preemptible::yes))) {
co_await yield();
}
} else {
while (!(stop_opt = consume_clustering_fragments<consume_in_reverse::no>(_ptr->_schema, partition, consumer, cookie, is_preemptible::yes))) {
co_await yield();
}
}
```
So why did it work at all? to_data_query_result deals with a single slice.
The used consumer (compact_for_query_v2) compacts-away the range tombstone
changes, and thus the only difference between the consume_in_reverse::no
and consume_in_reverse::yes was that one was ordered increasing wrt. ckeys
and the second one was ordered decreasing. This property is maintained if
we swap out for the consume_in_reverse::yes format.
Run tests for parallelized aggregation with
`enable_parallelized_aggregation` set always to true, so the tests work
even if the default value of the option is false.
Closes#12409
Now that we don't accept cql protocol version 1 or 2, we can
drop cql_serialization format everywhere, except when in the IDL
(since it's part of the inter-node protocol).
A few functions had duplicate versions, one with and one without
a cql_serialization_format parameter. They are deduplicated.
Care is taken that `partition_slice`, which communicates
the cql_serialization_format across nodes, still presents
a valid cql_serialization_format to other nodes when
transmitting itself and rejects protocol 1 and 2 serialization\
format when receiving. The IDL is unchanged.
One test checking the 16-bit serialization format is removed.
database_test in timing out because it's having to run the tests calling
do_with_cql_env_and_compaction_groups 3x, one for each compaction group
setting. reduce it to 2 settings instead of 3 if running in debug mode.
Refs #12396.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#12421
Extends mutation_test to run the tests with more than one
compaction group, in addition to a single one (default).
Piggyback on existing tests. Avoids duplication.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Extends database_test to run the tests with more than one
compaction group, in addition to a single one (default).
Piggyback on existing tests. Avoids duplication.
Caught a bug when snapshotting, in implementation of
table::can_flush(), showing its usefulness.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
