Incremented the components_memory_reclaim_threshold config's default
value to 0.2 as the previous value was too strict and caused unnecessary
eviction in otherwise healthy clusters.
Fixes#18607
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 3d7d1fa72a)
Closes#19011
PR https://github.com/scylladb/scylladb/pull/17771 introduced a threshold for the total memory used by all bloom filters across SSTables. When the total usage surpasses the threshold, the largest bloom filter will be removed from memory, bringing the total usage back under the threshold. This PR adds support for reloading such reclaimed bloom filters back into memory when memory becomes available (i.e., within the 10% of available memory earmarked for the reclaimable components).
The SSTables manager now maintains a list of all SSTables whose bloom filter was removed from memory and attempts to reload them when an SSTable, whose bloom filter is still in memory, gets deleted. The manager reloads from the smallest to the largest bloom filter to maximize the number of filters being reloaded into memory.
Backported from https://github.com/scylladb/scylladb/pull/18186 to 5.2.
Closes#18666
* github.com:scylladb/scylladb:
sstable_datafile_test: add testcase to test reclaim during reload
sstable_datafile_test: add test to verify auto reload of reclaimed components
sstables_manager: reload previously reclaimed components when memory is available
sstables_manager: start a fiber to reload components
sstable_directory_test: fix generation in sstable_directory_test_table_scan_incomplete_sstables
sstable_datafile_test: add test to verify reclaimed components reload
sstables: support reloading reclaimed components
sstables_manager: add new intrusive set to track the reclaimed sstables
sstable: add link and comparator class to support new instrusive set
sstable: renamed intrusive list link type
sstable: track memory reclaimed from components per sstable
sstable: rename local variable in sstable::total_reclaimable_memory_size
Even when configured to not do any validation at all, the validator still did some. This small series fixes this, and adds a test to check that validation levels in general are respected, and the validator doesn't validate more than it is asked to.
Fixes: #18662
(cherry picked from commit f6511ca1b0)
(cherry picked from commit e7b07692b6)
(cherry picked from commit 78afb3644c)
Refs #18667Closes#18723
* github.com:scylladb/scylladb:
test/boost/mutation_fragment_test.cc: add test for validator validation levels
mutation: mutation_fragment_stream_validating_filter: fix validation_level::none
mutation: mutation_fragment_stream_validating_filter: add raises_error ctor parameter
when we convert timestamp into string it must look like: '2017-12-27T11:57:42.500Z'
it concerns any conversion except JSON timestamp format
JSON string has space as time separator and must look like: '2017-12-27 11:57:42.500Z'
both formats always contain milliseconds and timezone specification
Fixes#14518Fixes#7997Closes#14726Fixes#16575
(cherry picked from commit ff721ec3e3)
Closes#18852
We have to account for moved objects as well
as copied objects so they will be balanced with
the respective `del_live_object` calls called
by the destructor.
However, since chunked_vector requires the
value_type to be nothrow_move_constructible,
just count the additional live object, but
do not modify _countdown or, respectively, throw
an exception, as this should be considered only
for the default and copy constructors.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
The testcase uses an sstable whose mutation key and the generation are
owned by different shards. Due to this, when process_sstable_dir is
called, the sstable gets loaded into a different shard than the one that
was intended. This also means that the sstable and the sstable manager
end up in different shards.
The following patch will introduce a condition variable in sstables
manager which will be signalled from the sstables. If the sstable and
the sstable manager are in different shards, the signalling will cause
the testcase to fail in debug mode with this error : "Promise task was
set on shard x but made ready on shard y". So, fix it by supplying
appropriate generation number owned by the same shard which owns the
mutation key as well.
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
(cherry picked from commit 24064064e9)
When reclaiming memory from bloom filters, do not remove them from
_recognised_components, as that leads to the on-disk filter component
being left back on disk when the SSTable is deleted.
Fixes#18398
Signed-off-by: Lakshmi Narayanan Sreethar <lakshmi.sreethar@scylladb.com>
Closesscylladb/scylladb#18400
(cherry picked from commit 6af2659b57)
Closes#18437
instead of casting / comparing the count of duration unit, let's just
compare the durations, so that boost.test is able to print the duration
in a more informative and user friendly way (line wrapped)
test/boost/error_injection_test.cc(167): fatal error:
in "test_inject_future_disabled":
critical check wait_time > sleep_msec has failed [23839ns <= 10ms]
Refs #15902
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
(cherry picked from commit 1d33a68dd7)
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
(cherry picked from commit 76f0d5e35b)
Closes#17694
While describing materialized view, print `synchronous_updates` option
only if the tag is present in schema's extensions map. Previously if the
key wasn't present, the default (false) value was printed.
Fixes: #14924Closes#14928
(cherry picked from commit b92d47362f)
Table properties validation is performed on statement execution.
Thus, when one attempts to create a table with invalid options,
an incorrect command gets committed in Raft. But then its
application fails, leading to a raft machine being stopped.
Check table properties when create and alter statements are prepared.
The error is no longer returned as an exceptional future, but it
is thrown. Adjust the tests accordingly.
(cherry picked from commit 60fdc44bce)
TWCS tables require partition estimation adjustment as incoming streaming data can be segregated into the time windows.
Turns out we had two problems in this area that leads to suboptimal bloom filters.
1) With off-strategy enabled, data segregation is postponed, but partition estimation was adjusted as if segregation wasn't postponed. Solved by not adjusting estimation if segregation is postponed.
2) With off-strategy disabled, data segregation is not postponed, but streaming didn't feed any metadata into partition estimation procedure, meaning it had to assume the max windows input data can be segregated into (100). Solved by using schema's default TTL for a precise estimation of window count.
For the future, we want to dynamically size filters (see https://github.com/scylladb/scylladb/issues/2024), especially for TWCS that might have SSTables that are left uncompacted until they're fully expired, meaning that the system won't heal itself in a timely manner through compaction on a SSTable that had partition estimation really wrong.
Fixes https://github.com/scylladb/scylladb/issues/15704.
Closes scylladb/scylladb#15938
* github.com:scylladb/scylladb:
streaming: Improve partition estimation with TWCS
streaming: Don't adjust partition estimate if segregation is postponed
(cherry picked from commit 64d1d5cf62)
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#16672
Lists can grow very big. Let's use a chunked vector to prevent large contiguous
allocations.
Fixes: #15302.
Closesscylladb/scylladb#15428
(cherry picked from commit 62a8a31be7)
Having values of the duration type is not allowed for clustering
columns, because duration can't be ordered. This is correctly validated
when creating a table but do not validated when we alter the type.
Fixes#12913Closesscylladb/scylladb#16022
(cherry picked from commit bd73536b33)
The implementation of "SELECT TOJSON(t)" or "SELECT JSON t" for a column
of type "time" forgot to put the time string in quotes. The result was
invalid JSON. This is patch is a one-liner fixing this bug.
This patch also removes the "xfail" marker from one xfailing test
for this issue which now starts to pass. We also add a second test for
this issue - the existing test was for "SELECT TOJSON(t)", and the second
test shows that "SELECT JSON t" had exactly the same bug - and both are
fixed by the same patch.
We also had a test translated from Cassandra which exposed this bug,
but that test continues to fail because of other bugs, so we just
need to update the xfail string.
The patch also fixes one C++ test, test/boost/json_cql_query_test.cc,
which enshrined the *wrong* behavior - JSON output that isn't even
valid JSON - and had to be fixed. Unlike the Python tests, the C++ test
can't be run against Cassandra, and doesn't even run a JSON parser
on the output, which explains how it came to enshrine wrong output
instead of helping to discover the bug.
Fixes#7988
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Closesscylladb/scylladb#16121
(cherry picked from commit 8d040325ab)
reconcilable_result_builder passes range tombstone changes to _rt_assembler
using table schema, not query schema.
This means that a tombstone with bounds (a; b), where a < b in query schema
but a > b in table schema, will not be emitted from mutation_query.
This is a very serious bug, because it means that such tombstones in reverse
queries are not reconciled with data from other replicas.
If *any* queried replica has a row, but not the range tombstone which deleted
the row, the reconciled result will contain the deleted row.
In particular, range deletes performed while a replica is down will not
later be visible to reverse queries which select this replica, regardless of the
consistency level.
As far as I can see, this doesn't result in any persistent data loss.
Only in that some data might appear resurrected to reverse queries,
until the relevant range tombstone is fully repaired.
This series fixes the bug and adds a minimal reproducer test.
Fixes#10598Closesscylladb/scylladb#16003
* github.com:scylladb/scylladb:
mutation_query_test: test that range tombstones are sent in reverse queries
mutation_query: properly send range tombstones in reverse queries
(cherry picked from commit 65e42e4166)
The execution loop consumes permits from the _ready_list and executes
them. The _ready_list usually contains a single permit. When the
_ready_list is not empty, new permits are queued until it becomes empty.
The execution loops relies on admission checks triggered by the read
releasing resouces, to bring in any queued read into the _ready_list,
while it is executing the current read. But in some cases the current
read might not free any resorces and thus fail to trigger an admission
check and the currently queued permits will sit in the queue until
another source triggers an admission check.
I don't yet know how this situation can occur, if at all, but it is
reproducible with a simple unit test, so it is best to cover this
corner-case in the off-chance it happens in the wild.
Add an explicit admission check to the execution loop, after the
_ready_list is exhausted, to make sure any waiters that can be admitted
with an empty _ready_list are admitted immediately and execution
continues.
Fixes: #13540Closes#13541
(cherry picked from commit b790f14456)
database_test is failing sporadically and the cause was traced back
to commit e3e7c3c7e5.
The commit forces a subset of tests in database_test, to run once
for each of predefined x_log2_compaction_group settings.
That causes two problems:
1) test becomes 240% slower in dev mode.
2) queries on system.auth is timing out, and the reason is a small
table being spread across hundreds of compaction groups in each
shard. so to satisfy a range scan, there will be multiple hops,
making the overhead huge. additionally, the compaction group
aware sstable set is not merged yet. so even point queries will
unnecessarily scan through all the groups.
Fixes#13660.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#13851
(cherry picked from commit a7ceb987f5)
Schema digest is calculated by querying for mutations of all schema
tables, then compacting them so that all tombstones in them are
dropped. However, even if the mutation becomes empty after compaction,
we still feed its partition key. If the same mutations were compacted
prior to the query, because the tombstones expire, we won't get any
mutation at all and won't feed the partition key. So schema digest
will change once an empty partition of some schema table is compacted
away.
Tombstones expire 7 days after schema change which introduces them. If
one of the nodes is restarted after that, it will compute a different
table schema digest on boot. This may cause performance problems. When
sending a request from coordinator to replica, the replica needs
schema_ptr of exact schema version request by the coordinator. If it
doesn't know that version, it will request it from the coordinator and
perform a full schema merge. This adds latency to every such request.
Schema versions which are not referenced are currently kept in cache
for only 1 second, so if request flow has low-enough rate, this
situation results in perpetual schema pulls.
After ae8d2a550d (5.2.0), it is more liekly to
run into this situation, because table creation generates tombstones
for all schema tables relevant to the table, even the ones which
will be otherwise empty for the new table (e.g. computed_columns).
This change inroduces a cluster feature which when enabled will change
digest calculation to be insensitive to expiry by ignoring empty
partitions in digest calculation. When the feature is enabled,
schema_ptrs are reloaded so that the window of discrepancy during
transition is short and no rolling restart is required.
A similar problem was fixed for per-node digest calculation in
c2ba94dc39e4add9db213751295fb17b95e6b962. Per-table digest calculation
was not fixed at that time because we didn't persist enabled features
and they were not enabled early-enough on boot for us to depend on
them in digest calculation. Now they are enabled before non-system
tables are loaded so digest calculation can rely on cluster features.
Fixes#4485.
Manually tested using ccm on cluster upgrade scenarios and node restarts.
Closes#14441
* github.com:scylladb/scylladb:
test: schema_change_test: Verify digests also with TABLE_DIGEST_INSENSITIVE_TO_EXPIRY enabled
schema_mutations, migration_manager: Ignore empty partitions in per-table digest
migration_manager, schema_tables: Implement migration_manager::reload_schema()
schema_tables: Avoid crashing when table selector has only one kind of tables
(cherry picked from commit cf81eef370)
Commit 8c4b5e4 introduced an optimization which only
calculates max purgeable timestamp when a tombstone satisfy the
grace period.
Commit 'repair: Get rid of the gc_grace_seconds' inverted the order,
probably under the assumption that getting grace period can be
more expensive than calculating max purgeable, as repair-mode GC
will look up into history data in order to calculate gc_before.
This caused a significant regression on tombstone heavy compactions,
where most of tombstones are still newer than grace period.
A compaction which used to take 5s, now takes 35s. 7x slower.
The reason is simple, now calculation of max purgeable happens
for every single tombstone (once for each key), even the ones that
cannot be GC'ed yet. And each calculation has to iterate through
(i.e. check the bloom filter of) every single sstable that doesn't
participate in compaction.
Flame graph makes it very clear that bloom filter is a heavy path
without the optimization:
45.64% 45.64% sstable_compact sstable_compaction_test_g
[.] utils::filter::bloom_filter::is_present
With its resurrection, the problem is gone.
This scenario can easily happen, e.g. after a deletion burst, and
tombstones becoming only GC'able after they reach upper tiers in
the LSM tree.
Before this patch, a compaction can be estimated to have this # of
filter checks:
(# of keys containing *any* tombstone) * (# of uncompacting sstable
runs[1])
[1] It's # of *runs*, as each key tend to overlap with only one
fragment of each run.
After this patch, the estimation becomes:
(# of keys containing a GC'able tombstone) * (# of uncompacting
runs).
With repair mode for tombstone GC, the assumption, that retrieval
of gc_before is more expensive than calculating max purgeable,
is kept. We can revisit it later. But the default mode, which
is the "timeout" (i.e. gc_grace_seconds) one, we still benefit
from the optimization of deferring the calculation until
needed.
Cherry picked from commit 38b226f997
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Fixes#14091.
Closes#13908
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Closes#15744
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.
