The `test_max_cells` test was flaky due to `std::bad_alloc` caused by Seastar buddy allocator fragmentation. The root causes are:
1. The doubling loop with 24 iterations of CREATE/INSERT/DROP fragmented the allocator
2. The test built the whole batch as a single string that takes contiguous memory
Also, some iterations inserted zero rows, but still did CREATE/DROP table which also contributed to the fragmentation.
This patch series:
- Skips iterations that insert zero rows
- Creates the table once, truncates it after each test iteration
- Switches to prepared statements
Investigation results are presented in detail in https://scylladb.atlassian.net/browse/SCYLLADB-1645
Fixes SCYLLADB-1645
CI stability improvement. Backport to versions that have this test.
Closesscylladb/scylladb#29759
* github.com:scylladb/scylladb:
test: prepare max cells inserts
test: reuse max cells schema
test: limits: skip empty max cells iterations
Switch from raw CQL batch string to using a prepared statement.
The old approach constructed the entire 50-row batch as a single
CQL text string (~19.8 MiB with 32768 column names spelled out
per row). This caused large contiguous allocations in the server.
Fixes SCYLLADB-1645
Extract table creation into _create_max_cell_count_table(). Call
it once before the loop instead of creating and dropping the table
on every iteration. Use TRUNCATE instead of DROP TABLE between
iterations to clear data while keeping the schema.
This avoids repeated schema operations that fragment the Seastar
buddy allocator's address space with scattered small allocations.
Refs SCYLLADB-1645
The doubling loop in test_max_cells started from cells=1. Since
each row has MAX_CELLS_COLUMNS (32768) cells, iterations where
cells < MAX_CELLS_COLUMNS produced zero rows (cells // columns = 0).
Those iterations only did CREATE TABLE / DROP TABLE with no data
inserted.
Start the loop from MAX_CELLS_COLUMNS and use a while loop.
Co-authored-by: Dario Mirovic <dario.mirovic@scylladb.com>
Refs SCYLLADB-1645
When a partition key or clustering key value exceeds the 64 KiB limit
(65535 bytes serialized), Scylla used to raise a generic
std::runtime_error "Key size too large: N > M" from the low-level
compound-key serializer. That error surfaced to clients as a CQL
server error (code 0x0000, "NoHostAvailable"-looking), which is both
ugly and incompatible with Cassandra - Cassandra returns a clean
InvalidRequest with the message "Key length of N is longer than
maximum of M".
Fix this at the single chokepoint: compound_type::serialize_value in
keys/compound.hh. The serializer is on every path that materializes a
key - INSERT/UPDATE/DELETE/BATCH build mutations through it, and
SELECT builds partition and clustering ranges through it - so a single
throw replacement produces a clean InvalidRequest consistently across
all paths and all key shapes (single, compound PK, composite CK).
The previous approach on this PR branch patched three call sites in
cql3/restrictions/statement_restrictions.cc, which only covered
SELECT, duplicated the check, and placed it mid-restrictions code
(flagged in review). Dropping those changes in favour of the
root-cause fix here.
Un-xfail the tests this fixes:
- test/cqlpy/test_key_length.py: test_insert_65k_pk, test_insert_65k_ck,
test_where_65k_pk, test_where_65k_ck, test_insert_65k_ck_composite,
test_insert_total_compound_pk_err, test_insert_total_composite_ck_err.
- test/cqlpy/cassandra_tests/.../insert_test.py: testPKInsertWithValueOver64K,
testCKInsertWithValueOver64K.
- test/cqlpy/cassandra_tests/.../select_test.py: testPKQueryWithValueOver64K.
test_insert_65k_pk_compound stays xfail: its oversized value gets
rejected by the Python driver's CQL wire-protocol encoder (see
CASSANDRA-19270) before reaching the server, so the fix can't apply.
Updated its reason. testCKQueryWithValueOver64K stays xfail with an
updated reason: Cassandra silently returns empty for an oversized
clustering key in WHERE, while Scylla now throws InvalidRequest - a
deliberate choice mirroring the partition-key case, documented in
the discussion on #10366.
Add three tight-boundary tests (addressing review feedback on the
previous revision) that pin MAX+1 behaviour for SELECT and INSERT of
both partition and clustering keys.
Update test/cluster/dtest/limits_test.py to match the new message
("Key length of \\d+ is longer than maximum of 65535").
fixes#10366fixes#12247
Co-authored-by: Alexander Turetskiy <someone.tur@gmail.com>
Closesscylladb/scylladb#23433
Migrate runtime pytest.skip() calls across 34 files to use the typed
skip_env() wrapper from test.pylib.skip_types.
These sites skip at runtime because a required feature, config option,
library version, build mode, or runtime topology is not available.
Also fixes 'raise pytest.skip(...)' in test_audit.py — skip_env()
already raises internally, so the explicit raise was incorrect.
Each file gains one new import:
from test.pylib.skip_types import skip_env
Set `lsa-timing` logger log level to `debug`. This will help with
the analysis of the whole spectrum of memory reclaim operation
times and memory sizes.
Refs #25097
Copy limits_test.py from scylla-dtest to test/cluster/dtest/limits_test.py.
Add license header.
Disable it for `debug`, `dev`, and `release` mode.
Refs #25097
