Nodes automatically ensure that the latest CDC generation's list of
streams is present in the streams description table. When a new
generation appears, we only need to update the table for this
generation; old generations are already inserted.
However, we've changed the description table (from
`cdc_streams_descriptions` to `cdc_streams_descriptions_v2`). The
existing mechanism only ensures that the latest generation appears in
the new description table. This commit adds an additional procedure that
rewrites the older generations as well, if we find that it is necessary
to do so (i.e. when some CDC log tables may contain data in these
generations).
The `query_processor::query` method allowed internal paged queries.
However, it was quite limited, hardcoding a number of parameters:
consistency level, timeout config, page size.
This commit does the following improvements:
1. Rename `query` to `query_internal` to make it obvious that this API
is supposed to be used for internal queries only
2. Extend the method to take consistency level, timeout config, and page
size as parameters
3. Remove unused overloads of `query_internal`
4. Fix a bunch of typos / grammar issues in the docstring
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>
System raft table will be used as a backend storage for implementing
raft persistence module in Scylla. It combines both raft log,
persisted vote and term, and snapshot info.
The table is partitioned by group id, thus allowing multi-raft
operation. The rest of the table structure mirrors the fields of
corresponding core raft structures defined in `raft.hh`, such as
`raft::log_entry`.
The raft table stores the only the latest snapshot id while
the actual snapshot will be available in a separate table
called `system.raft_snapshots`. The schema of `raft_snapshots`
mirrors the fields of `raft::snapshot` structure.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
The save_system_schema and save_system_keyspace_schema are both
called on start and can the needed get query processor reference
from arguments.
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>
The check_help needs global qctx to get db.config.cluster_name,
which is already available at the caller side.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This is the beginning of de-globalizing global qctx thing.
The setup_version() needs global qctx to get config from.
It's possible to get the config from the caller instead.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
There are global db::execute_cql() helpers that just forward
the args into qctx::execute_cql(). The former are going away,
so patch all callers to use qctx themselves.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
THe system_keyspace::minimal_setup is called by main.cc by hands
already, some steps before the regular ::setup().
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The cache_truncation_record needs to run cf.cache_truncation_record
on each shard's DB, so the invoke_on_all can be used.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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>
When the view builder cannot read view building progress from an
internal CQL table it produces an error message, but that only confuses
the user and the test suite -- this situation is entirely recoverable,
because the builder simply assumes that there is no progress and the
view building should start from scratch.
Fixes#7527Closes#7558
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>
There are few places that initialize db and system_ks and need the
messaging service. Pass the reference to it from main instead of
using the global helpers.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Previously system.paxos TTL was set as max(3h, gc_grace_seconds).
Introduce new per-table option named `paxos_grace_seconds` to set
the amount of seconds which are used to TTL data in paxos tables
when using LWT queries against the base table.
Default value is equal to `DEFAULT_GC_GRACE_SECONDS`,
which is 10 days.
This change allows to easily test various issues related to paxos TTL.
Fixes#6284
Tests: unit (dev, debug)
Co-authored-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200816223935.919081-1-pa.solodovnikov@scylladb.com>
Fixes#6341
Since scylla no longer supports upgrading from a version without the
"new" (dedicated) truncation record table, we can remove support for these
and the migtration thereof.
Make sure the above holds whereever this is committed.
Note that this does not remove the "truncated_at" field in
system.local.
"
While working on another patch I was getting odd compiler errors
saying that a call to ::make_shared was ambiguous. The reason was that
seastar has both:
template <typename T, typename... A>
shared_ptr<T> make_shared(A&&... a);
template <typename T>
shared_ptr<T> make_shared(T&& a);
The second variant doesn't exist in std::make_shared.
This series drops the dependency in scylla, so that a future change
can make seastar::make_shared a bit more like std::make_shared.
"
* 'espindola/make_shared' of https://github.com/espindola/scylla:
Everywhere: Explicitly instantiate make_lw_shared
Everywhere: Add a make_shared_schema helper
Everywhere: Explicitly instantiate make_shared
cql3: Add a create_multi_column_relation helper
main: Return a shared_ptr from defer_verbose_shutdown
"
Non-paged queries completely ignore the query result size limiter
mechanism. They consume all the memory they want. With sufficiently
large datasets this can easily lead to a handful or even a single
unpaged query producing an OOM.
This series continues the work started by 134d5a5f7, by introducing a
configurable pair of soft/hard limit (default to 1MB/100MB) that is
applied to otherwise unlimited queries, like reverse and unpaged ones.
When an unlimited query reaches the soft limit a warning is logged. This
should give users some heads-up to adjust their application. When the
hard limit is reached the query is aborted. The idea is to not greet
users with failing queries after an upgrade while at the same time
protect the database from the really bad queries. The hard limit should
be decreased from time to time gradually approaching the desired goal of
1MB.
We don't want to limit internal queries, we trust ourselves to either
use another form of memory usage control, or read only small datasets.
So the limit is selected according to the query class. User reads use
the `max_memory_for_unlimited_query_{soft,hard}_limit` configuration
items, while internal reads are not limited. The limit is obtained by
the coordinator, who passes it down to replicas using the existing
`max_result_size` parameter (which is not a special type containing the
two limits), which is now passed on every verb, instead of once per
connection. This ensures that all replicas work with the same limits.
For normal paged queries `max_result_size` is set to the usual
`query::result_memory_limiter::maximum_result_size` For queries that can
consume unlimited amount of memory -- unpaged and reverse queries --
this is set to the value of the aforementioned
`max_memory_for_unlimited_query_{soft,hard}_limit` configuration item,
but only for user reads, internal reads are not limited.
This has the side-effect that reverse reads now send entire
partitions in a single page, but this is not that bad. The data was
already read, and its size was below the limit, the replica might as well
send it all.
Fixes: #5870
"
* 'nonpaged-query-limit/v5' of https://github.com/denesb/scylla: (26 commits)
test: database_test: add test for enforced max result limit
mutation_partition: abort read when hard limit is exceeded for non-paged reads
query-result.hh: move the definition of short_read to the top
test: cql_test_env: set the max_memory_unlimited_query_{soft,hard}_limit
test: set the allow_short_read slice option for paged queries
partition_slice_builder: add with_option()
result_memory_accounter: remove default constructor
query_*(): use the coordinator specified memory limit for unlimited queries
storage_proxy: use read_command::max_result_size to pass max result size around
query: result_memory_limiter: use the new max_result_size type
query: read_command: add max_result_size
query: read_command: use tagged ints for limit ctor params
query: read_command: add separate convenience constructor
service: query_pager: set the allow_short_read flag
result_memory_accounter: check(): use _maximum_result_size instead of hardcoded limit
storage_proxy: add get_max_result_size()
result_memory_limiter: add unlimited_result_size constant
database: add get_statement_scheduling_group()
database: query_mutations(): obtain the memory accounter inside
query: query_class_config: use max_result_size for the max_memory_for_unlimited_query field
...
This field will replace max size which is currently passed once per
established rpc connection via the CLIENT_ID verb and stored as an
auxiliary value on the client_info. For now it is unused, but we update
all sites creating a read command to pass the correct value to it. In the
next patch we will phase out the old max size and use this field to pass
max size on each verb instead.
The convenience constructor of read_command now has two integer
parameter next to each other. In the next patch we intend to add another
one. This is recipe for disaster, so to avoid mistakes this patch
converts these parameters to tagged integers. This makes sure callers
pass what they meant to pass. As a matter of fact, while fixing up
call-sites, I already found several ones passing `query::max_partitions`
to the `row_limit` parameter. No harm done yet, as
`query::max_partitions` == `query::max_rows` but this shows just how
easy it is to mix up parameters with the same type.
Currently, encountering an error when loading view build progress
would result in view builder refusing to start - which also means
that future views would not be built until the server restarts.
A more user-friendly solution would be to log an error message,
but continue to boot the view builder as if no views are currently
in progress, which would at least allow future views to be built
correctly.
The test case is also amended, since now it expects the call
to return that "no view builds are in progress" instead of
an exception.
Fixes#6934
Tests: unit(dev)
Message-Id: <9f26de941d10e6654883a919fd43426066cee89c.1595922374.git.sarna@scylladb.com>
seastar::make_lw_shared has a constructor taking a T&&. There is no
such constructor in std::make_shared:
https://en.cppreference.com/w/cpp/memory/shared_ptr/make_shared
This means that we have to move from
make_lw_shared(T(...)
to
make_lw_shared<T>(...)
If we don't want to depend on the idiosyncrasies of
seastar::make_lw_shared.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
This replaces a lot of make_lw_shared(schema(...)) with
make_shared_schema(...).
This makes it easier to drop a dependency on the differences between
seastar::make_shared and std::make_shared.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
We'd like to use the same uuid both for printing compaction log
messages and to update compaction_history.
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
We were not consistent about using '#include "foo.hh"' instead of
'#include <foo.hh>' for scylla's own headers. This patch fixes that
inconsistency and, to enforce it, changes the build to use -iquote
instead of -I to find those headers.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Message-Id: <20200608214208.110216-1-espindola@scylladb.com>
This is purely utility helper routine. As a nice side effect the
inclusion of storage_service.hh is removed from several unrelated
places.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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.
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`.
Local system tables from `system` namespace use LocalStrategy
replication, so they do not need to be concerned about gc grace
period. Some system tables already set gc grace period to 0,
but other ones, including system.large_partitions, did not.
That may result in millions of tombstones being needlessly
kept for these tables, which can cause read timeouts.
Fixes#6325
Tests: unit(dev), local(running cqlsh and playing with system tables)
Some caller have partition_key_view, but not partition_key, so thy need
to create a temporary and copy just to pass a reference. Change it by
accepting a view.
It turned out we cannot drop the information about most recent commit
entirely since it is used to cut off already outdate accepted values.
Otherwise the following scenario can happen:
1. cas1 prepares on A, B, C, gets one accept from A
2. cas2 prepares on B, C, gets 2 accepts on B and C, learns on B, C
3. cas3 initiates a prepare on A, learns about cas1's accept,
4. cas2 learns on A, prunes on A, B, C
Now cas3 will reply cas1's value because it does not know that it is
less than already committed on (removed during step 4).
The patch drops only committed value and keep the information about
latest committed ballot.
Fixed#6154
PAXOS node is allowed to accept a proposal without promising it
first as long as its ballot is greater than already promised one. Treat
such accepted ballot as promised since 'learn' stage removes accepted
ballot, but we still want to remember it as the latest promised one.
The goal is to be closer to formal PAXOS specification.
The learning stage of PAXOS protocol leaves behind an entry in
system.paxos table with the last learned value (which can be large). In
case not all participants learned it successfully next round on the same
key may complete the learning using this info. But if all nodes learned
the value the entry does not serve useful purpose any longer.
The patch adds another round, "prune", which is executed in background
(limited to 1000 simultaneous instances) and removes the entry in
case all nodes replied successfully to the "learn" round. It uses the
ballot's timestamp to do the deletion, so not to interfere with the
next round. Since deletion happens very close to previous writes it will
likely happen in memtable and will never reach sstable, so that reduces
memtable flush and compaction overhead.
Fixes#5779
Message-Id: <20200330154853.GA31074@scylladb.com>
The value that is stored in "in_progress_ballot" cell is the value of
promised ballot, so call the cell accordingly to avoid confusion
especially as we have a notion of "in progress" proposal in the code
which is not the same as in_progress_ballot here.
We can still do it without care about backwards compatibility since LWT
is still marked as experimental.
Fixes#6087.
Message-Id: <20200326095758.GA10219@scylladb.com>
The function in question uses future-based .when_enabled() subscription
on cluster_supports_truncation_table feature. This method is considered
to be unsafe, so here's the patch that changes it onto feature::listener.
The completion of the migration is only awaited by a single test, so
this waiting mechanism is also slightly simplified.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This wrapper just makes sure the system_keyspace::get_saved_tokens
reports non empty result. Move them close together.
As a side effect -- get rid of penultimate global storage_service
reference from size_estimates_virtual_reader (the last one will
be removed soon).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
"
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
