"
Incremental compaction code to release exhausted sstables was inefficient because
it was basically preventing any release from ever happening. So a new solution is
implemented to make incremental compaction approach actually efficient while
being cautious about not introducing data resurrection. This solution consists of
storing GC'able tombstones in a temporary sstable and keeping it till the end of
compaction. Overhead is avoided by not enabling it to strategies that don't work
with runs composed of multiple fragments.
Fixes#4531.
tests: unit, longevity 1TB for incremental compaction
"
* 'fix_incremental_compaction_efficiency/v6' of https://github.com/raphaelsc/scylla:
tests: Check that partition is not resurrected on compaction failure
tests: Add sstable compaction test for gc-only mutation compactor consumer
sstables: Fix Incremental Compaction Efficiency
Allow returning fewer random clustering keys than requested since
the schema may limit the total number we can generate, for example,
if there is only one boolean clustering column.
Fixes#5161
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Make sure gc'able-tombstone-only sstable is properly generated with data that
comes from regular compaction's input sstable.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Compaction prevents data resurrection from happening by checking that there's
no way a data shadowed by a GC'able tombstone will survive alone, after
a failure for example.
Consider the following scenario:
We have two runs A and B, each divided to 5 fragments, A1..A5, B1..B5.
They have the following token ranges:
A: A1=[0, 3] A2=[4, 7] A3=[8, 11] A4=[12, 15] A5=[16,18]
B is the same as A's ranges, offset by 1:
B: B1=[1,4] B2=[5,8] B3=[9,12] B4=[13,16] B5=[17,19]
Let's say we are finished flushing output until position 10 in the compaction.
We are currently working on A3 and B3, so obviously those cannot be deleted.
Because B2 overlaps with A3, we cannot delete B2 either.
Otherwise, B2 could have a GC'able tombstone that shadows data in A3, and after
B2 is gone, dead data in A3 could be resurrected *on failure*.
Now, A2 overlaps with B2 which we couldn't delete yet, so we can't delete A2.
Now A2 overlaps with B1 so we can't delete B1. And B1 overlaps with A1 so
we can't delete A1. So we can't delete any fragment.
The problem with this approach is obvious, fragments can potentially not be
released due to data dependency, so incremental compaction efficiency is
severely reduced.
To fix it, let's not purge GC'able tombstones right away in the mutation
compactor step. Instead, let's have compaction writing them to a separate
sstable run that would be deleted in the end of compaction.
By making sure that tombstone information from all compacting sstables is not
lost, we no longer need to have incremental compaction imposing lots of
restriction on which fragments could be released. Now, any sstable which data
is safe in a new sstable can be released right away. In addition, incremental
compaction will only take place if compaction procedure is working with one
multi-fragment sstable run at least.
Fixes#4531.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
* seastar 1f68be436f...e888b1df9c (8):
> sharded: Make map work with mapper that returns a future
> cmake: Remove FindBoost.cmake
> Reduce noncopyable_function instruction cache footprint
> doc: add Loops section to the tutorial
> Merge "Move file related code out of reactor" from Asias
> Merge "Move the io_queue code out of reactor" from Asias
> cmake: expose seastar_perf_testing lib
> future: class doc: explain why discarding a future is bad
- main.cc now includes new file io_queue.hh
- perf tests now include seastar perf utilities via user, not
system, includes since those are not exported
"
Fixes#5134, Eviction concurrent with preempted partition entry update after
memtable flush may allow stale data to be populated into cache.
Fixes#5135, Cache reads may miss some writes if schema alter followed by a
read happened concurrently with preempted partition entry update.
Fixes#5127, Cache populating read concurrent with schema alter may use the
wrong schema version to interpret sstable data.
Fixes#5128, Reads of multi-row partitions concurrent with memtable flush may
fail or cause a node crash after schema alter.
"
* tag 'fix-cache-issues-with-schema-alter-and-eviction-v2' of github.com:tgrabiec/scylla:
tests: row_cache: Introduce test_alter_then_preempted_update_then_memtable_read
tests: row_cache_stress_test: Verify all entries are evictable at the end
tests: row_cache_stress_test: Exercise single-partition reads
tests: row_cache_stress_test: Add periodic schema alters
tests: memtable_snapshot_source: Allow changing the schema
tests: simple_schema: Prepare for schema altering
row_cache: Record upgraded schema in memtable entries during update
memtable: Extract memtable_entry::upgrade_schema()
row_cache, mvcc: Prevent locked snapshots from being evicted
row_cache: Make evict() not use invalidate_unwrapped()
mvcc: Introduce partition_snapshot::touch()
row_cache, mvcc: Do not upgrade schema of entries which are being updated
row_cache: Use the correct schema version to populate the partition entry
delegating_reader: Optimize fill_buffer()
row_cache, memtable: Use upgrade_schema()
flat_mutation_reader: Introduce upgrade_schema()
make_single_key_reader() currently doesn't actually create
single-partition readers because it doesn't set
mutation_reader::forwarding::no when it creates individual
readers. The readers will default to mutation_reader::forwarding::yes
and actually create scanning readers in preparation for
fast-forwarding across partitions.
Fix by passing mutation_reader::forwarding::no.
Currently, methods of simple_schema assume that table's schema doesn't
change. Accessors like get_value() assume that rows were generated
using simple_schema::_s. Because if that, the column_definition& for
the "v" column is cached in the instance. That column_definiion&
cannot be used to access objects created with a different schema
version. To allow using simple_schema after schema changes,
column_definition& caching is now tagged with the table schema version
of origin. Methods which access schema-dependent objects, like
get_value(), are now accepting schema& corresponding to the objects.
Also, it's now possible to tell simple_schema to use a different
schema version in its generator methods.
Cache update may defer in the middle of moving of partition entry
from a flushed memtable to the cache. If the schema was changed since
the entry was written, it upgrades the schema of the partition_entry
first but doesn't update the schema_ptr in memtable_entry. The entry
is removed from the memtable afterward. If a memtable reader
encounters such an entry, it will try to upgrade it assuming it's
still at the old schema.
That is undefined behavior in general, which may include:
- read failures due to bad_alloc, if fixed-size cells are interpreted
as variable-sized cells, and we misinterpret a value for a huge
size
- wrong read results
- node crash
This doesn't result in a permanent corruption, restarting the node
should help.
It's the more likely to happen the more rows there are in a
partition. It's unlikely to happen with single-row partitions.
Introduced in 70c7277.
Fixes#5128.
Frozen empty lists/map/sets are not equal to null value,
whil multi-cell empty lists/map/sets are equal to null values.
Return a NULL value for an empty multi-cell set or list
if we know the receiver is not frozen - this makes it
easy to compare the parameter with the receiver.
Add a test case for inserting an empty list or set
- the result is indistinguishable from NULL value.
Message-Id: <20191003092157.92294-2-kostja@scylladb.com>
"
This is the second version of the patch series. The previous one was just the second patch, this one adds more tests an another patch to make it easier to test that the new code has the same behavior as the old one.
"
* 'espindola/overflow-is-intentional' of https://github.com/espindola/scylla:
types: Simplify and explain from_varint_to_integer
Add more cast tests
The method sstable::estimated_keys_for_range() was severely
under-estimating the number of partitions in an sstable for a given
token range.
The first reason is that it underestimated the number of sstable index
pages covered by the range, by one. In extreme, if the requested range
falls into a single index page, we will assume 0 pages, and report 1
partition. The reason is that we were using
get_sample_indexes_for_range(), which returns entries with the keys
falling into the range, not entries for pages which may contain the
keys.
A single page can have a lot of partitions though. By default, there
is a 1:20000 ratio between summary entry size and the data file size
covered by it. If partitions are small, that can be many hundreds of
partitions.
Another reason is that we underestimate the number of partitions in an
index page. We multiply the number of pages by:
(downsampling::BASE_SAMPLING_LEVEL * _components->summary.header.min_index_interval)
/ _components->summary.header.sampling_level
Using defaults, that means multiplying by 128. In the cassandra-stress
workload a single partition takes about 300 bytes in the data file and
summary entry is 22 bytes. That means a single page covers 22 * 20'000
= 440'000 bytes of the data file, which contains about 1'466
partitions. So we underestimate by an order of magnitude.
Underestimating the number of partitions will result in too small
bloom filters being generated for the sstables which are the output of
repair or streaming. This will make the bloom filters ineffective
which results in reads selecting more sstables than necessary.
The fix is to base the estimation on the number of index pages which
may contain keys for the range, and multiply that by the average key
count per index page.
Fixes#5112.
Refs #4994.
The output of test_key_count_estimation:
Before:
count = 10000
est = 10112
est([-inf; +inf]) = 512
est([0; 0]) = 128
est([0; 63]) = 128
est([0; 255]) = 128
est([0; 511]) = 128
est([0; 1023]) = 128
est([0; 4095]) = 256
est([0; 9999]) = 512
est([5000; 5000]) = 1
est([5000; 5063]) = 1
est([5000; 5255]) = 1
est([5000; 5511]) = 1
est([5000; 6023]) = 128
est([5000; 9095]) = 256
est([5000; 9999]) = 256
est(non-overlapping to the left) = 1
est(non-overlapping to the right) = 1
After:
count = 10000
est = 10112
est([-inf; +inf]) = 10112
est([0; 0]) = 2528
est([0; 63]) = 2528
est([0; 255]) = 2528
est([0; 511]) = 2528
est([0; 1023]) = 2528
est([0; 4095]) = 5056
est([0; 9999]) = 10112
est([5000; 5000]) = 2528
est([5000; 5063]) = 2528
est([5000; 5255]) = 2528
est([5000; 5511]) = 2528
est([5000; 6023]) = 5056
est([5000; 9095]) = 7584
est([5000; 9999]) = 7584
est(non-overlapping to the left) = 0
est(non-overlapping to the right) = 0
Tests:
- unit (dev)
Reviewed-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20190927141339.31315-1-tgrabiec@scylladb.com>
When the toppartitions operation gathers results, it copies partition
keys with their schema_ptr:s. When these schema_ptr:s are copies
or destroyed, they can cause leaks or premature frees of the schema
in its original shard since reference count operations in are not atomic.
Fix that by converting the schema_ptr to a global_schema_ptr during
transportation.
Fixes#5104 (direct bug)
Fixes#5018 (schema prematurely freed, toppartitions previously executed on that node)
Fixes#4973 (corrupted memory pool of the same size class as schema, toppartitions previously executed on that node)
Tests: new test added that fails with the existing code in debug mode,
manual toppartitions test
In the system.types table a user type refers to another by name. When
a user type is modified, only its entry in the table is changed.
At runtime a user type has direct pointer to the types it uses. To
handle the discrepancy we need to recreate any dependent types when a
entry in system.types changes.
Fixes#5049
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Before this patch, if the _gate is closed, with_gate throws and
forward_to is not executed. When the promise<> p is destroyed it marks
its _task as a broken promise.
What happens next depends on the branch.
On master, we warn when the shared_future is destroyed, so this patch
changes the warning from a broken_promise to a gate closed.
On 3.1, we warn when the promises in shared_future::_peers are
destroyed since they no longer have a future attached: The future that
was attached was the "auto f" just before the with_gate call, and it
is destroyed when with_gate throws. The net result is that this patch
fixes the warning in 3.1.
I will send a patch to seastar to make the warning on master more
consistent with the warning in 3.1.
Fixes#4394
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20190917211915.117252-1-espindola@scylladb.com>
If the user supplies the 'replication_factor' to the 'NetworkTopologyStrategy' class,
it will expand into a replication factor for each existing DC for their convenience.
Resolves#4210.
Signed-off-by: Kamil Braun <kbraun@scylladb.com>
Introduce mutation_fragment_stream_validator class and use it as a
Filter to flat_mutation_reader::consume_in_thread from
sstable::write_components to validate partition region and optionally
clustering key monotonicity.
Fixes#4803
"
The release notes for boost 1.67.0 includes:
Breaking Change: When converting a multiprecision integer to a narrower type, if the value is too large (or negative) to fit in the smaller type, then the result is either the maximum (or minimum) value of the target
Since we just moved out of boost 1.66, we have to update our code.
This fixes issue #4960
"
* 'espindola/fix-4960' of https://github.com/espindola/scylla:
types: fix varint to integer conversion
types: extract a from_varint_to_integer from make_castas_fctn_from_decimal_to_integer
types: fix decimal to integer conversion
types: extract helper for converting a decimal to a cppint
types: rename and detemplate make_castas_fctn_from_decimal_to_integer
In these cases it is pretty clear that the original code wanted to
create a timestamp_type data_value but was creating a date_type one
because of the old defaults.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Now that we know that anything expecting a date_type has been
converted to date_type_native_type, switch to using
db_clock::time_point when we want a timestamp_type.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
date_type was replaced with timestamp_type, but it was very easy to
create a date_type instead of a timestamp_type by accident.
This patch changes the code so that a date_type is no longer
implicitly used when constructing a data_value. All existing code that
was depending on this is converted to explicitly using
date_type_native_type. A followup patch will convert to timestamp_type
when appropriate.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Commit 7e3805ed3d removed the load balancing code from cql
server, but it did not remove most of the craft that load balancing
introduced. The most of the complexity (and probably the main reason the
code never worked properly) is around service::client_state class which
is copied before been passed to the request processor (because in the past
the processing could have happened on another shard) and then merged back
into the "master copy" because a request processing may have changed it.
This commit remove all this copying. The client_request is passed as a
reference all the way to the lowest layer that needs it and it copy
construction is removed to make sure nobody copies it by mistake.
tests: dev, default c-s load of 3 node cluster
Message-Id: <20190906083050.GA21796@scylladb.com>
The previous code was using the boost::multiprecision::cpp_int to
integer conversion, but that doesn't have the same semantics an cql
for signed numbers.
This fixes the dtest cql_cast_test.py:CQLCastTest.cast_varint_test.
Fixes#4960
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
The previous code was using the boost::multiprecision::cpp_rational to
integer conversion, but that doesn't have the same semantics an cql.
This patch avoids creating a cpp_rational in the first place and works
just with integers.
This fixes the dtest cql_cast_test.py:CQLCastTest.cast_decimal_test.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Some tests are currently discarding futures unjustifiably, however
adding code to wait on these futures is quite inconvenient due to the
continuation style code of these tests. Convert them to run in a seastar
thread to make the fix easier.
Cartesian products (via IN restrictions) make it easy to generate huge
primary key sets with simple queries, overflowing server resources. Limit
them in the coordinator and report an exception instead of trying to
execute a query that would consume all of our memory.
A unit test is added.
We need a way to configure the cql interpreter and runtime. So far we relied
on accessing the configuration class via various backdoors, but that causes
its own problems around initialization order and testability. To avoid that,
this patch adds an empty cql_config class and propagates it from main.cc
(and from tests) to the cql interpreter via the query_options class, which is
already passed everywhere.
Later patches will fill it with contents.
This was broken since the type refactoring. It was checking the static
type, which is always abstract_type. Unfortunately we only had dtests
for this.
This can probably be optimized to avoid the double switch over kind,
but it is probably better to do the simple fix first.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20190821155354.47704-1-espindola@scylladb.com>
Currently we create a regex from the LIKE pattern for every row
considered during filtering, even though the pattern is always the
same. This is wasteful, especially since we require costly
optimization in the regex compiler. Fix it by reusing the regex
whenever the pattern is unchanged since the last call.
Tests: unit (dev)
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Non-full prefix keys are currently not handled correctly as all keys
are treated as if they were full prefixes, and therefore they represent
a point in the key space. Non-full prefixes however represent a
sub-range of the key space and therefore require null extending before
they can be treated as a point.
As a quick reminder, `key` is used to trim the clustering ranges such
that they only cover positions >= then key. Thus,
`trim_clustering_row_ranges_to()` does the equivalent of intersecting
each range with (key, inf). When `key` is a prefix, this would exclude
all positions that are prefixed by key as well, which is not desired.
Fixes: #4839
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20190819134950.33406-1-bdenes@scylladb.com>
"
Follow-up to #4610, where a review comment asked for test coverage on all types. Existing tests cover all the types admissible in LIKE, while this PR adds coverage for all inadmissible types.
Tests: unit (dev)
"
* 'like-nonstring' of https://github.com/dekimir/scylla:
cql_query_test: Add LIKE tests for all types
cql_query_test: Remove LIKE-nonstring-pattern case
cql_query_test: Move a testcase elsewhere in file
In b197924, we changed the shutdown process not to rely on the global
reactor-defined exit, but instead added a local variable to hold the
shutdown state. However, we did not propagate that state everywhere,
and now streaming processes are not able to abort.
Fix that by enhancing stop_signal with a sharded<abort_source> member
that can be propagated to services. Propagate it to storage_service
and thence to boot_strapper and range_streamer so that streaming
processes can be aborted.
Fixes#4674Fixes#4501
Tests: unit (dev), manual bootstrap test
Propagate the abort_source from main() into boot_strapper and range_stream and
check for aborts at strategic points. This includes aborting running stream_plans
and aborting sleeps between retries.
Fixes#4674
"
This is hopefully the last large refactoring on the way of UDF.
In UDF we have to convert internal types to Lua and back. Currently
almost all our types and hidden in types.cc and expose functionality
via virtual functions. While it should be possible to add a
convert_{to|from}_lua virtual functions, that seems like a bad design.
In compilers, the type definition is normally public and different
passes know how to reason about each type. The alias analysis knows
about int and floats, not the other way around.
This patch series is inspired by both the LLVM RTTI
(https://www.llvm.org/docs/HowToSetUpLLVMStyleRTTI.html) and
std::variant.
The series makes the types public, adds a visit function and converts
the various virtual methods to just use visit. As a small example of
why this is useful, it then moves a bit of cql3 and json specific
logic out of types.cc and types.hh. In a similar way, the UDF code
will be able to used visit to convert objects to Lua.
In comparison with the previous versions, this series doesn't require the intermediate step of converting void* to data_value& in a few member functions.
This version also has fewer double dispatches I a am fairly confident has all the tools for avoiding all double dispatches.
"
* 'simplify-types-v3' of https://github.com/espindola/scylla: (80 commits)
types: Move abstract_type visit to a header
types: Move uuid_type_impl to a header
types: Move inet_addr_type_impl to a header
types: Move varint_type_impl to a header
types: Move timeuuid_type_impl to a header
types: Move date_type_impl to a header
types: Move bytes_type_impl to a header
types: Move utf8_type_impl to a header
types: Move ascii_type_impl to a header
types: Move string_type_impl to a header
types: Move time_type_impl to a header
types: Move simple_date_type_impl to a header
types: Move timestamp_type_impl to a header
types: Move duration_type_impl to a header
types: Move decimal_type_impl to a header
types: Move floating point types to a header
types: Move boolean_type_impl to a header
types: Move integer types to a header
types: Move integer_type_impl to a header
types: Move simple_type_impl to a header
...
