The code that creates system keyspace open code a lot of things from
database::create_keyspace(). The patch makes create_keyspace() suitable
for both system and non system keyspaces and uses it to create system
keyspaces as well.
Message-Id: <20210209160506.1711177-1-gleb@scylladb.com>
Refs #6148
Commitlog disk limit was previously a "soft" limit, in that we allowed allocating new segments, even if we were over
disk usage max. This would also cause us sometimes to create new segments and delete old ones, if badly timed in
needing and releasing segments, in turn causing useless disk IO for pre-allocation/zeroing.
This patch set does:
* Make limit a hard limit. If we have disk usage > max, we wait for delete or recycle.
* Make flush threshold configurable. Default is ask for flush when over 50% usage. (We do not wait for results)
* Make flush "partial". We flush X% of the used space (used - thres/2), and make the rp limit accordingly. This means we will try to clear the N oldest segments, not all. I.e. "lighter" flush. Of course, if the CL is wholly dominated by a single CF, this will not really help much. But when > 1 cf is used, it means we can skip those not having unflushed data < req rp.
* Force more eager flush/recycle if we're out of segments
Note: flush threshold is not exposed in scylla config (yet). Because I am unsure of wording, and even if it should.
Note: testing is sparse, esp. in regard to latency/timeouts added in high usage scenarios. While I can fairly easily provoke "stalls" (i.e. forced waiting for segments to free up) with simple C-S, it is hard to say exactly where in a more sane config (I set my limits looow) latencies will start accumulating.
Closes#7879
* github.com:scylladb/scylla:
commitlog: Force earlier cycle/flush iff segment reserve is empty
commitlog: Make segment allocation wait iff disk usage > max
commitlog: Do partial (memtable) flushing based on threshold
commitlog: Make flush threshold configurable
table: Add a flush RP mark to table, and shortcut if not above
The db::update_keyspace() needs sharded<storage_proxy>
reference, but the only caller of it already has it and
can pass one as argument.
tests: unit(dev)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210205175611.13464-3-xemul@scylladb.com>
"
Currently inactive readers are stored in two different places:
* reader concurrency semaphore
* querier cache
With the latter registering its inactive readers with the former. This
is an unnecessarily complex (and possibly surprising) setup that we want
to move away from. This series solves this by moving the responsibility
if storing of inactive reads solely to the reader concurrency semaphore,
including all supported eviction policies. The querier cache is now only
responsible for indexing queriers and maintaining relevant stats.
This makes the ownership of the inactive readers much more clear,
hopefully making Benny's work on introducing close() and abort() a
little bit easier.
Tests: unit(release, debug:v1)
"
* 'unify-inactive-readers/v2' of https://github.com/denesb/scylla:
reader_concurrency_semaphore: store inactive readers directly
querier_cache: store readers in the reader concurrency semaphore directly
querier_cache: retire memory based cache eviction
querier_cache: delegate expiry to the reader_concurrency_semaphore
reader_concurrency_semaphore: introduce ttl for inactive reads
querier_cache: use new eviction notify mechanism to maintain stats
reader_concurrency_semaphore: add eviction notification facility
reader_concurrency_semaphore: extract evict code into method evict()
Adds a second RP to table, marking where we flushed last.
If a new flush request comes in that is below this mark, we
can skip a second flush.
This is to (in future) support incremental CL flush.
Fixes#7732
When truncating with auto_snapshot on, we try to verify the low rp mark
from the CF against the sstables discarded by the truncation timestamp.
However, in a scenario like:
Fill memtables
Flush
Truncate with snapshot A
Fill memtables some more
Truncate
Move snapshot A to upload + refresh (load old tables)
Truncate
The last op will assert, because while we have sstables loaded, which
will be discarded now, we did not in fact generate any _new_ ones
(since memtables are empty), and the RP we get back from discard is
one from an earlier generation set.
(Any permutation of events that create the situation "empty memtable" +
"non-empty sstables with only old tables" will generate the same error).
Added a check that before flushing checks if we actually have any
data, and if not, does not uphold the RP relation assert.
Closes#7799
We already wait for pending reads and writes, so for completeness
we should also wait for all pending stream operations to finish
before dropping the table to avoid inconsistencies.
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>
The method is called after query_processor::execute_internal
to flush the cf. Encapsulating this flush inside database and
getting the database from query_processor lets removing
database reference from global qctx object.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
available_memory is used to seed many caches and controllers. Usually
it's detected from the environment, but unit tests configure it
on their own with fake values. If they forget, then the undefined
behavior sanitizer will kick in in random places (see 8aa842614a
("test: gossip_test: configure database memory allocation correctly")
for an example.
Prevent this early by asserting that available_memory is nonzero.
Closes#7612
Commit e5be3352cf ("database, streaming, messaging: drop
streaming memtables") removed streaming memtables; this removes
the mechanisms to synchronize them: _streaming_flush_gate and
_streaming_flush_phaser. The memory manager for streaming is removed,
and its 10% reserve is evenly distributed between memtables and
general use (e.g. cache).
Note that _streaming_flush_phaser and _streaming_flush_date are
no longer used to syncrhonize anything - the gate is only used
to protect the phaser, and the phaser isn't used for anything.
Closes#7454
This miniseries adds metrics which can help the users detect potential overloads:
* due to having too many in-flight hints
* due to exceeding the capacity of the read admission queue, on replica side
Closes#7584
* github.com:scylladb/scylla:
reader_concurrency_semaphore: add metrics for shed reads
storage_proxy: add metrics for too many in-flight hints failures
When the admission queue capacity reaches its limits, excessive
reads are shed in order to avoid overload. Each such operation
now bumps the metrics, which can help the user judge if a replica
is overloaded.
To facilitate that, keep a const shared_token_metadata& in class database
rather than a const token_metadata&
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
And use it to get a token_metadata& compatible
with current usage, until the services are converted to
use token_metadata_ptr.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Users can change `durable_writes` anytime with ALTER KEYSPACE.
Cassandra reads the value of `durable_writes` every time when applying
a mutation, so changes to that setting take effect immediately. That is,
mutations are added to the commitlog only when `durable_writes` is `true`
at the moment of their application.
Scylla reads the value of `durable_writes` only at `keyspace` construction time,
so changes to that setting take effect only after Scylla is restarted.
This patch fixes the inconsistency.
Fixes#3034Closes#7533
This patch introduces a new system table: `system.scylla_table_schema_history`,
which is used to keep track of column mappings for obsolete table
schema versions (i.e. schema becomes obsolete when it's being changed
by means of `CREATE TABLE` or `ALTER TABLE` DDL operations).
It is populated automatically when a new schema version is being
pulled from a remote in get_schema_definition() at migration_manager.cc
and also when schema change is being propagated to system schema tables
in do_merge_schema() at schema_tables.cc.
The data referring to the most recent table schema version is always
present. Other entries are garbage-collected when the corresponding
table schema version is obsoleted (they will be updated with a TTL equal
to `DEFAULT_GC_GRACE_SECONDS` on `ALTER TABLE`).
In case we failed to persist column mapping after a schema change,
missing entries will be recreated on node boot.
Later, the information from this table is used in `paxos_state::learn`
callback in case we have a mismatch between the most recent schema
version and the one that is stored inside the `frozen_mutation`
for the accepted proposal.
Such situation may arise under following circumstances:
1. The previous LWT operation crashed on the "accept" stage,
leaving behind a stale accepted proposal, which waits to be
repaired.
2. The table affected by LWT operation is being altered, so that
schema version is now different. Stored proposal now references
obsolete schema.
3. LWT query is retried, so that Scylla tries to repair the
unfinished Paxos round and apply the mutation in the learn stage.
When such mismatch happens, prior to that patch the stored
`frozen_mutation` is able to be applied only if we are lucky enough
and column_mapping in the mutation is "compatible" with the new
table schema.
It wouldn't work if, for example, the columns are reordered, or
some columns, which are referenced by an LWT query, are dropped.
With this patch we try to look up the column mapping for
the obsolete schema version, then upgrade the stored mutation
using obtained column mapping and apply an upgraded mutation instead.
* git@github.com:ManManson/scylla.git feature/table_schema_history_v7:
lwt: add column_mapping history persistence tests
schema: add equality operator for `column_mapping` class
lwt: store column_mapping's for each table schema version upon a DDL change
schema_tables: extract `fill_column_info` helper
frozen_mutation: introduce `unfreeze_upgrading` method
This patch introduces a new system table: `system.scylla_table_schema_history`,
which is used to keep track of column mappings for obsolete table
schema versions (i.e. schema becomes obsolete when it's being changed
by means of `CREATE TABLE` or `ALTER TABLE` DDL operations).
It is populated automatically when a new schema version is being
pulled from a remote in get_schema_definition() at migration_manager.cc
and also when schema change is being propagated to system schema tables
in do_merge_schema() at schema_tables.cc.
The data referring to the most recent table schema version is always
present. Other entries are garbage-collected when the corresponding
table schema version is obsoleted (they will be updated with a TTL equal
to `DEFAULT_GC_GRACE_SECONDS` on `ALTER TABLE`).
In case we failed to persist column mapping after a schema change,
missing entries will be recreated on node boot.
Later, the information from this table is used in `paxos_state::learn`
callback in case we have a mismatch between the most recent schema
version and the one that is stored inside the `frozen_mutation`
for the accepted proposal.
Such situation may arise under following circumstances:
1. The previous LWT operation crashed on the "accept" stage,
leaving behind a stale accepted proposal, which waits to be
repaired.
2. The table affected by LWT operation is being altered, so that
schema version is now different. Stored proposal now references
obsolete schema.
3. LWT query is retried, so that Scylla tries to repair the
unfinished Paxos round and apply the mutation in the learn stage.
When such mismatch happens, prior to that patch the stored
`frozen_mutation` is able to be applied only if we are lucky enough
and column_mapping in the mutation is "compatible" with the new
table schema.
It wouldn't work if, for example, the columns are reordered, or
some columns, which are referenced by an LWT query, are dropped.
With this patch we try to look up the column mapping for
the obsolete schema version, then upgrade the stored mutation
using obtained column mapping and apply an upgraded mutation instead.
In case we don't find a column_mapping we just return an error
from the learn stage.
Tests: unit(dev, debug), dtests(paxos_tests.py:TestPaxos.schema_mismatch_*_test)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Require a schema and an operation name to be given to each permit when
created. The schema is of the table the read is executed against, and
the operation name, which is some name identifying the operation the
permit is part of. Ideally this should be different for each site the
permit is created at, to be able to discern not only different kind of
reads, but different code paths the read took.
As not all read can be associated with one schema, the schema is allowed
to be null.
The name will be used for debugging purposes, both for coredump
debugging and runtime logging of permit-related diagnostics.
Allow the evictable reader managing the underlying reader to pass its
own permit to it when creating it, making sure they share the same
permit. Note that the two parts can still end up using different
permits, when the underlying reader is kept alive between two pages of a
paged read and thus keeps using the permit received on the previous
page.
Also adjust the `reader_context` in multishard_mutation_query.cc to use
the passed-in permit instead of creating a new one when creating a new
reader.
Don't create an own permit, take one as a parameter, like all other
readers do, so the permit can be provided by the higher layer, making
sure all parts of the logical read use the same permit.
Although each sstable_directory limits concurrency using
max_concurrent_for_each, there could be a large number
of calls to do_for_each_sstable running in parallel
(e.g per keyspace X per table in the distributed_loader).
To cap parallelism across sstable_directory instances and
concurrent calls to do_for_each_sstable, start a sharded<semaphore>
and pass a shared semaphore& to the sstable_directory:s.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Currently, sstable_manager is used to create sstables, but it loses track
of them immediately afterwards. This series makes an sstable's life fully
contained within its sstable_manager.
The first practical impact (implemented in this series) is that file removal
stops being a background job; instead it is tracked by the sstable_manager,
so when the sstable_manager is stopped, you know that all of its sstable
activity is complete.
Later, we can make use of this to track the data size on disk, but this is not
implemented here.
Closes#7253
* github.com:scylladb/scylla:
sstables: remove background_jobs(), await_background_jobs()
sstables: make sstables_manager take charge of closing sstables
test: test_env: hold sstables_manager with a unique_ptr
test: drop test_sstable_manager
test: sstables::test_env: take ownership of manager
test: broken_sstable_test: prepare for asynchronously closed sstables_manager
test: sstable_utils: close test_env after use
test: sstable_test: dont leak shared_sstable outside its test_env's lifetime
test: sstables::test_env: close self in do_with helpers
test: perf/perf_sstable.hh: prepare for asynchronously closed sstables_manager
test: view_build_test: prepare for asynchronously closed sstables_manager
test: sstable_resharding_test: prepare for asynchronously closed sstables_manager
test: sstable_mutation_test: prepare for asynchronously closed sstables_manager
test: sstable_directory_test: prepare for asynchronously closed sstables_manager
test: sstable_datafile_test: prepare for asynchronously closed sstables_manager
test: sstable_conforms_to_mutation_source_test: remove references to test_sstables_manager
test: sstable_3_x_test: remove test_sstables_manager references
test: schema_changes_test: drop use of test_sstables_manager
mutation_test: adjust for column_family_test_config accepting an sstables_manager
test: lib: sstable_utils: stop using test_sstables_manager
test: sstables test_env: introduce manager() accessor
test: sstables test_env: introduce do_with_async_sharded()
test: sstables test_env: introduce do_with_async_returning()
test: lib: sstable test_env: prepare for life as a sharded<> service
test: schema_changes_test: properly close sstables::test_env
test: sstable_mutation_test: avoid constructing temporary sstables::test_env
test: mutation_reader_test: avoid constructing temporary sstables::test_env
test: sstable_3_x_test: avoid constructing temporary sstables::test_env
test: lib: test_services: pass sstables_manager to column_family_test_config
test: lib: sstables test_env: implement tests_env::manager()
test: sstable_test: detemplate write_and_validate_sst()
test: sstable_test_env: detemplate do_with_async()
test: sstable_datafile_test: drop bad 'return'
table: clear sstable set when stopping
table: prevent table::stop() race with table::query()
database: close sstable_manager:s
sstables_manager: introduce a stub close()
sstable_directory_test: fix threading confusion in make_sstable_directory_for*() functions
test: sstable_datafile_test: reorder table stop in compaction_manager_test
test: view_build_test: test_view_update_generator_register_semaphore_unit_leak: do not discard future in timer
test: view_build_test: fix threading in test_view_update_generator_register_semaphore_unit_leak
view: view_update_generator: drop references to sstables when stopping
Currently all "database" metrics are registered in a single call to
`metric_groups::add_group()`. As all the metrics to-be-registered are
passed in a single initializer list, this blows up the stack size, to
the point that adding a single new metric causes it to exceed the
currently configured max-stack-size of 13696 bytes. To reduce stack
usage, split the single call in two, roughly in the middle. While we
could try to come up with some logical grouping of metrics and do much
arranging and code-movement I think we might as well just split into two
arbitrary groups, containing roughly the same amount of metrics.
In preparations of non-inactive read stats being added to the semaphore,
rename its existing stats struct and member to a more generic name.
Fields, whose name only made sense in the context of the old name are
adjusted accordingly.
The storage service computes gossiper states before it starts the
gossiper. Among them, node's schema version. There are two problems with that.
First is that computing the schema version and publishing it is not
atomic, so is not safe against concurrent schema changes or schema
version recalculations. It will not exclude with
recalculate_schema_version() calls, and we could end up with the old
(and incorrect) schema version being advertised in gossip.
Second problem is that we should not allow the database layer to call
into the gossiper layer before it is fully initialized, as this may
produce undefined behavior.
The solution for both problems is to break the cyclic dependency
between the database layer and the storage_service layer by having the
database layer not use the gossiper at all. The database layer
publishes schema version inside the database class and allows
installing listeners on changes. The storage_service layer asks the
database layer for the current version when it initializes, and only
after that installs a listener which will update the gossiper.
This also allows us to drop unsafe functions like update_schema_version().
"
There's last call for global storage service left in compaction code, it
comes from cleanup_compaction to get local token ranges for filtering.
The call in question is a pure wrapper over database, so this set just
makes use of the database where it's already available (perform_cleanup)
and adds it where it's needed (perform_sstable_upgrade).
tests: unit(dev), nodetool upgradesstables
"
* 'br-remove-ss-from-compaction-3' of https://github.com/xemul/scylla:
storage_service: Remove get_local_ranges helper
compaction: Use database from options to get local ranges
compaction: Keep database reference on upgrade options
compaction: Keep database reference on cleanup options
db: Factor out get_local_ranges helper
Storage service and repair code have identical helpers to get local
ranges for keyspace. Move this helper's code onto database, later it
will be reused by one more place.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
No need to modify token_metadata form database code.
Also, get rid of mutable get_token_metadata variant.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Contains patch from Rafael to fix up includes.
* seastar c872c3408c...7f7cf0f232 (9):
> future: Consider result_unavailable invalid in future_state_base::ignore()
> future: Consider result_unavailable invalid in future_state_base::valid()
> Merge "future-util: split header" from Benny
> docs: corrected some text and code-examples in streaming-rpc docs
> future: Reduce nesting in future::then
> demos: coroutines: include std-compat.hh
> sstring: mark str() and methods using it as noexcept
> tls: Add an assert
> future: fix coroutine compilation
C++17 introduced try_emplace for maps to replace a pattern:
if(element not in a map) {
map.emplace(...)
}
try_emplace is more efficient and results in a more concise code.
This commit introduces usage of try_emplace when it's appropriate.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <4970091ed770e233884633bf6d46111369e7d2dd.1597327358.git.piotr@scylladb.com>
C++20 introduced `contains` member functions for maps and sets for
checking whether an element is present in the collection. Previously
`count` function was often used in various ways.
`contains` does not only express the intend of the code better but also
does it in more unified way.
This commit replaces all the occurences of the `count` with the
`contains`.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <b4ef3b4bc24f49abe04a2aba0ddd946009c9fcb2.1597314640.git.piotr@scylladb.com>
"
This series adds support for the "md" sstable format.
Support is based on the following:
* do not use clustering based filtering in the presence
of static row, tombstones.
* Disabling min/max column names in the metadata for
formats older than "md".
* When updating the metadata, reset and disable min/max
in the presence of range tombstones (like Cassandra does
and until we process them accurately).
* Fix the way we maintain min/max column names by:
keeping whole clustering key prefixes as min/max
rather than calculating min/max independently for
each component, like Cassandra does in the "md" format.
Fixes#4442
Tests: unit(dev), cql_query_test -t test_clustering_filtering* (debug)
md migration_test dtest from git@github.com:bhalevy/scylla-dtest.git migration_test-md-v1
"
* tag 'md-format-v4' of github.com:bhalevy/scylla: (27 commits)
config: enable_sstables_md_format by default
test: cql_query_test: add test_clustering_filtering unit tests
table: filter_sstable_for_reader: allow clustering filtering md-format sstables
table: create_single_key_sstable_reader: emit partition_start/end for empty filtered results
table: filter_sstable_for_reader: adjust to md-format
table: filter_sstable_for_reader: include non-scylla sstables with tombstones
table: filter_sstable_for_reader: do not filter if static column is requested
table: filter_sstable_for_reader: refactor clustering filtering conditional expression
features: add MD_SSTABLE_FORMAT cluster feature
config: add enable_sstables_md_format
database: add set_format_by_config
test: sstable_3_x_test: test both mc and md versions
test: Add support for the "md" format
sstables: mx/writer: use version from sstable for write calls
sstables: mx/writer: update_min_max_components for partition tombstone
sstables: metadata_collector: support min_max_components for range tombstones
sstable: validate_min_max_metadata: drop outdated logic
sstables: rename mc folder to mx
sstables: may_contain_rows: always true for old formats
sstables: add may_contain_rows
...
C++20 introduced `contains` member functions for maps and sets for
checking whether an element is present in the collection. Previously
the code pattern looked like:
<collection>.find(<element>) != <collection>.end()
In C++20 the same can be expressed with:
<collection>.contains(<element>)
This is not only more concise but also expresses the intend of the code
more clearly.
This commit replaces all the occurences of the old pattern with the new
approach.
Tests: unit(dev)
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <f001bbc356224f0c38f06ee2a90fb60a6e8e1980.1597132302.git.piotr@scylladb.com>
"
Make sure to close sstable files also on error paths.
Refs #5509Fixes#6448
Tests: unit (dev)
"
* tag 'sstable-close-files-on-error-v6' of github.com:bhalevy/scylla:
sstable: file_writer: auto-close in destructor
sstable: file_writer: add optional filename member
sstable: add make_component_file_writer
sstable: remove_by_toc_name: accept std::string_view
sstable: remove_by_toc_name: always close file and input stream
sstable: delete_sstables: delete outdated FIXME comment
sstable: remove_by_toc_name: drop error_handler parameter
sstable: remove_by_toc_name: make static
sstable: read_toc: always close file
sstable: mark read_toc and methods calling it noexcept
sstable: read_toc: get rid of file_path
sstable: open_data, create_data: set member only on success.
sstable: open_file: mark as noexcept
sstable: new_sstable_component_file: make noexcept
sstable: new_sstable_component_file: close file on failure
sstable: rename_new_sstable_component_file: do not pass file
sstable: open_sstable_component_file_non_checked: mark as noexcept
sstable: open_integrity_checked_file_dma: make noexcept
sstable: open_integrity_checked_file_dma: close file on failure
MD format is disabled by default at this point.
The option extends enable_sstables_mc_format
so that both are needed to be set for supporting
the md format.
The MD_FORMAT cluster feature will be added in
a following patch.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
This is required for test applications that may select a sstable
format different than the default mc format, like perf_fast_forward.
These apps don't use the gossip-based sstables_format_selector
to set the format based on the cluster feature and so they
need to rely on the db config.
Call set_format_by_config in single_node_cql_env::do_with.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Fixes#6995
In c2c6c71 the assert on replay positions in flushed sstables discarded by
truncate was broken, by the fact that we no longer flush all sstables
unless auto snapshot is enabled.
This means the low_mark assertion does not hold, because we maybe/probably
never got around to creating the sstables that would hold said mark.
Note that the (old) change to not create sstables and then just delete
them is in itself good. But in that case we should not try to verify
the rp mark.
