Commit Graph

1297 Commits

Author SHA1 Message Date
Rafael Ávila de Espíndola
336d541f58 database: Use a flat_hash_map for _ks_cf_to_uuid
Given that the key is a std::pair, we have to explicitly mark the hash
and eq types as transparent for heterogeneous lookup to work.

With that, pass std::string_view to a few functions that just check if
a value is in the map.

This increases the .text section by 11 KiB (0.03%).

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
2020-06-14 08:18:39 -07:00
Rafael Ávila de Espíndola
6da9eef25f database: Use flat_hash_map for _keyspaces
This changes the hash map used for _keyspaces. Using a flat_hash_map
allows using std::string_view in has_keyspace thanks to the
heterogeneous lookup support.

This add 200 KiB to .text, since this is the first use of absl and
brings in files from the .a.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
2020-06-14 08:18:39 -07:00
Juliusz Stasiewicz
e04fd9f774 counters: Read the state under timeout
Counter update is a RMW operation. Until now the "Read" part was
not guarded by a timeout, which is changed in this patch.

Fixes #5069
2020-06-02 15:10:43 +03:00
Pavel Emelyanov
67d5fad65f storage_service: Remove some inclusions of its header
GC pass over .cc files. Some really do not need it, some need for features/gossiper

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-06-01 09:08:40 +03:00
Botond Dénes
e678f06a5e querier_cache: get semaphore from querier
Currently the `querier_cache` is passed a semaphore during its
construction and it uses this semaphore to do all the inactive reader
registering/unregistering. This is inaccurate as in theory cached reads
could belong to different semaphores (although currently this is not yet
the case). As all queriers store a valid permit now, use this
permit to obtain the semaphore the querier is associated with, and
register the inactive read with this semaphore.
2020-05-28 11:34:35 +03:00
Botond Dénes
0f55e8e30f database: make_multishard_streaming_reader: pass valid permit to multi range reader
The permit is not used by the mutation source passed to it, but empty
permits will soon be forbidden, so we have to pass a valid one.
2020-05-28 11:34:35 +03:00
Botond Dénes
734e995639 database: add compaction read concurrency semaphore
All reads will soon require a valid permit, including those done during
compaction. To allow creating valid permits for these reads create a
compaction specific semaphore. This semaphore is unlimited as compaction
concurrency is managed by higher level layer, we use just for resource
usage accounting.
2020-05-28 11:34:35 +03:00
Botond Dénes
992e697dd5 view: use valid permits for reads from the base table
View update generation involves reading existing values from the base
table, which will soon require a valid permit to be passed to it, so
make sure we create and pass a valid permit to these reads.
We use `database::make_query_class_config()` to obtain the semaphore for
the read which selects the appropriate user/system semaphore based on
the scheduling group the base table write is running in.
2020-05-28 11:34:35 +03:00
Botond Dénes
639bbefcd3 database: use valid permit for counter read-before-write
Counter writes involve a read-before-write, which will soon require a
valid permit to be passed to it, so make sure we create and pass a valid
permit to this read. We use `database::make_query_class_config()` to
obtain the semaphore for the read which selects the appropriate
user/system semaphore based on the scheduling group the counter write is
running in.
2020-05-28 11:34:35 +03:00
Botond Dénes
e4c591aa67 database: introduce make_query_class_config()
And use it to obtain any query-class specific configuration that was
obtained from `table::config` before, such as the read concurrency
semaphore and the max memory limit for unlimited queries. As all users
of these items get these from the query class config now, we can remove
them from `table::config`.
2020-05-28 11:34:35 +03:00
Botond Dénes
14743c4412 data_query, mutation_query: use query_class_config
We want to move away from the current practice of selecting the relevant
read concurrency semaphore inside `table` and instead want to pass it
down from `database` so that we can pass down a semaphore that is
appropriate for the class of the query. Use the recently created
`query_class_config` struct for this. This is added as a parameter to
`data_query`, `mutation_query` and propagated down to the point where we
create the `querier` to execute the read. We are already propagating
down a parameter down the same route -- max_memory_reverse_query --
which also happens to be part of `query_class_config`, so simply replace
this parameter with a `query_class_config` one. As the lower layers are
not prepared for a semaphore passed from above, make sure this semaphore
is the same that is selected inside `table`. After the lower layers are
prepared for a semaphore arriving from above, we will switch it to be
the appropriate one for the class of the query.
2020-05-28 11:34:35 +03:00
Botond Dénes
0b4ec62332 flat_mutation_reader: flat_multi_range_reader: add reader_permit parameter
Mutation sources will soon require a valid permit so make sure we have
one and pass it to the mutation sources when creating the underlying
readers.
For now, pass no_reader_permit() on call sites, deferring the obtaining
of a valid permit to later patches.
2020-05-28 11:34:35 +03:00
Botond Dénes
e0b98ba921 database: give system reads a concurrency boost during startup
In the next patches we will match reads to the appropriate reader
concurrency semaphore based on the scheduling group they run in. This
will result in a lot of system reads that are executed during startup
and that were up to now (incorrectly) using the user read semaphore to
switch to the system read semaphore. This latter has a much more
constrained concurrency, which was observed to cause system reads to
saturate and block on the semaphore, slowing down startup.
To solve this, boost the concurrency of the system read semaphore during
startup to match that of the user semaphore. This is ok, as during
startup there are no user reads to compete with. After startup, before
we start serving user reads the concurrency is reverted back to the
normal value.
2020-05-28 10:40:08 +03:00
Tomasz Grabiec
1424543e11 Merge "Move sstables_format on sstable_manager" from Pavel Emelyanov
The format is currently sitting in storage_service, but the
previous set patched all the users not to call it, instead
they use sstables_manager to get the highest supported format.
So this set finalizes this effort and places the format on
sstables_manager(s).

The set introduces the db::sstables_format_selector, that

 - starts with the lowest format (ka)
 - reads one on start from system tables
 - subscribes on sstables-related features and bumps
   up the selection if the respective feature is enabled

During its lifetime the selector holds a reference to the
sharded<database> and updates the format on it, the database,
in turn, propagates it further to sstables_managers. The
managers start with the highest known format (mc) which is
done for tests.

* https://github.com/xemul/scylla br-move-sstables-format-4:
  storage_service: Get rid of one-line helpers
  system_keyspace: Cleanup setup() from storage_service
  format_selector: Log which format is being selected
  sstables_manager: Keep format on
  format_selector: Make it standalone
  format_selector: Move the code into db/
  format_selector: Select format locally
  storage_service: Introduce format_selector
  storage_service: Split feature_enabled_listener::on_enabled
  storage_service: Tossing bits around
  features: Introduce and use masked features
  features: Get rid of per-features booleans
2020-05-27 08:40:05 +03:00
Pavel Emelyanov
89a1b09214 sstables_manager: Keep format on
Make the database be the format_selector target, so
when the format is selected its set on database which
in turn just forwards the selection into sstables
managers. All users of the format are already patched
to read it from those managers.

The initial value for the format is the highest, which
is needed by tests. When scylla starts the format is
updated by format_selector, first after reading from
system tables, then by selectiing it from features.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-05-25 14:17:28 +03:00
Piotr Sarna
92aadb94e5 treewide: propagate trace state to write path
In order to add tracing to places where it can be useful,
e.g. materialized view updates and hinted handoff, tracing state
is propagated to all applicable call sites.
2020-05-18 16:05:23 +02:00
Avi Kivity
beaeda5234 database: remove variadic future from query() and query_mutations()
Variadic futures are deprecated; replace with future<std::tuple<...>>.

Tests: unit (dev)
2020-05-17 18:45:38 +02:00
Glauber Costa
7423ccc318 compaction_manager: allow early aborts through abort sources.
The shutdown process of compaction manager starts with an explicit call
from the database object. However that can only happen everything is
already initialized. This works well today, but I am soon to change
the resharding process to operate before the node is fully ready.

One can still stop the database in this case, but reshardings will
have to finish before the abort signal is processed.

This patch passes the existing abort source to the construction of the
compaction_manager and subscribes to it. If the abort source is
triggered, the compaction manager will react to it firing and all
compactions it manages will be stopped.

We still want the database object to be able to wait for the compaction
manager, since the database is the object that owns the lifetime of
the compaction manager. To make that possible we'll use a future
that is return from stop(): no matter what triggered the abort, either
an early abort during initial resharding or a database-level event like
drain, everything will shut down in the right order.

The abort source is passed to the database, who is responsible from
constructing the compaction manager.

Signed-off-by: Glauber Costa <glauber@scylladb.com>
2020-05-13 16:51:25 -04:00
Glauber Costa
e29701ca1c compaction_manager: expand state to be able to differentiate between enabled and stopped
We are having many issues with the stop code in the compaction_manager.
Part of the reason is that the "stopped" state has its meaning overloaded
to indicate both "compaction manager is not accepting compactions" and
"compaction manager is not ready or destructed".

In a later step we could default to enabled-at-start, but right now we
maintain current behavior to minimize noise.

It is only possible to stop the compaction manager once.
It is possible to enable / disable the compaction manager many times.

Signed-off-by: Glauber Costa <glauber@scylladb.com>
2020-05-13 16:51:25 -04:00
Avi Kivity
5b971397aa Revert "compaction_manager: allow early aborts through abort sources."
This reverts commit e8213fb5c3. It results
in an assertion failure in remove_index_file_test.

Fixes #6413.
2020-05-10 12:32:18 +03:00
Glauber Costa
e8213fb5c3 compaction_manager: allow early aborts through abort sources.
The shutdown process of compaction manager starts with an explicit call
from the database object. However that can only happen everything is
already initialized. This works well today, but I am soon to change
the resharding process to operate before the node is fully ready.

One can still stop the database in this case, but reshardings will
have to finish before the abort signal is processed.

This patch passes the existing abort source to the construction of the
compaction_manager and subscribes to it. If the abort source is
triggered, the compaction manager will react to it firing and all
compactions it manages will be stopped.

We still want the database object to be able to wait for the compaction
manager, since the database is the object that owns the lifetime of
the compaction manager. To make that possible we'll use a future
that is return from stop(): no matter what triggered the abort, either
an early abort during initial resharding or a database-level event like
drain, everything will shut down in the right order.

The abort source is passed to the database, who is responsible from
constructing the compaction manager.

Tests: unit (dev), manual start+stop, manual drain + stop

Signed-off-by: Glauber Costa <glauber@scylladb.com>
Message-Id: <20200506184749.98288-1-glauber@scylladb.com>
2020-05-07 13:24:47 +03:00
Avi Kivity
88ade3110f treewide: replace calls to engine().some_api() with some_api()
This removes the need to include reactor.hh, a source of compile
time bloat.

In some places, the call is qualified with seastar:: in order
to resolve ambiguities with a local name.

Includes are adjusted to make everything compile. We end up
having 14 translation units including reactor.hh, primarily for
deprecated things like reactor::at_exit().

Ref #1
2020-04-05 12:46:04 +03:00
Botond Dénes
240b5e0594 frozen_schema: key() remove unused schema parameter
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200402092249.680210-1-bdenes@scylladb.com>
2020-04-02 14:43:35 +02:00
Botond Dénes
0d224210bb database: apply_in_memory(): don't look-up the column-family twice
The column-family is already looked up as the first line in the method.
No need to repeat that lookup in the lambda passed to
`run_when_memory_available()`, we can just capture the reference to the
already obtained column-family object. These objects are safe to
reference, they don't just disappear in the middle of an operation.

Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20200327140827.128647-1-bdenes@scylladb.com>
2020-03-27 15:19:32 +01:00
Rafael Ávila de Espíndola
c5795e8199 everywhere: Replace engine().cpu_id() with this_shard_id()
This is a bit simpler and might allow removing a few includes of
reactor.hh.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20200326194656.74041-1-espindola@scylladb.com>
2020-03-27 11:40:03 +03:00
Rafael Ávila de Espíndola
eca0ac5772 everywhere: Update for deprecated apply functions
Now apply is only for tuples, for varargs use invoke.

This depends on the seastar changes adding invoke.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20200324163809.93648-1-espindola@scylladb.com>
2020-03-25 08:49:53 +02:00
Piotr Jastrzebski
924ed7bb1c make_multishard_combining_reader: stop taking partitioner
The function already takes schema so there's no need
for it to take partitioner. It can be obtained using
schema::get_partitioner

Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
2020-03-15 10:25:20 +01:00
Avi Kivity
6b747f4673 database: avoid creating thread in make_directory_for_column_family()
make_directory_for_column_family() is used in a parallel_for_each() in
parse_system_tables(). Because parallel_for_each does not preempt
in the initial execution of its input function, and because each thread
allocates 128k for the stack, we end up allocating many hundreds of
megabytes if there are many tables.

This happens early during boot and will only cause problems if
there are 5,000 tables per gigabyte of shard memory, and unlikely
combination that will probably fail later, but still it is better to
avoid unnecessary large allocations.

This was developed in order to fix #6003, until it was discovered that
c020b4e5e2 ("logalloc: increase capacity of _regions vector
outside reclaim lock") is the real fix.

Message-Id: <20200313093603.1366502-1-avi@scylladb.com>
2020-03-13 13:46:45 +02:00
Piotr Jastrzebski
54d24553bb schema: get_partitioner return const&
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
2020-03-06 13:33:53 +01:00
Avi Kivity
906784639d Merge "Clean sstables from using global objects" from Pavel E
"
This set cleans sstable_writer_config and surrounding sstables
code from using global storage_ and feature_ service-s and database
by moving the configuration logic onto sstables_manager (that
was supposed to do it since eebc3701a5).

Most of the complexity is hidden around sstable_writer_config
creation, this set makes the sstables_manager create this object
with an explicit call. All the rest are consequences of this change.

Tests: unit(debug), manual start-stop
"

* 'br-clean-sstables-manager-2' of https://github.com/xemul/scylla:
  sstables: Move get_highest_supported_format
  sstables: Remove global get_config() helper
  sstables: Use manager's config() in .new_sstable_component_file()
  sstable_writer_config: Extend with more db::config stuff
  sstables_manager: Don't use global helper to generate writer config
  sstable_writer_config: Sanitize out some features fields initialization
  sstable_writer_config: Factor out some field initialization
  sstables: Generate writer config via manager only
  sstables: Keep reference on manager
  test: Re-use existing global sstables_manager
  table: Pass sstable_writer_config into write_memtable_to_sstable
2020-03-03 18:33:01 +02:00
Avi Kivity
157fe4bd19 Merge "Remove default timeouts" from Botond
"
Timeouts defaulted to `db::no_timeout` are dangerous. They allow any
modifications to the code to drop timeouts and introduce a source of
unbounded request queue to the system.

This series removes the last such default timeouts from the code. No
problems were found, only test code had to be updated.

tests: unit(dev)
"

* 'no-default-timeouts/v1' of https://github.com/denesb/scylla:
  database: database::query*(), database::apply*(): remove default timeouts
  database: table::query(): remove default timeout
  mutation_query: data_query(): remove default timeout
  mutation_query: mutation_query(): remove default timeout
  multishard_mutation_query: query_mutations_on_all_shards(): remove default timeout
  reader_concurrency_semaphore: wait_admission(): remove default timeout
  utils/logallog: run_when_memory_available(): remove default timeout
2020-03-01 17:29:17 +02:00
Rafael Ávila de Espíndola
ba453d832b Pass string_view to keyspace_metadata::new_keyspace
This avoids a few sstring copies.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
2020-02-28 17:04:12 -08:00
Rafael Ávila de Espíndola
94d07fba07 Pass string_view to the keyspace_metadata constructor
This avoids a few sstring copies when constructing keyspace_metadata.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
2020-02-28 17:04:12 -08:00
Rafael Ávila de Espíndola
2b96abcece Pass string_view to no_such_column_family's constructor
With this we don't have to construct a sstring to construct a
no_such_column_family.

Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
2020-02-28 08:36:27 -08:00
Botond Dénes
fdb45d16de mutation_query: mutation_query(): remove default timeout 2020-02-27 18:56:30 +02:00
Botond Dénes
93039a085d utils/logallog: run_when_memory_available(): remove default timeout 2020-02-27 18:36:32 +02:00
Botond Dénes
7bdeec4b00 flat_mutation_reader: make_reversing_reader(): add memory limit
If the reversing requires more memory than the limit, the read is
aborted. All users are updated to get a meaningful limit, from the
respective table object, with the exception of tests of course.
2020-02-27 18:11:54 +02:00
Botond Dénes
75efa707ce db/config: add config memory limit of otherwise unlimited queries
We have a few kind of queries whose memory consumption is not limited at
all. One of these is reverse queries, which reads entire partitions into
memory, before reversing them. These partitions can be larger than
memory and thus such a query can single-handedly cause OOM.
This patch introduces a configuration for a memory limit for such
queries. This will serve as a hard limit and queries which attempt to
use more memory than this, will be aborted.
The limit is propagated to table objects, with the intention of keeping
system tables unlimited. These tables are usually small and initiators
of system queries are not prepared for failures.
2020-02-27 18:11:54 +02:00
Pavel Emelyanov
7363d56946 sstables: Move get_highest_supported_format
The global get_highest_supported_format helper and its declaration
are scattered all over the code, so clean this up and prepare the
ground for moving _sstables_format from the storage_service onto
the sstables_manager (not this set).

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-02-25 14:31:45 +03:00
Pavel Emelyanov
85d9326d70 sstables_manager: Don't use global helper to generate writer config
The main goal of this patch is to stop using get_config() glbal
when creating the sstable_writer_config instance.

Other than being global the existing get_config() is also confusing
as it effectively generates 3 (three) sorts of configs -- one for
scylla, when db config and features are ready, the other one for
tests, when no storage service is at hands, and the third one for
tests as well, when the storage service is created by test env
(likely intentionally, but maybe by coincidence the resulting config
is the same as for no-storage-service case).

With this patch it's now 100% clear which one is used when. Also
this makes half the work of removing get_config() helper.

The db::config and feature_service used to initialize the managers
are referenced by database that creates and keeps managers on,
so the references are safe.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-02-25 14:31:04 +03:00
Piotr Sarna
5e07c00eeb Merge 'Delete table snapshot' from Amnon
This series adds an option to the API that supports deleting
a specific table from a snapshot.
The implementation works in a similar way to the option
to specify specific keyspaces when deleting a snapshot.
The motivation is to allow reducing disk-space when using
the snapshot for backup. A dtest PR is sent to the dtest
repository.

Fixes #5658

Original PR #5805

Tests: (database_test) (dtest snapshot_test.py:TestSnapshot.test_cleaning_snapshot_by_cf)

* amnonh/delete_table_snapshot:
  test/boost/database_test: adopt new clear_snapshot signature
  api/storage_service: Support specifying a table when deleting a snapshot
  storage_service: Add optional table name to clear snapshot

* amnonh/delete_table_snapshot:
  test/boost/database_test: adopt new clear_snapshot signature
  api/storage_service: Support specifying a table when deleting a snapshot
  storage_service: Add optional table name to clear snapshot
2020-02-24 09:38:57 +01:00
Pavel Emelyanov
8435e93549 db: Move unbounded_range_tombstones listening from storage_service
Now the database keeps reference on feature service, so we
can listen on the feature in it directly.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-02-19 14:08:24 +03:00
Amnon Heiman
c3260bad25 storage_service: Add optional table name to clear snapshot
There are cases when it is useful to delete specific table from a
snapshot.

An example is when a snapshot is used for backup. Backup can take a long
period of time, during that time, each of the tables can be deleted once
it was backup without waiting for the entire backup process to
completed.

This patch adds such an option to the database and to the storage_service
wrapping method that calls it.

If a table is specified a filter function is created that filter only
the column family with that given name.

This is similar to the filtering at the keyspace level.

Signed-off-by: Amnon Heiman <amnon@scylladb.com>
2020-02-18 16:34:10 +02:00
Avi Kivity
6c7aa18238 Merge "Introduce schema::get_partitioner" from Piotr
"
Introduce schema::get_partitioner and use it instead of dht::global_partitioner.

Fixes #5493

Tests: unit(dev, release, debug)
"

* 'per_table_partitioner_prep' of https://github.com/haaawk/scylla: (35 commits)
  cdc: stop using partitioners
  partitioner_test: stop calling set_global_partitioner
  storage_service: stop calling global_partitioner()
  mutation_writer_test: stop calling global_partitioner()
  schema: reduce number of global_partitioner() calls
  test_services: stop calling global_partitioner()
  sstable_utils: stop calling global_partitioner()
  sstable_resharding_test: stop depending on global partitioner
  sstable_mutation_test: stop calling global_partitioner()
  sstable_data_file_test: stop calling global_partitioner()
  random_schema: stop taking partitioner in constructor
  mutation_reader_test: stop calling global_partitioner()
  multishard_mutation_query_test: stop calling global_partitioner()
  row_level repair: stop calling global_partitioner()
  distribute_reader_and_consume_on_shards: don't take partitioner
  thrift: reduce global_partitioner() calls
  binary_search: stop calling global_partitioner()
  index_entry: stop calling global_partitioner()
  mc writer: stop calling global_partitioner()
  sstable: stop calling global_partitioner()
  ...
2020-02-17 18:12:53 +02:00
Piotr Dulikowski
01084a79b8 hh: send orphaned hints on HINT_MUTATION verb
When replaying a hint with a destination node that is no longer in the
cluster, it will be sent with cl=ALL to all its new replicas. Before
this patch, the MUTATION verb was used, which causes such hints to be
handled on the same connection and with the same priority as regular
writes. This can cause problems when a large number of hints is
orphaned and they are scheduled to be sent at once. Such situation
may happen when replacing a dead node - all nodes that accumulated hints
for the dead node will now send them with cl=ALL to their new replicas.

This patch changes the verb used to send such hints to HINT_MUTATION.
This verb is handled on a separate connection and with streaming
scheduling group, which gives them similar priority to non-orphaned
hints.

Refs: #4712

Tests: unit(dev)
2020-02-17 14:45:22 +01:00
Piotr Jastrzebski
2d7532f87f dht: add dht::get_token
and replace all calls to dht::global_partitioner().get_token

dht::get_token is better because it takes schema and uses it
to obtain partitioner instead of using a global partitioner.

Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
2020-02-17 10:59:15 +01:00
Piotr Jastrzebski
abd76e566f dht::shard_of: stop calling global_partitioner()
Take const schema& as a parameter of shard_of and
use it to obtain partitioner instead of calling
global_partitioner().

Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
2020-02-17 10:23:16 +01:00
Pavel Emelyanov
1a3f78a57d database: Use own token_metadata
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-02-10 20:54:32 +03:00
Pavel Emelyanov
de1dc59548 migration_manager: Refactor validation of new/updating ksm
The goal is to have token_metadata reference intide the
keyspace_metadata.validate method. This can be acheived
by doing the validation through the database reference
which is "at hands" in migration_manager.

While at it, merge the validation with exists/not-exists
checks done in the same places.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2020-02-10 18:10:38 +03:00
Avi Kivity
bed61b96a2 Merge "Move features from storage- into feature-service" from Pavel
"
There's a lot of code around that needs storage service purely to
get the specific feature value (cluster_supports_<something> calls).
This creates several circular dependencies, e.g. storage_service <->
migration_manager one and database <-> storage_servuce. Also features
sit on storage_service, but register themselfs on the feature_service
and the former subscribes on them back which also looks strange.

I propose to keep all the features on feature_service, this keeps the
latter intependent from other components, makes it possible to break
one of the mentioned circle dependencyand heavily relax the other.

Also the set helps us fighting the globals and, after it, the
feature_service can be safely stopped at the very last moment.

Tests: unit(dev), manual debug build start-stop
"

* 'br-features-to-service-5' of https://github.com/xemul/scylla:
  gossiper: Avoid string merge-split for nothing
  features: Stop on shutdown
  storage_service: Remove helpers
  storage_service: Prepare to switch from on-board feature helpers
  cql3: Check feature in .validate
  database: Use feature service
  storage_proxy: Use feature service
  migration_manager: Use feature service
  start: Pass needed feature as argument into migrate_truncation_records
  features: Unfriend storage_service
  features: Simplify feature registration
  features: Introduce known_feature_set
  features: Move disabled features set from storage_service
  features: Move schema_features helper
  features: Move all features from storage_service to feature_service
  storage_service: Use feature_config from _feature_service
  features: Add feature_config
  storage_service: Kill set_disabled_features
  gms: Move features stuff into own .cc file
  migration_manager: Move some fns into class
2020-02-09 19:22:07 +02:00