We introduce a new single-key sstable reader for sstables created by `TimeWindowCompactionStrategy`.
The reader uses the fact that sstables created by TWCS are mostly disjoint with respect to the contained `position_in_partition`s in order to avoid having multiple sstable readers opened at the same time unnecessarily. In case there are overlapping ranges (for example, in the current time-window), it performs the necessary merging (it uses `clustering_order_reader_merger`, introduced recently).
The reader uses min/max clustering key metadata present in `md` sstables in order to decide when to open or close a sstable reader.
The following experiment was performed:
1. create a TWCS table with 1 minute windows
2. fill the table with 8 equal windows of data
(each window flushed to a separate sstable)
3. perform `select * from ks.t where pk = 0 limit 1` query
with and without the change
The expectation is that with the commit, only one sstable will be opened
to fetch that one row; without the commit all 8 sstables would be opened at once.
The difference in the value of `scylla_reactor_aio_bytes_read` was measured
(value after the query minus value before the query), both with and without the commit.
With the commit, the difference was 67584.
Without the commit, the difference was 528384.
528384 / 67584 ~= 7.8.
Fixes#6418.
Closes#7437
* github.com:scylladb/scylla:
sstables: gather clustering key filtering statistics in TWCS single key reader
sstables: use time_series_sstable_set in time_window_compaction_strategy
sstable_set: new reader for TWCS single partition queries
mutation_reader_test: test clustering_order_reader_merger with time_series_sstable_set
sstable_set: introduce min_position_reader_queue
sstable_set: introduce time_series_sstable_set
sstables: add min_position and max_position accessors
sstable_set: make create_single_key_sstable_reader a virtual method
clustering_order_reader_merger: fix the 0 readers case
There were two problems with handling conflicting equalities on the same PK column (eg, c=1 AND c=0):
1. When the column is indexed, Scylla crashed (#7772)
2. Computing ranges and slices was throwing an exception
This series fixes them both; it also happens to resolve some old TODOs from restriction_test.
Tests: unit (dev, debug)
Closes#7804
* github.com:scylladb/scylla:
cql3: Fix value_for when restriction is impossible
cql3: Fix range computation for p=1 AND p=1
Previously, single_column_restrictions::value_for() assumed that a
column's restriction specifies exactly one value for the column. But
since 37ebe521e3, multiple equalities on the same column are allowed,
so the restriction could be a conjunction of conflicting
equalities (eg, c=1 AND c=0). That violates an assert and crashes
Scylla.
This patch fixes value_for() by gracefully handling the
impossible-restriction case.
Fixes#7772
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Previously compute_bounds was assuming that primary-key columns are
restricted by exactly one equality, resulting in the following error:
query 'select p from t where p=1 and p=1' failed:
std::bad_variant_access (std::get: wrong index for variant)
This patch removes that assumption and deals correctly with the
multiple-equalities case. As a byproduct, it also stops raising
"invalid null value" exceptions for null RHS values.
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
"
This patch series consists of the following patches:
1. The first one turned out to be a massive rewrite of almost
everything in `idl-compiler.py`. It aims to decouple parser
structures from the internal representation which is used
in the code-generation itself.
Prior to the patch everything was working with raw token lists and
the code was extremely fragile and hard to understand and modify.
Moreover, every change in the parser code caused a cascade effect
of breaking things at many different places, since they were relying
on the exact format of output produced by parsing rules.
Now there is a bunch of supplementary AST structures which provide
hierarchical and strongly typed structure as the output of parsing
routine.
It is much easier to verify (by the means of `isinstance`, for example)
and extend since the internal structures used in code-generation are
decoupled from the structure of parsing rules, which are now controlled
by custom parse actions providing high-level abstractions.
It is tested manually by checking that the old code produces exactly
the same autogenerated sources for all Scylla IDLs as the new one.
2 and 3. Cosmetics changes only: fixed a few typos and moved from
old-fashioned `string.Template` to python f-strings.
This improves readability of the idl-compiler code by a lot.
Only one non-functional whitespace change introduced.
4. This patch adds a very basic support for the parser to
understand `const` specifier in case it's used with a template
parameter for a data member in a class, e.g.
struct my_struct {
std::vector<const raft::log_entry> entries;
};
It actually does two things:
* Adjusts `static_asserts` in corresponding serializer methods
to match const-ness of fields.
* Defines a second serializer specialization for const type in
`.dist.hh` right next to non-const one.
This seems to be sufficient for raft-related uses for now.
Please note there is no support for the following cases, though:
const std::vector<raft::log_entry> entries;
const raft::term_t term;
None of the existing IDLs are affected by the change, so that
we can gradually improve on the feature and write the idl
unit-tests to increase test coverage with time.
5. A basic unit-test that writes a test struct with an
`std::vector<S<const T>>` field and reads it back to verify
that serialization works correctly.
6. Basic documentation for AST classes.
TODO: should also update the docs in `docs/IDL.md`. But it is already
quite outdated, and some changes would even be out of scope for this
patch set.
"
* 'idl-compiler-refactor-v5' of https://github.com/ManManson/scylla:
idl: add docstrings for AST classes
idl: add unit-test for `const` specifiers feature
idl: allow to parse `const` specifiers for template arguments
idl: fix a few typos in idl-compiler
idl: switch from `string.Template` to python f-strings and format string in idl-compiler
idl: Decouple idl-compiler data structures from grammar structure
"
The initial intent was to remove call for global storage service from
secondary index manager's create_view_for_index(), but while fixing it
one of intermediate schema table's helper managed to benefit from it
by re-using the database reference flying by.
The cleanup is done by simply pushing the database reference along the
stack from the code that already has it down the create_view_for_index().
tests: unit(dev)
"
* 'br-no-storages-in-index-and-schema' of https://github.com/xemul/scylla:
schema-tables: Use db from make_update_table_mutations in make_update_indices_mutations
schema-tables: Add database argument to make_update_table_mutations
schema-tables: Factor out calls getting database instance
index-manager: Move feature evaluation one level up
The switch to clang disabled the clang-specific -Wunused-value
since it generated some harmless warnings. Unfortunately, that also
prevent [[nodiscard]] violations from warning.
Fix by clearing all instances of the warning (including [[nodiscard]]
violations that crept in while it was disabled) and reinstating the warning.
Closes#7767
* github.com:scylladb/scylla:
build: reinstate -Wunused-value warning for [[nodiscard]]
test: lib: don't ignore future in compare_readers()
test: mutation_test: check both ranges when comparing summaries
serialializer: silence unused value warning in variant deserializer
There are 3 callers of this helper (cdc, migration manager and tests)
and all of them already have the database object at hands.
The argument will be used by next patch to remove call for global
storage proxy instance from make_update_indices_mutations.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The heuristic of STCS reshape is correct, and it built the compaction
descriptor correctly, but forgot to return it to the caller, so no
reshape was ever done on behalf of STCS even when the strategy
needed it.
Fixes#7774.
Signed-off-by: Raphael S. Carvalho <raphaelsc@scylladb.com>
Message-Id: <20201209175044.1609102-1-raphaelsc@scylladb.com>
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.
When built by clang this dev-mode test takes ~30 minutes to
complete. Let's reduce this time by reducing the scale of
the test if DEVEL is set.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
A copy/paste error means we ignore the termination of one of the
ranges. Change the comma expression to a disjunction to avoid
the unused value warning from clang.
The code is not perfect, since if the two ranges are not the same
size we'll invoke undefined behavior, but it is no worse than before
(where we ignored the comparison completely).
"
The storage service is called there to get the cached value
of db::system_keyspace::get_local_host_id(). Keeping the value
on database decouples it from storage service and kills one
more global storage service reference.
tests: unit(dev)
"
* 'br-remove-storage-service-from-counters-2' of https://github.com/xemul/scylla:
counters: Drop call to get_local_storage_service and related
counters: Use local id arg in transform_counter_update_to_shards
database: Have local id arg in transform_counter_updates_to_shards()
storage_service: Keep local host id to database
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.
There are two places that call it -- database code itself and
tests. The former already has the local host id, so just pass
one.
The latter are a bit trickier. Currently they use the value from
storage_service created by storage_service_for_tests, but since
this version of service doesn't pass through prepare_to_join()
the local_host_id value there is default-initialized, so just
default-initialize the needed argument in place.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This abstraction is used to merge the output of multiple readers, each
opened for a single partition query, into a non-decreasing stream
of mutation_fragments.
It is similar to `mutation_reader_merger`,
but an important difference is that the new merger may select new readers
in the middle of a partition after it already returned some fragments
from that partition. It uses the new `position_reader_queue` abstraction
to select new readers. It doesn't support multi-partition (ring range) queries.
The new merger will be later used when reading from sstable sets created
by TimeWindowCompactionStrategy. This strategy creates many sstables
that are mostly disjoint w.r.t the contained clustering keys, so we can
delay opening sstable readers when querying a partition until after we have
processed all mutation fragments with positions before the keys
contained by these sstables.
A microbenchmark was added that compares the existing combining reader
(which uses `mutation_reader_merger` underneath) with a new combining reader
built using the new `clustering_order_reader_merger` and a simple queue of readers
that returns readers from some supplied set. The used set of readers is built from the following
ranges of keys (each range corresponds to a single reader):
`[0, 31]`, `[30, 61]`, `[60, 91]`, `[90, 121]`, `[120, 151]`.
The microbenchmark runs the reader and divides the result by the number of mutation fragments.
The results on my laptop were:
```
$ build/release/test/perf/perf_mutation_readers -t clustering_combined.* -r 10
single run iterations: 0
single run duration: 1.000s
number of runs: 10
test iterations median mad min max
clustering_combined.ranges_generic 2911678 117.598ns 0.685ns 116.175ns 119.482ns
clustering_combined.ranges_specialized 3005618 111.015ns 0.349ns 110.063ns 111.840ns
```
`ranges_generic` denotes the existing combining reader, `ranges_specialized` denotes the new reader.
Split from https://github.com/scylladb/scylla/pull/7437.
Closes#7688
* github.com:scylladb/scylla:
tests: mutation_source_test for clustering_order_reader_merger
perf: microbenchmark for clustering_order_reader_merger
mutation_reader_test: test clustering_order_reader_merger in memory
test: generalize `random_subset` and move to header
mutation_reader: introduce clustering_order_reader_merger
When a row was inserted into a table with no regular columns, and no
such row existed in the first place, postimage would not be produced.
Fix this.
Fixes#7716.
Closes#7723
Previously, statement_restrictions::find_idx() would happily return an
index for a non-EQ restriction (because it checked only the column
name, not the operator). This is incorrect: when the selected index
is for a non-EQ restriction, it is impossible to query that index
table.
Fixes#7659.
Tests: unit (dev)
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Closes#7665
This abstraction is used to merge the output of multiple readers, each
opened for a single partition query, into a non-decreasing stream
of mutation_fragments.
It is similar to `mutation_reader_merger`,
an important difference is that the new merger may select new readers
in the middle of a partition after it already returned some fragments
from that partition. It uses the new `position_reader_queue` abstraction
to select new readers. It doesn't support multi-partition (ring range) queries.
The new merger will be later used when reading from sstable sets created
by TimeWindowCompactionStrategy. This strategy creates many sstables
that are mostly disjoint w.r.t the contained clustering keys, so we can
delay opening sstable readers when querying a partition until after we have
processed all mutation fragments with positions before the keys
contained by these sstables.
Fix#7680 by never using secondary index for multi-column restrictions.
Modify expr::is_supported_by() to handle multi-column correctly.
Tests: unit (dev)
Closes#7699
* github.com:scylladb/scylla:
cql3/expr: Clarify multi-column doesn't use indexing
cql3: Don't use index for multi-column restrictions
test: Add eventually_require_rows
Reject the previously accepted case where the multi-column restriction
applied to just a single column, as it causes a crash downstream. The
user can drop the parentheses to avoid the rejection.
Fixes#7710
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Closes#7712
"
This series adds maybe_yield called from
cleanup_compaction::get_ranges_for_invalidation
to avoid reactor stalls.
To achieve that, we first extract bool_class can_yield
to utils/maybe_yield.hh, and add a convience helper:
utils::maybe_yield(can_yield) that conditionally calls
seastar::thread::maybe_yield if it can (when called in a
seastar thread).
With that, we add a can_yield parameter to dht::to_partition_ranges
and dht::partition_range::deoverlap (defaults to false), and
use it from cleanup_compaction::get_ranges_for_invalidation,
as the latter is always called from `consume_in_thread`.
Fixes#7674
Test: unit(dev)
"
* tag 'unstall-get_ranges_for_invalidation-v2' of github.com:bhalevy/scylla:
compaction: cleanup_compaction: get_ranges_for_invalidation: add yield points
dht/i_partitioner: to_partition_ranges: support yielding
locator: extract can_yield to utils/maybe_yield.hh
The downstream code expects a single-column restriction when using an
index. We could fix it, but we'd still have to filter the rows
fetched from the index table, unlike the code that queries the base
table directly. For instance, WHERE (c1,c2,c3) = (1,2,3) with an
index on c3 can fetch just the right rows from the base table but all
the c3=3 rows from the index table.
Fixes#7680
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
After a node becomes leader it needs to do two things: send an append
message to establish its leadership and commit one entry to make sure
all previous entries with smaller terms are committed as well.
Move the definition of bool_class can_yield to a standalone
header file and define there a maybe_yield(can_yield) helper.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
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
For sstable versions greater or equal than md, the `min_max_column_names`
sstable metadata gives a range of position-in-partitions such that all
clustering rows stored in this sstable have positions in this range.
Partition tombstones in this context are understood as covering the
entire range of clustering keys; thus, if the sstable contains at least
one partition tombstone, the sstable position range is set to be the
range of all clustered rows.
Therefore, by checking that the position range is *not* the range of all
clustered rows we know that the sstable cannot have any partition tombstones.
Closes#7678
Now that CDC is GA, it should be enabled in all the tests by default.
To achieve that the PR adds a special db::config::add_cdc_extension()
helper which is used in cql_test_envm to make sure CDC is usable in
all the tests that use cql_test_env.m As a result, cdc_tests can be
simplified.
Finally, some trailing whitespaces are removed from cdc_tests.
Tests: unit(dev)
Closes#7657
* github.com:scylladb/scylla:
cdc: Remove trailing whitespaces from cdc_tests
cdc: Remove mk_cdc_test_config from tests
config: Add add_cdc_extension function for testing
cdc: Add missing includes to cdc_extension.hh
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.
"
The qctx is global object that references query processor and
database to let the rest of the code query system keyspace.
As the first step of de-globalizing it -- remove the database
reference from it. After the set the qctx remains a simple
wrapper over the query processor (which is already de-globalized)
and the query processor in turn is mostly needed only to parse
the query string into prepared statement only. This, in turn,
makes it possible to remove the qctx later by parsing the
query strings on boot and carrying _them_ around, not the qctx
itself.
tests: unit(dev), dtest(simple_cluster_driver_test:dev), manual start/stop
"
* 'br-remove-database-from-qctx' of https://github.com/xemul/scylla:
query-context: Remove database from qctx
schema-tables: Use query processor referece in save_system(_keyspace)?_schema
system-keyspace: Rewrite force_blocking_flush
system-keyspace: Use cluster_name string in check_health
system-keyspace: Use db::config in setup_version
query-context: Kill global helpers
test: Use cql_test_env::evecute_cql instead of qctx version
code: Use qctx::evecute_cql methods, not global ones
system-keyspace: Do not call minimal_setup for the 2nd time
system-keyspace: Fix indentation after previous patch
system-keyspace: Do not do invoke_on_all by hands
system-keyspace: Remove dead code
Similar to previous patch, but for tests. Since cql_test_env
does't have qctx on board, the patch makes one step forward
and calls what is called by qctx::execute_cql.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Now that CDC is GA and enabled by default, there's no longer a need
for a specific config in CDC tests.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
"
We've recently seen failures in this unit test as follows:
```
test/boost/network_topology_strategy_test.cc(0): Entering test case "testCalculateEndpoints"
unknown location(0): fatal error: in "testCalculateEndpoints": std::out_of_range: _Map_base::at
./seastar/src/testing/seastar_test.cc(43): last checkpoint
test/boost/network_topology_strategy_test.cc(0): Leaving test case "testCalculateEndpoints"; testing time: 15192us
test/boost/network_topology_strategy_test.cc(0): Entering test case "test_invalid_dcs"
network_topology_strategy_test: ./seastar/include/seastar/core/future.hh:634: void seastar::future_state<seastar::internal::monostate>::set(A &&...) [T = seastar::internal::monostate, A = <>]: Assertion `_u.st == state::future' failed.
Aborting on shard 0.
```
This series fixes 2 issues in this test:
1. The core issue where std::out_of_range exception
is not handled in calculate_natural_endpoints().
2. A secondary issue where the static `snitch_inst` isn't
stopped when the first exception is hit, failing
the next time the snitch is started, as it wasn't
stopped properly.
Test: network_topology_strategy_test(release)
"
* tag 'nts_test-harden-calculate_natural_endpoints-v1' of github.com:bhalevy/scylla:
test: network_topology_strategy_test: has_sufficient_replicas: handle empty dc endpoints case
test: network_topology_strategy_test: fixup indentation
test: network_topology_strategy_test: always stop_snitch after create_snitch
We saw this intermittent failure in testCalculateEndpoints:
```
unknown location(0): fatal error: in "testCalculateEndpoints": std::out_of_range: _Map_base::at
```
It turns out that there are no endpoints associated with the dc passed
to has_sufficient_replicas in the `all_endpoints` map.
Handle this case by returning true.
The dc is still required to appear in `dc_replicas`,
so if it's not found there, fail the test gracefully.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently stop_snitch is not called if the test fails on exception.
This causes a failure in create_snitch where snitch_inst fails to start
since it wasn't stopped earlier.
For example:
```
test/boost/network_topology_strategy_test.cc(0): Entering test case "testCalculateEndpoints"
unknown location(0): fatal error: in "testCalculateEndpoints": std::out_of_range: _Map_base::at
./seastar/src/testing/seastar_test.cc(43): last checkpoint
test/boost/network_topology_strategy_test.cc(0): Leaving test case "testCalculateEndpoints"; testing time: 15192us
test/boost/network_topology_strategy_test.cc(0): Entering test case "test_invalid_dcs"
network_topology_strategy_test: ./seastar/include/seastar/core/future.hh:634: void seastar::future_state<seastar::internal::monostate>::set(A &&...) [T = seastar::internal::monostate, A = <>]: Assertion `_u.st == state::future' failed.
Aborting on shard 0.
Backtrace:
0x0000000002825e94
0x000000000282ffa9
0x00007fd065f971df
/lib64/libc.so.6+0x000000000003dbc4
/lib64/libc.so.6+0x00000000000268a3
/lib64/libc.so.6+0x0000000000026788
/lib64/libc.so.6+0x0000000000035fc5
0x0000000000b484cf
0x0000000002a7c69f
0x0000000002a7c62f
0x0000000000b47b9e
0x0000000002595da2
0x0000000002595913
0x0000000002a83a31
```
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
scoped_critical_alloc_section was recently introduced to replace
disable_failure_guard and made the old class deprecated.
This patch replaces all occurences of disable_failure_guard with
scoped_critical_alloc_section.
Without this patch the build prints many warnings like:
warning: 'disable_failure_guard' is deprecated: Use scoped_critical_section instead [-Wdeprecated-declarations]
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <ca2a91aaf48b0f6ed762a6aa687e6ac5e936355d.1605621284.git.piotr@scylladb.com>
As requested in #7057, allow certain alterations of system_auth tables. Potentially destructive alterations are still rejected.
Tests: unit (dev)
Closes#7606
* github.com:scylladb/scylla:
auth: Permit ALTER options on system_auth tables
auth: Add command_desc
auth: Add tests for resource protections
These alterations cannot break the database irreparably, so allow
them.
Expand command_desc as required.
Add a type (rather than command_desc) parameter to
has_column_family_access() to minimize code changes.
Fixes#7057
Signed-off-by: Dejan Mircevski <dejan@scylladb.com>
Add new alternator-streams experimental flag for
alternator streams control.
CDC becomes GA and won't be guarded by an experimental flag any more.
Alternator Streams stay experimental so now they need to be controlled
by their own experimental flag.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
"
This series is a rebased version of 3 patchsets that were sent
separately before:
1. [PATCH v4 00/17] Cleanup storage_service::update_pending_ranges et al.
This patchset cleansup service/storage_service use of
update_pending_ranges and replicate_to_all_cores.
It also moves some functionality from gossiping_property_file_snitch::reload_configuration
into a new method - storage_service::update_topology.
This prepares storage_service for using a shared ptr to token_metadata,
updating a copy out of line under a semaphore that serializes writers,
and eventually replicating to updated copy to all shards and releasing
the lock. This is a follow up to #7044.
2. [PATCH v8 00/20] token_metadata versioned shared ptr
Rather than keeping references on token_metadata use a shared_token_metadata
containing a lw_shared_ptr<token_metadata> (a.k.a token_metadata_ptr)
to keep track of the token_metadata.
Get token_metadata_ptr for a read-only snapshot of the token_metadata
or clone one for a mutable snapshot that is later used to safely update
the base versioned_shared_object.
token_metadata_ptr is used to modify token_metadata out of line, possibly with
multiple calls, that could be preeempted in-between so that readers can keep a consistent
snapshot of it while writers prepare an updated version.
Introduce a token_metadata_lock used to serialize mutators of token_metadata_ptr.
It's taken by the storage_service before cloning token_metadata_ptr and held
until the updated copy is replicated on all shards.
In addition, this series introduces token_metadata::clone_async() method
to copy the tokne_metadata class using a asynchronous function with
continuations to avoid reactor stalls as seen in #7220.
Fixes#7044
3. [PATCH v3 00/17] Avoid stalls in token_metadata and replication strategy
This series uses the shared_token_metadata infrastructure.
First patches in the series deal wth cloning token_metadata
using continuations to allow preemption while cloning (See #7220).
Then, the rest of the series makes sure to always run
`update_pending_ranges` and `calculate_pending_ranges_for_*` in a thread,
it then adds a `can_yield` parameter to the token_metadata and abstract_replication_strategy
`get_pending_ranges` and friends, and finally it adds `maybe_yield` calls
in potentially long loops.
Fixes#7313Fixes#7220
Test: unit (dev)
Dtest: gating(dev)
"
* tag 'replication_strategy_can_yield-v4' of github.com:bhalevy/scylla: (54 commits)
token_metadata_impl: set_pending_ranges: add can_yield_param
abstract_replication_strategy: get rid of get_ranges_in_thread
repair: call get_ranges_in_thread where possible
abstract_replication_strategy: add can_yield param to get_pending_ranges and friends
abstract_replication_strategy: define can_yield bool_class
token_metadata_impl: calculate_pending_ranges_for_* reindent
token_metadata_impl: calculate_pending_ranges_for_* pass new_pending_ranges by ref
token_metadata_impl: calculate_pending_ranges_for_* call in thread
token_metadata: update_pending_ranges: create seastar thread
abstract_replication_strategy: add get_address_ranges method for specific endpoint
token_metadata_impl: clone_after_all_left: sort tokens only once
token_metadata: futurize clone_after_all_left
token_metadata: futurize clone_only_token_map
token_metadata: use mutable_token_metadata_ptr in calculate_pending_ranges_for_*
repair: replace_with_repair: use token_metadata::clone_async
storage_service: reindent token_metadata blocks
token_metadata: add clone_async
abstract_replication_strategy: accept a token_metadata_ptr in get_pending_address_ranges methods
abstract_replication_strategy: accept a token_metadata_ptr in get_ranges methods
boot_strapper: get_*_tokens: use token_metadata_ptr
...
