This warning prevents using std::move() where it can hurt
- on an unnamed temporary or a named automatic variable being
returned from a function. In both cases the value could be
constructed directly in its final destination, but std::move()
prevents it.
Fix the handful of cases (all trivial), and enable the warning.
Closes#8992
In order to avoid large allocations and too large mutations
generated from large view updates, granularity of the process
is broken down from per-partition to smaller chunks.
The view update builder now produces partial updates, no more
than 100 view rows at a time.
Previously the view update code generated a continuation for each
view update and stored them all in a vector. In certain cases
the number of updates can grow really large (to millions and beyond),
so it's better to only store a limited amount of these futures
at a time.
There were large allocation reportsa from vectors used for
calculating affected ranges. In order to reduce the pressure
on the allocator, chunked vector is used for storing intermediate
results.
The code was susceptible to use-after-move if both local
and remote updates were going to be sent.
The whole routine for sending view updates is now rewritten
to avoid use-after-move.
Refs #8830
Tests: unit(release),
dtest(secondary_indexes_test.py:TestSecondaryIndexes.test_remove_node_during_index_build)
The `apply_to_remote_endpoints` helper function used to take
its `mut` parameter by reference, but then moved the value from it,
which is confusing and prone to errors. Since the value is moved-from,
let's pass it to the helper function as rvalue ref explicitly.
The base token is passed cross-continuations, so the current way
of passing it by const reference probably only works because the token
copying is cheap enough to optimize the reference out.
Fix by explicitly taking the token by value.
The db::view code already uses proxy rather actively, so instead of
depending on the storage service to be at hands it's better to make
db::view require the proxy. For now -- via global instance.
There's one dependency on storage service left after this patch --
to get the tokens. This piece is to be fixed later.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
storage_proxy uses std::vector<inet_address> for small lists of nodes - for replication (often 2-3 replicas per operation) and for pending operations (usually 0-1). These vectors require an allocation, sometimes more than one if reserve() is not used correctly.
This series switches storage_proxy to use utils::small_vector instead, removing the allocations in the common case.
Test results (perf_simple_query --smp 1 --task-quota-ms 10):
```
before: median 184810.98 tps ( 91.1 allocs/op, 20.1 tasks/op, 54564 insns/op)
after: median 192125.99 tps ( 87.1 allocs/op, 20.1 tasks/op, 53673 insns/op)
```
4 allocations and ~900 instructions are removed (the tps figure is also improved, but it is less reliable due to cpu frequency changes).
The type change is unfortunately not contained in storage_proxy - the abstraction leaks to providers of replica sets and topology change vectors. This is sad but IMO the benefits make it worthwhile.
I expect more such changes can be applied in storage_proxy, specifically std::unordered_set<gms::inet_address> and vectors of response handles.
Closes#8592
* github.com:scylladb/scylla:
storage_proxy, treewide: use utils::small_vector inet_address_vector:s
storage_proxy, treewide: introduce names for vectors of inet_address
utils: small_vector: add print operator for std::ostream
hints: messages.hh: add missing #include
storage_proxy works with vectors of inet_addresses for replica sets
and for topology changes (pending endpoints, dead nodes). This patch
introduces new names for these (without changing the underlying
type - it's still std::vector<gms::inet_address>). This is so that
the following patch, that changes those types to utils::small_vector,
will be less noisy and highlight the real changes that take place.
Every time db/config.hh is modified (e.g., to add a new configuration
option), 110 source files need to be recompiled. Many of those 110 didn't
really care about configuration options, and just got the dependency
accidentally by including some other header file.
In this patch, I remove the include of "db/config.hh" from all header
files. It is only needed in source files - and header files only
need forward declarations. In some cases, source files were missing
certain includes which they got incidentally from db/config.hh, so I
had to add these includes explicitly.
After this patch, the number of source files that get recompiled after a
change to db/config.hh goes down from 110 to 45.
It also means that 65 source files now compile faster because they don't
include db/config.hh and whatever it included.
Additionally, this patch also eliminates a few unnecessary inclusions
of database.hh in other header files, which can use a forward declaration
or database_fwd.hh. Some of the source files including one of those
header files relied on one of the many header files brought in by
database.hh, so we need to include those explicitly.
In view_update_generator.hh something interesting happened - it *needs*
database.hh because of code in the header file, but only included
database_fwd.hh, and the only reason this worked was that the files
including view_update_generator.hh already happened to unnecessarily
include database.hh. So we fix that too.
Refs #1
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210505121830.964529-1-nyh@scylladb.com>
Every time db/config.hh is modified (e.g., to add a new configuration
option), 110 source files need to be recompiled. Many of those 110 didn't
really care about configuration options, and just got the dependency
accidentally by including some other header file.
In this patch, I remove the include of "db/config.hh" from all header
files. It is only needed in source files - and header files only
need forward declarations. In some cases, source files were missing
certain includes which they got incidentally from db/config.hh, so I
had to add these includes explicitly.
After this patch, the number of source files that get recompiled after a
change to db/config.hh goes down from 110 to 45.
It also means that 65 source files now compile faster because they don't
include db/config.hh and whatever it included.
Additionally, this patch also eliminates a few unnecessary inclusions
of database.hh in other header files, which can use a forward declaration
or database_fwd.hh. Some of the source files including one of those
header files relied on one of the many header files brought in by
database.hh, so we need to include those explicitly.
In view_update_generator.hh something interesting happened - it *needs*
database.hh because of code in the header file, but only included
database_fwd.hh, and the only reason this worked was that the files
including view_update_generator.hh already happened to unnecessarily
include database.hh. So we fix that too.
Refs #1
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210505102111.955470-1-nyh@scylladb.com>
Make sure to close the builder's _updates and optional _existings
readers before they are destroyed.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
storage_proxy.hh is huge and includes many headers itself, so
remove its inclusions from headers and re-add smaller headers
where needed (and storage_proxy.hh itself in source files that
need it).
Ref #1.
This just causes unneeded and slower recompliations. Instead replace
with forward declarations, or includes of smaller headers that were
incidentally brought in by the one removed. The .cc files that really
need it gain the include, but they are few.
Ref #1.
Closes#8403
Currently, the sstable_set in a table is copied before every change
to allow accessing the unchanged version by existing sstable readers.
This patch changes the sstable_set to a structure that keeps all its
versions that are referenced somewhere and provides a way of getting
a reference to an immutable version of the set.
Each sstable in the set is associated with the versions it is alive in,
and is removed when all such versions don't have references anymore.
To avoid copying, the object holding all sstables in the set version is
changed to a new structure, sstable_list, which was previously an alias
for std::unordered_set<shared_sstable>, and which implements most of the
methods of an unordered_set, but its iterator uses the actual set with
all sstables from all referenced versions and iterates over those
sstables that belong to the captured version.
The methods that modify the sets contents give strong exception guarantee
by trying to insert new sstables to its containers, and erasing them in
the case of an caught exception.
To release shared_sstables as soon as possible (i.e. when all references
to versions that contain them die), each time a version is removed, all
sstables that were referenced exclusively by this version are erased. We
are able to find these sstables efficiently by storing, for each version,
all sstables that were added and erased in it, and, when a version is
removed, merging it with the next one. When a version that adds an sstable
gets merged with a version that removes it, this sstable is erased.
Fixes#2622
Signed-off-by: Wojciech Mitros wojciech.mitros@scylladb.comCloses#8111
* github.com:scylladb/scylla:
sstables: add test for checking the latency of updating the sstable_set in a table
sstables: move column_family_test class from test/boost to test/lib
sstables: use fast copying of the sstable_set instead of rebuilding it
sstables: replace the sstable_set with a versioned structure
sstables: remove potential ub
sstables: make sstable_set constructor less error-prone
The error now contains information about the view table that failed,
as well as base and view tokens.
Example:
view - Error applying view update to 127.0.0.1 (view: ks.testme_v_idx_index,
base token: -4069959284402364209, view token: -3248873570005575792): std::runtime_error (manually injected error)
Fixes#8177Closes#8178
Commit aab6b0ee27 introduced the
controversial new IMR format, which relied on a very template-heavy
infrastructure to generate serialization and deserialization code via
template meta-programming. The promise was that this new format, beyond
solving the problems the previous open-coded representation had (working
on linearized buffers), will speed up migrating other components to this
IMR format, as the IMR infrastructure reduces code bloat, makes the code
more readable via declarative type descriptions as well as safer.
However, the results were almost the opposite. The template
meta-programming used by the IMR infrastructure proved very hard to
understand. Developers don't want to read or modify it. Maintainers
don't want to see it being used anywhere else. In short, nobody wants to
touch it.
This commit does a conceptual revert of
aab6b0ee27. A verbatim revert is not
possible because related code evolved a lot since the merge. Also, going
back to the previous code would mean we regress as we'd revert the move
to fragmented buffers. So this revert is only conceptual, it changes the
underlying infrastructure back to the previous open-coded one, but keeps
the fragmented buffers, as well as the interface of the related
components (to the extent possible).
Fixes: #5578
Adding an non-empty set of sstables as the set of all sstables in
an sstable_set could cause inconsistencies with the values returned
by select_sstable_runs because the _all_runs map would still be
initialized empty. For similar reasons, the provided sstable_set_impl
should also be empty.
Dispel doubts by removing the unordered_set from the constructor, and
adding a check of emptiness of the sstable_set_impl.
Signed-off-by: Wojciech Mitros <wojciech.mitros@scylladb.com>
The main motivation for this patchset is to prepare
for adding a async close() method to flat_mutation_reader.
In order to close the reader before destroying it
in all paths we need to make next_partition asynchronous
so it can asynchronously close a current reader before
destoring it, e.g. by reassignment of flat_mutation_reader_opt,
as done in scanning_reader::next_partition.
Test: unit(release, debug)
* git@github.com:bhalevy/scylla.git futurize-next-partition-v1:
flat_mutation_reader: return future from next_partition
multishard_mutation_query: read_context: save_reader: destroy reader_meta from the calling shard
mutation_reader: filtering_reader: fill_buffer: futurize inner loop
flat_mutation_reader::impl: consumer_adapter: futurize handle_result
flat_mutation_reader: consume_pausable/in_thread: futurize_invoke consumer
flat_mutation_reader: FlatMutationReaderConsumer: support also async consumer
flat_mutation_reader:impl: get rid of _consume_done member
The keys classes (partition_key et al) already use managed_bytes,
but they assume the data is not fragmented and make liberal use
of that by casting to bytes_view. The view classes use bytes_view.
Change that to managed_bytes_view, and adjust return values
to managed_bytes/managed_bytes_view.
The callers are adjusted. In some places linearization (to_bytes())
is needed, but this isn't too bad as keys are always <= 64k and thus
will not be fragmented when out of LSA. We can remove this
linearization later.
The serialize_value() template is called from a long chain, and
can be reached with either bytes_view or managed_bytes_view.
Rather than trace and adjust all the callers, we patch it now
with constexpr if.
operator bytes_view (in keys) is converted to operator
managed_bytes_view, allowing callers to defer or avoid
linearization.
This reverts commit dc77d128e9. It was reverted
due to a strange and unexplained diff, which is now explained. The
HEAD on the working directory being pulled from was set back, so git
thought it was merging the intended commits, plus all the work that was
committed from HEAD to master. So it is safe to restore it.
This reverts commit 0aa1f7c70a, reversing
changes made to 72c59e8000. The diff is
strange, including unrelated commits. There is no understanding of the
cause, so to be safe, revert and try again.
1. sstables: move `sstable_set` implementations to a separate module
All the implementations were kept in sstables/compaction_strategy.cc
which is quite large even without them. `sstable_set` already had its
own header file, now it gets its own implementation file.
The declarations of implementation classes and interfaces (`sstable_set_impl`,
`bag_sstable_set`, and so on) were also exposed in a header file,
sstable_set_impl.hh, for the purposes of potential unit testing.
2. mutation_reader: move `mutation_reader::forwarding` to flat_mutation_reader.hh
Files which need this definition won't have to include
mutation_reader.hh, only flat_mutation_reader.hh (so the inclusions are
in total smaller; mutation_reader.hh includes flat_mutation_reader.hh).
3. sstables: move sstable reader creation functions to `sstable_set`
Lower level functions such as `create_single_key_sstable_reader`
were made methods of `sstable_set`.
The motivation is that each concrete sstable_set
may decide to use a better sstable reading algorithm specific to the
data structures used by this sstable_set. For this it needs to access
the set's internals.
A nice side effect is that we moved some code out of table.cc
and database.hh which are huge files.
4. sstables: pass `ring_position` to `create_single_key_sstable_reader`
instead of `partition_range`.
It would be best to pass `partition_key` or `decorated_key` here.
However, the implementation of this function needs a `partition_range`
to pass into `sstable_set::select`, and `partition_range` must be
constructed from `ring_position`s. We could create the `ring_position`
internally from the key but that would involve a copy which we want to
avoid.
5. sstable_set: refactor `filter_sstable_for_reader_by_pk`
Introduce a `make_pk_filter` function, which given a ring position,
returns a boolean function (a filter) that given a sstable, tells
whether the sstable may contain rows with the given position.
The logic has been extracted from `filter_sstable_for_reader_by_pk`.
Split from #7437.
Closes#7655
* github.com:scylladb/scylla:
sstable_set: refactor filter_sstable_for_reader_by_pk
sstables: pass ring_position to create_single_key_sstable_reader
sstables: move sstable reader creation functions to `sstable_set`
mutation_reader: move mutation_reader::forwarding to flat_mutation_reader.hh
sstables: move sstable_set implementations to a separate module
Lower level functions such as `create_single_key_sstable_reader`
were made methods of `sstable_set`.
The motivation is that each concrete sstable_set
may decide to use a better sstable reading algorithm specific to the
data structures used by this sstable_set. For this it needs to access
the set's internals.
A nice side effect is that we moved some code out of table.cc
and database.hh which are huge files.
If a list of target endpoints for sending view updates contains
duplicates, it results in benign (but annoying) broken promise
errors happening due to duplicated write response handlers being
instantiated for a single endpoint.
In order to avoid such errors, target remote endpoints are deduplicated
from the list of pending endpoints.
A similar issue (#5459) solved the case for duplicated local endpoints,
but that didn't solve the general case.
Fixes#7572Closes#7641
When a missing base column happens to be named `idx_token`,
an additional helper message is printed in logs.
This additional message does not need to have `error` severity,
since the previous, generic message is already marked as `error`.
This patch simply makes it easier to write tests, because in case
this error is expected, only one message needs to be explicitly
ignored instead of two.
Closes#7597
Raname token_column_computation to legacy_token_column_computation, as
it will be replaced with new column_computation. The reason is that this
computation returns bytes, but all tokens in Scylla can now be
represented by int64_t. Moreover, returning bytes causes invalid token
ordering as bytes comparison is done in unsigned way (not signed as
int64_t). See issue:
https://github.com/scylladb/scylla/issues/7443
When an out-of-sync view is attempted to be used in a write operation,
the whole operation needs to be aborted with an error. After this patch,
the error contains more context - namely, the missing column.
The code which created base-dependent info for materialized views
can be expressed with fewer branches. Also, the constructor
which takes a single parameter is made explicit.
When Scylla finds out that a materialized view contains columns
which are not present in the base table (and they are not computed),
it now presents comprehensible errors in the log.
only reading from view.
The current implementation of materialized views does
no keep the version to which a specific version of materialized
view schema corresponds to. This complicate things especially on
old views versions that the schema doesn't support anymore. However,
the views, being also an independent table should allow reading from
them as long as they exist even if the base table changed since then.
For the reading purpose, we don't need to know the exact composition
of view primary key columns that are not part of the base primary
key, we only need to know that there are any, and this is a much
looser constrain on the schema.
We can rely on a table invariants such as the fact that pk columns are
not going to disappear on newer version of the table.
This means that if we don't find a view column in the base table, it is
not a part of the base table primary key.
This information is enough for us to perform read on the view.
This commit adds support for being able to rely on such partial
information along with a validation that it is not going to be used for
writes. If it is, we simply abort since this means that our schema
integrity is compromised.
