commitlog was changed to use fragmented_temporary_buffer::ostream (db::commitlog::output).
So if there are discontiguous small memory blocks, they can be used to satisfy
an allocation even if no contiguous memory blocks are available.
To prevent that, as Avi suggested, this change allocates in 128K blocks
and frees the last one to succeed (so that we won't fail on allocating continuations).
Fixes#8028
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20210203100333.862036-1-bhalevy@scylladb.com>
"
Currently inactive readers are stored in two different places:
* reader concurrency semaphore
* querier cache
With the latter registering its inactive readers with the former. This
is an unnecessarily complex (and possibly surprising) setup that we want
to move away from. This series solves this by moving the responsibility
if storing of inactive reads solely to the reader concurrency semaphore,
including all supported eviction policies. The querier cache is now only
responsible for indexing queriers and maintaining relevant stats.
This makes the ownership of the inactive readers much more clear,
hopefully making Benny's work on introducing close() and abort() a
little bit easier.
Tests: unit(release, debug:v1)
"
* 'unify-inactive-readers/v2' of https://github.com/denesb/scylla:
reader_concurrency_semaphore: store inactive readers directly
querier_cache: store readers in the reader concurrency semaphore directly
querier_cache: retire memory based cache eviction
querier_cache: delegate expiry to the reader_concurrency_semaphore
reader_concurrency_semaphore: introduce ttl for inactive reads
querier_cache: use new eviction notify mechanism to maintain stats
reader_concurrency_semaphore: add eviction notification facility
reader_concurrency_semaphore: extract evict code into method evict()
This is the continuaiton of the row-cache performance
improvements, this time -- the rework of clustering keys part.
The goal is to solve the same set of problems:
- logN eviction complexity
- deep and sparse tree
Unlike partitions, this cache has one big feature that makes it
impossible to just use existing B+ tree:
There's no copyable key at hands. The clustering key is the
managed_bytes() that is not nothrow-copy-constructibe, neither
it's hash-able for lookup due to prefix lookup.
Thus the choice is the B-tree, which is also N-ary one, but
doesn't copy keys around.
B-trees are like B+, but can have key:data pairs in inner nodes,
thus those nodes may be significantly bigger then B+ ones, that
have data-s only in leaf trees. Not to make the memory footprint
worse, the tree assumes that keys and data live on the same object
(the rows_entry one), and the tree itself manages only the key
pointers.
Not to invalidate iterators on insert/remove the tree nodes keep
pointers on keys, not the keys themselves.
The tree uses tri-compare instead of less-compare. This makes the
.find and .lower_bound methods do ~10% less comparisons on random
insert/lookup test.
Numbers:
- memory_footprint: B-tree master
rows_entry size: 216 232
1 row
in-cache: 968 960 (because of dummy entry)
in-memtable: 1006 1022
100 rows
in-cache: 50774 50856
in-memtable: 50620 50918
- mutation_test: B-tree master
tps.average: 891177 833896
- simple_query: B-tree master
tps.median: 71807 71656
tps.maximum: 71847 71708
* xemul/clustering-cache-over-btree-4:
mutation_partition: Save one keys comparison
partition_snapshot_row_cursor: Remove rows pointer
mutation_partition: Use B-tree insertion sugar
perf-test : Print B-tree sizes
mutation_partition: Switch cache of rows onto B-tree
partition_snapshot_reader: Rename cmp to less for explicity
mutation_partition: Make insertion bullet-proof
mutation_partition: Use tri-compare in non-set places
flat_mutation_reader: Use clear() in destroy_current_mutation()
rows_entry: Generalize compare
utils: Intrusive B-tree (with tests)
tests: Generalize bptree compaction test
tests: Generalize bptree stress test
Fixes#7615
Makes the CL writer interface N-valued (though still 1 for the "old" paths). Adds a new write path to input N mutations -> N rp_handles.
Guarantees that all entries are written or none are, and that they will be flushed to disk together.
Small test included.
Closes#7616
* github.com:scylladb/scylla:
commitlog_test: Add multi-entry write test
commitlog: Add "add_entries" call to allow inputting N mutations
commitlog: Make commitlog entries optionally multi-entry
commitlog: Move entry_writer definition to cc file
Whenever we push a fragment, we check whether the buffer is
full and return proceed::no if so, so that the state machine pauses
and lets the consumer continue. This patch adds an additional
condition - if preemption is needed, we also return proceed::no.
This drops us back to the outer loop
(in sstable_mutation_reader::fill_buffer), which will yield to
the reactor as part of seastar::do_until().
Two cases (partition_start and partition_end) did not have the
check for is_buffer_full(); it is added now. This can trigger
is the partition has no rows.
Unlike the previous attempt, push_ready_fragments() is not touched.
The extra preemption opportunities triggered a preexisting bug in
clustering_ranges_walker; it is fixed in the first patch of the series.
I tested this by reading from a large partition with a simple
schema (pk int, ck int, primary key(pk, ck)) with BYPASS CACHE.
However, even without the patch I only got sporadic stalls
with the detector set to 1ms, so it's possible I'm not testing
correctly.
Test: unit (dev, debug, release)
Fixes#7883.
Closes#7928
* github.com:scylladb/scylla:
sstable: reader: preempt after every fragment
clustering_range_walker: fix false discontiguity detected after a static row
Rather than asserting, as seen in #7977.
This shouldn't crash the server in production.
Add unit test that reproduces this scenario
and verifies the internal error exception.
Fixes#7977
Test: unit(release)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20210201163051.1775536-1-bhalevy@scylladb.com>
"
This series extends the scylla_metadata sstable component
to hold an optional testual description of the sstable origin.
It describes where the sstables originated from
(e.g. memtable, repair, streaming, compaction, etc.)
The origin string is provided by the sstable writer via
sstable_writer_config, written to the scylla_metadata component,
and loaded on sstable::load().
A get_origin() method was added to class sstable to retrieve
its origin. It returns an empty string by default if the origin
is missing.
Compaction now logs the sstable origin for each sstable it
compacts, and it generates the sstable origin for all sstables
in generates. Regular compaction origin is simply set to "compaction"
while other compaction types are mentioned by name, as
"cleanup", "resharding", "reshaping", etc.
A unit test was added to test the sstable_origin by writing either
an empty origin and a random string, and then comparing
the origin retrieved by sstable::load to the one written.
Test: unit(release)
Fixes#7880
"
* tag 'sstable-origin-v2' of github.com:bhalevy/scylla:
compaction: log sstable origin
sstables: scylla_metadata: add support for sstable_origin
sstables: sstable_writer_config: add origin member
After the switch from BST to B-tree the memory foorprint includes inner/leaf nodes
from the B-tree, so it's useful to know their sizes too.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The switch is pretty straightforward, and consists of
- change less-compare into tri-compare
- rename insert/insert_check into insert_before_hint
- use tree::key_grabber in mutation_partition::apply_monotonically to
exception-safely transfer a row from one tree to another
- explicitly erase the row from tree in rows_entry::on_evicted, there's
a O(1) tree::iterator method for this
- rewrite rows_entry -> cache_entry transofrmation in the on_evicted to
fit the B-tree API
- include the B-tree's external memory usage into stats
That's it. The number of keys per node was is set to 12 with linear search
and linear extention of 20 because
- experimenting with tree shows that numbers 8 through 10 keys with linear
search show the best performance on stress tests for insert/find-s of
keys that are memcmp-able arrays of bytes (which is an approximation of
current clustring key compare). More keys work slower, but still better
than any bigger value with any type of search up to 64 keys per node
- having 12 keys per nodes is the threshold at which the memory footprint
for B-tree becomes smaller than for boost::intrusive::set for partitions
with 32+ keys
- 20 keys for linear root eats the first-split peak and still performs
well in linear search
As a result the footpring for B tree is bigger than the one for BST only for
trees filled with 21...32 keys by 0.1...0.7 bytes per key.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The design of the tree goes from the row-cache needs, which are
1. Insert/Remove do not invalidate iterators
2. Elements are LSA-manageable
3. Low key overhead
4. External tri-comparator
5. As little actions on insert/remove as possible
With the above the design is
Two types of nodes -- inner and leaf. Both types keep pointer on parent nodes
and N pointers on keys (not keys themselves). Two differences: inner nodes have
array of pointers on kids, leaf nodes keep pointer on the tree (to update left-
and rightmost tree pointers on node move).
Nodes do not keep pointers/references on trees, thus we have O(1) move of any
object, but O(logN) to get the tree size. Fortunately, with big keys-per-node
value this won't result in too many steps.
In turn, the tree has 3 pointers -- root, left- and rightmost leaves. The latter
is for constant-time begin() and end().
Keys are managed by user with the help of embeddable member_hook instance,
which is 1 pointer in size.
The code was copied from the B+ tree one, then heavily reworked, the internal
algorythms turned out to differ quite significantly.
For the sake of mutation_partition::apply_monotonically(), which needs to move
an element from one tree into another, there's a key_grabber helping wrapper
that allows doing this move respecting the exception-safety requirement.
As measured by the perf_collections test the B-tree with 8 keys is faster, than
the std::set, but slower than the B+tree:
vs set vs b+tree
fill: +13% -6%
find: +23% -35%
Another neat thing is that 1-key insertion-removal is ~40% faster than
for BST (the same number of allocations, but the key object is smaller,
less pointers to set-up and less instructions to execute when linking
node with root).
v4:
- equip insertion methods with on_alloc_point() calls to catch
potential exception guarantees violations eariler
- add unlink_leftmost_without_rebalance. The method is borrowed from
boost intrusive set, and is added to kill two birds -- provide it,
as it turns out to be popular, and use a bit faster step-by-step
tree destruction than plain begin+erase loop
v3:
- introduce "inline" root node that is embedded into tree object and in
which the 1st key is inserted. This greatly improves the 1-key-tree
performance, which is pretty common case for rows cache
v2:
- introduce "linear" root leaf that grows on demand
This improves the memory consumption for small trees. This linear node may
and should over-grow the NodeSize parameter. This comes from the fact that
there are two big per-key memory spikes on small trees -- 1-key root leaf
and the first split, when the tree becomes 1-key root with two half-filled
leaves. If the linear extention goes above NodeSize it can flatten even the
2nd peak
- mitigate the keys indirection a bit
Prefetching the keys while doing the intra-node linear scan and the nodes
while descending the tree gives ~+5% of fill and find
- generalize stress tests for B and B+ trees
- cosmetic changes
TODO:
- fix few inefficincies in the core code (walks the sub-tree twice sometimes)
- try to optimize the leaf nodes, that are not lef-/righmost not to carry
unused tree pointer on board
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
clustering_range_walker detects when we jump from one row range to another. When
a static row is included in the query, the constructor sets up the first before/after
bounds to be exactly that static row. That creates an artificial range crossing if
the first clustering range is contiguous with the static row.
This can cause the index to be consulted needlessly if we happen to fall back
to sstable_mutation_reader after reading the static row.
A unit test is added.
Ref #7883.
Support configuration changes based on joint consensus.
When a user adds a configuration entry, commit an interim "joint
consensus" configuration to the log first, and transition to the
final configuration once both C_old and C_new configurations
accept the joint entry.
Misc cleanups.
* scylla-dev/raft-config-changes-v2:
raft: update README.md
raft: add a simple test for configuration changes
raft: joint consensus, wire up configuration changes in the API
raft: joint consensus, count votes using joint config
raft: joint consensus, wire up configuration changes in FSM
raft: joint consensus, update progress tracker with joint configuration
raft: joint consensus, don't store configuration in FSM
raft: joint consensus, keep track of the last confchange index in the log
raft: joint consensus, implement helpers in class configuration
raft: joint consensus, use unordered_set for server_address list
raft: joint consensus, switch configuration to joint
raft: rename check_committed() to maybe_commit()
raft: fix spelling and add comments
Add new scylla_metadata_type::SSTableOrigin.
Store and retrive a sstring to the scylla metadata component.
Pass sstable_writer_config::origin from the mx sstable writer
and ignore it in the k_l writer.
Add unit test to verify the sstable_origin extension
using both empty and a random string.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Add a string describing where the sstables originated
from (e.g. memtable, repair, streaming, compaction, etc.)
If configure_writer is called with a nullptr, the origin
will be equal to an empty string.
Introduce test_env_sstables_manager that provides an overload
of configure_writer with no parmeters that calls the base-class'
configure_writer with "test" origin. This was to reduce the
code churn in this patch and to keep the tests simple.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This patch adds a test for the different units which are supposed to
be usable for assigning a "duration" type in CQL. It turns out that
all documented units are supported correctly except µs (with a unicode
mu), so the test reproduces issue #8001.
The test xfails on Scylla (because µs is not supported) and passes
on Cassandra.
Refs: #8001.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210131192220.407481-1-nyh@scylladb.com>
In order to work correctly in transitional configuration,
participants must enter it after crashes, restarts and
state changes.
This means it must be stored in Raft log and snapshot
on the leader and followers.
This is most easily done if transitional configuration
is just a flavour of standard configuration.
In FSM, rename _current_config to _configuration,
it now contains both current and future configuration
at all times.
The idea of the monotonicity checking test is: try to apply
one one random partition to another random one sequentually
failing allocations. Each time allocation fails (with the
bad_alloc exception) -- check the exception guarantee is
respected, then apply (!) the very same two partitions to
each other. At the end of the test we make sure, that an
exception may pop up at any point of application and it
will be safe.
This idea is flawed currently. When verifying the guarantee
the test moves the 2nd partition and leaves it empty for the
next loop iteration. So right on the 2nd attempt to apply
partitions it becomes a no-op, doesn't fail and no more
exceptions arise.
Fix by restoring both partitions at the end of each check.
Broken since 74db08165d.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210129153641.5449-1-xemul@scylladb.com>
This series contains an initial implementation of raft persistency module
that uses `raft` system table as the underlying storage model.
"system.raft" table will be used as a backend storage for implementing
raft persistence module in Scylla. It combines both raft log,
persisted vote and term, and snapshot info.
The table is partitioned by group id, thus allowing multi-raft
operation. The rest of the table structure mirrors the fields of
corresponding core raft structures defined in `raft.hh`, such as
`raft::log_entry`.
The raft table stores the only the latest snapshot id while
the actual snapshot will be available in a separate table
called `system.raft_snapshots`. The schema of `raft_snapshots`
mirrors the fields of `raft::snapshot` structure.
IDL definitions are also added for every raft struct so that we
automatically provide serialization and deserialization facilities
needed both for persistency module and for future RPC implmementation.
The first patch is a side-change needed to provide complete
serialization/deserialization for `bytes_ostream`, which we
need when persisting the raft log in the table (since `data`
is a variant containing `raft::command` (aka `bytes_ostream`)
among others).
`bytes_ostream` was lacking `deserialize` function, which is
added in the patch.
The second patch provides serializer for `lw_shared_ptr<T>`
which will be used for `raft::append_entries`, which has
a field with `std::vector<const lw_shared_ptr<raft::log_entry>>`
type.
There is also a patch to extend `fragmented_temporary_buffer`
with a static function `allocate_to_fit` that allocates an
instance of the fragmented buffer that has a specified size.
Individual fragment size is limited to 128kb.
The patch-set also contains the test suite covering basic
functionality of the persistency module.
* manmanson/raft-api-impl-v11:
raft/sys_table_storage: add basic tests for raft_sys_table_storage
raft: introduce `raft_sys_table_storage` class
utils: add `fragmented_temporary_buffer::allocate_to_fit`
raft: add IDL definitions for raft types
raft: create `system.raft` and `system.raft_snapshots` tables
serializer: add `serializer<lw_shared_ptr<T>>` specialization
serializer: add `deserialize` function overload for `bytes_ostream`
The test suite covers the most basic use cases for the system table
backed raft persistency module:
* store/load vote and term
* store/load snapshot
* store snapshot with log tail truncation
* store/load log entries
* log truncation
Tests: unit(dev)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
We use a custom sharder for all schema tables: every table under
the `system_schema` keyspace, plus `system.scylla_table_schema_history`.
This sharder puts all data on shard 0.
To achieve this, we hardcode the sharder in initial schema object
definitions. Furthermore - since the sharder is not stored inside schema
mutations yet - whenever we deserialize schema objects from mutations,
we modify the sharder based on the schema's keyspace and table names.
A regression test is added to ensure no one forgets to set the special
sharder for newly added schema tables. This test assumes that all newly
added schema tables will end up in the `system_schema` keyspace (other
tables may go unnoticed, unfortunately).
Closes#7947
"
Currently there are three different methods for creating an sstable
reader:
* one for single key reads
* one for ranged reads
* and one nobody uses
This patch-set consolidates all these into a single `make_reader()`
method, which behind the scenes uses the same logic to dispatch to the
right sstable reader constructor that `sstables::as_mutation_source()`
uses.
This patch-set is part of an effort to clean up the jungle that is the
various reader creation methods. The next step is to clean up the
sstable_set, which has even more methods.
One very sad discovery I made while working on this patch-set is that
we
still default `mutation_reader::forwarding` to `yes` in the sstable
range reader creator method and in the
`mutation_source::make_reader()`.
I couldn't assume that all callers are passing what they mean as the
value for that parameter. I found many sites in tests that create
forwardable single partition readers. This is also something we should
address soon.
Tests: unit(release, debug:v3)
"
* 'sstables-consolidate-reader-factory-methods-v4' of https://github.com/denesb/scylla:
cql_query_test: add unit test covering the non-optimal TWCS sstable read path
sstable_mutation_reader: consolidate constructors
tests: don't pass temporary ranges to readers
sstables: sstable_mutation_reader: remove now unused whole sstable constructor
sstables: stats: remove now unused sstable_partition_reads counter
sstable: remove read_.*row.*_flat() methods
tree-wide: use sstables::make_reader() instead of the read_.*row.*_flat() methods
sstables: pass partition_range to create_single_key_sstable_reader()
sstables: sstable: add make_reader()
The sstable read path for TWCS tables takes a different path when the
optimized read path cannot be used. This path was found to be not
covered at all by unit tests which allowed a trivial use-after-free to
slip in. Add a unit test to cover this path as well, so ASAN can catch
such bugs in the future.
The sstable_mutation_reader, like all other mutation readers expects
that the partition-range passed to it is kept alive by its creator
for the duration of its lifetime. However, the single-key constructor
of the sstable reader was more tolerant, as it only extracted the key
from the range, essentially requiring only the key to be kept alive (but
not the containing range). Naturally in time some code come to rely on
it and ended up passing temporary ranges to the reader. This behaviour
will no longer be acceptable as we are about to consolidate the various
sstable reader constructors, uniformly requiring that the range is kept
alive. So this patch fixes up the tests so they work with this stricter
requirement. Only two occurences were found.
"
Currently we have two parallel query paths:
* database::query() -> table::query() -> data_query()
* mutation::query()
The former is used by single partition queries, the latter by range
scans, as mutation::query() is used to convert reconcilable_result to
query::result (which means it is also used in single partition queries
if it triggers read repair). This is a rather unfortunate situation as
we have two parallel implementation of the query code, which means they
are prone to diverge, and in fact they already have -- more on that
later.
This patchset aims to remedy this situation by retiring
`mutation::query()` and migrating users to an implementation based on
the "standard" query path, in other words one using the same building
blocks as the `database::query()` path. This means using
`compact_mutation` for compacting and `query_result_builder` for result
building. These components however were created to work with
`flat_mutation_reader`, however introducing a reader into this pipeline
would mean that we'd have to make all the related APIs asynchronous,
which would cause an insane amount of churn. To avoid this, this
patchset adds an API compatible `consume()` method to `mutation`, which
can accept a `compact_mutation` instance as-is. This allows an elegant
and succinct reimplementation. So far so good.
Like mentioned above, the two implementations have diverged in time, or
have been different from the start. The difference manifest when
calculating digests, more precisely in which tombstones are included in
the digest. The retired `mutation::query()` path incorporates only
non-purgeable tombstones in the digest. The standard query path however
incorporates all tombstones, even those that can be purged. After some
scrutiny however this difference proved to be completely theoretical,
as
the code path where this would matter -- converting reconcilable result
to query result -- passes min timestamp as the query time to the
compaction, so nothing is compacted and hence the difference has no
chance to manifest.
This patch-set was motivated by the desire to provide a single solution
to #7434, instead of two, one for each path.
Tests: unit(release:v2, debug:v2, dev:v3)
"
* 'unified-query-path/v3' of https://github.com/denesb/scylla:
mutation: remove now unused query() and query_compacted()
treewide: use query_mutations() instead of mutation::query()
mutation_test: test_query_digest: ensure digest is produced consistently
mutation_query: introduce query_mutation()
mutation_query: to_data_query_result(): migrate to standard query code
mutation_query: move to_data_query_result() to mutation_partition.cc
mutation: add consume()
flat_mutation_reader: move mutation consumer concepts to separate header
mutation compactor: query compaction: ignore purgeable tombstones
This patch adds a cql-pytest, test_json.py::test_tojson_double(),
which reproduces issue #7972 - where toJson() prints some doubles
incorrectly - truncated to integers, but some it prints fine (I
still don't know why, this will need to be debugged).
The test is marked xfail: It fails on Scylla, and passes on Cassandra.
Refs #7972.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210127124338.297544-1-nyh@scylladb.com>
The following patches fix issues seen occasionally in debug mode.
Notes:
- In debug mode there's still the UB nullptr arithmetic warning.
* https://github.com/alecco/scylla/tree/raft-ale-tests-07h-wait-propagation:
raft: replication test: wait for log propagation
raft: replication test: move wait for log to a function
raft: replication test: remove unused member
raft: replication test: use later()
raft: testing: remove election wait time and just yield
test_cell_external_memory_usage uses with_allocator() to observe how some
types allocate memory. However, compiler reordering (observed with clang 11
on aarch64) can move the various thread-local CQL type object initialization
into the with_allocator() scope; so any managed object allocated as part of
this initialization also gets measured, and the test fails. The code movement
is legal, as far as I can tell.
Fix this by initializing the type object early; use an atomic_thread_fence
as an optimization barrier so the compiler doesn't eliminate the or move
the early initialization.
Closes#7951
This patch adds a test for trying to set a tuple element to null with
fromJson(), which works on Cassandra but fails on Scylla. So the test
xfails on Scylla. Reproduces issue #7954.
Refs #7954.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210124082311.126300-1-nyh@scylladb.com>
If the message is larger than current buffer size, we need to consume
more data until we reach to tail of the message.
To do so, we need to return nullptr when it's not on the tail.
Fixes#7273
Wait until entries propagate after adding and before changing leader
using the same code as done for partitioning.
This fixes occasional hangs in debug mode when a test switches to a
different leader without leaving enough time for full propagation.
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Instead of sleep 1us use later()
Also use later to yield after sending append entries in rpc test impl.
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
If possible, test the highest sstable format version,
as it's the mostly used.
If there pre-written sstables we need to load from the
test directory from an older version, either specify their
version explicitly, or use the new test_env::reusable_sst
method that looks up the latest sstable version in the
given directory and generation.
Test: unit(release)
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20201210161822.2833510-1-bhalevy@scylladb.com>
The fromJson() function can take a map JSON and use it to set a map column.
However, the specific example of a map<ascii, int> doesn't work in Scylla
(it does work in Cassandra). The xfailing tests in this patch demonstrate
this. Although the tests use perfectly legal ASCII, scylla fails the
fromJson() function, with a misleading error.
Refs #7949.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210121233855.100640-1-nyh@scylladb.com>
Before we retire the mutation::query() code, expand the digest test to
check that the new code replacing it produces identical digest on all
possible equivalent mutations.
`multishard_combining_reader` currently only works under the assumption
that every table uses the same sharder configured using the node's number
of shards. But we could potentially specify a different sharder for a chosen table,
e.g. one that puts everything on shard 0.
Then this assumption will be broken and the reader causes a segfault.
Fixes#7945.
When writing to an integer column, Cassandra's fromJson() function allows
not just JSON number constants, it also allows a string containing a
number. Strings which do not hold a number fail with a FunctionFailure.
In particular, the empty string "" is an invalid number, and should fail.
The tests in this patch check this for two integer types: int and
varint.
Curiously, Cassandra and Scylla have opposite bugs here: Scylla fails
to recognize the error for varint, while Cassandra fails to recognize
the error for int. The tests in this patch reproduce these bugs.
The tests demonstrating Scylla's bug are marked xfail, and the tests
demonstrating Cassandra's bug is marked "cassandra_bug" (which means
it is marked xfail only when running against Cassandra, but expected
to succeed on Scylla.
Refs #7944.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210121133833.66075-1-nyh@scylladb.com>
