Commit Graph

120 Commits

Author SHA1 Message Date
Marcin Maliszkiewicz
32fe101f9d db: replica: batch functions schema modifications
Before each function change was immediately visible as
during event notification logic yielded.

Now we first gather the modifications and then commit them.

Further work will broaden the scope of atomicity to the whole
schema and even across other subsystems.
2024-07-04 13:10:26 +02:00
Kefu Chai
ad649be1bf treewide: drop thrift support
thrift support was deprecated since ScyllaDB 5.2

> Thrift API - legacy ScyllaDB (and Apache Cassandra) API is
> deprecated and will be removed in followup release. Thrift has
> been disabled by default.

so let's drop it. in this change,

* thrift protocol support is dropped
* all references to thrift support in document are dropped
* the "thrift_version" column in system.local table is
  preserved for backward compatibility, as we could load
  from an existing system.local table which still contains
  this clolumn, so we need to write this column as well.
* "/storage_service/rpc_server" is only preserved for
  backward compatibility with java-based nodetool.
* `rpc_port` and `start_rpc` options are preserved, but
  they are marked as "Unused". so that the new release
  of scylladb can consume existing scylla.yaml configurations
  which might contain these settings. by making them
  deprecated, user will be able get warned, and update
  their configurations before we actually remove them
  in the next major release.

Fixes #3811
Fixes #18416
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2024-06-07 06:44:59 +08:00
Michał Jadwiszczak
3830f3bd23 db/cql_type_parses: futurize raw_builder::build()
In order to use generic topological sort,
build() method needs to return future.
2024-05-16 13:30:03 +02:00
Avi Kivity
4ddf82e58b treewide: don't #include "gms/feature_service.hh" from other headers
feature_service.hh is a high-level header that integrates much
of the system functionality, so including it in lower-level headers
causes unnecessary rebuilds. Specifically, when retiring features.

Fix by removing feature_service.hh from headers, and supply forward
declarations and includes in .cc where needed.

Closes scylladb/scylladb#18005
2024-03-26 15:31:18 +02:00
Kefu Chai
be364d30fd db: do not include unused headers
these unused includes were identified by clangd. see
https://clangd.llvm.org/guides/include-cleaner#unused-include-warning
for more details on the "Unused include" warning.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>

Closes scylladb/scylladb#16664
2024-01-09 11:44:19 +02:00
Kefu Chai
15bfa09454 treewide: do not mark return value const if this has no effect
this change is a cleanup.

to mark a return value without value semantics has no effect. these
`const` specifier useless. so let's drop them.

and, if we compile the tree with `-Wignore-qualifiers`, the compiler
would warn like:

```
/home/kefu/dev/scylladb/schema/schema.hh:245:5: error: 'const' type qualifier on return type has no effect [-Werror,-Wignored-qualifiers]
  245 |     const index_metadata_kind kind() const;
      |     ^~~~~
```
so this change also silences the above warnings.

Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
2023-11-17 17:46:19 +08:00
Kamil Braun
3976808b12 schema_tables: turn view schema fixing code into a sanity check
The purpose of `maybe_fix_legacy_secondary_index_mv_schema` was to deal
with legacy materialized view schemas used for secondary indexes,
schemas which were created before the notion of "computed columns" was
introduced. Back then, secondary index schemas would use a regular
"token" column. Later it became a computed column and old schemas would
be migrated during rolling upgrade.

The migration code was introduced in 2019
(db8d4a0cc6) and then fixed in 2020
(d473bc9b06).

The fix was present in Enterprise 2022.1 and in OSS 4.5. So, assuming
that users don't try crazy things like upgrading from 2021.X to 2023.X
(which we do not support), all clusters will have already executed the
migration code once they upgrade to 2023.X, meaning we can get rid of
it.

The main motivation of this patch is to get rid of the
`db::schema_tables::merge_schema` call in `parse_schema_tables`. In Raft
mode this was the only call to `merge_schema` outside "group 0 code" and
in fact it is unsafe -- it uses locally generated mutations with locally
generated timestamp (`api::new_timestamp()`), so if we actually did it,
we would permanently diverge the group 0 state machine across nodes
(the schema pulling code is disabled in Raft mode). Fortunately, this
should be dead code by now, as explained in the previous paragraph.

The migration code is now turned into a sanity check, if the users
try something crazy, they will get an error instead of silent data
corruption.
2023-10-24 13:33:35 +02:00
Avi Kivity
35849fc901 Revert "Merge 'Don't calculate hashes for schema versions in Raft mode' from Kamil Braun"
This reverts commit 3d4398d1b2, reversing
changes made to 45dfce6632. The commit
causes some schema changes to be lost due to incorrect timestamps
in some mutations. More information is available in [1].

Reopens: scylladb/scylladb#7620
Reopens: scylladb/scylladb#13957

Fixes scylladb/scylladb#15530.

[1] https://github.com/scylladb/scylladb/pull/15687
2023-10-11 00:32:05 +03:00
Kamil Braun
4376854473 schema_tables: remove default value for reload in merge_schema
To avoid bugs like the one fixed in the previous commit.
2023-09-15 13:04:04 +02:00
Petr Gusev
f0bc9f2d93 system_keyspace: refactor save_system_schema function
This is a refactoring commit without observable changes
in behaviour.

Previously, there were two related functions in db::schema_tables:
save_system_keyspace_schema(qp) and save_system_schema(qp, ks).
The first called the second passing "system_schema" as
the second argument. Outside of schema_tables module we
don't need two functions, we just need a way to say
'persist system schema objects in the appropriate tables/keyspaces'.
In this commit we change the function save_system_schema
to have this meaning. Internally it calls save_system_schema_to_keyspace
twice with "system_schema" and "system", since that's what we need
in the single call site of this function in system_keyspace::setup.
In subsequent commits we are going to move this call out of the
system_keyspace::setup.
2023-09-13 23:00:15 +04:00
Botond Dénes
72043a6335 Merge 'Avoid using qctx in schema_tables' column-mapping queries' from Pavel Emelyanov
There are three methods in system_keyspace namespace that run queries over `system.scylla_table_schema_history` table. For that they use qctx which's not nice.

Fortunately, all the callers already have the system_keyspace& local variable or argument they can pass to those methods. Since the accessed table belongs to system keyspace, the latter declares the querying methods as "friends" to let them get private `query_processor& _qp` member

Closes #14876

* github.com:scylladb/scylladb:
  schema_tables: Extract query_processor from system_keyspace for querying
  schema_tables: Add system_keyspace& argument to ..._column_mapping() calls
  migration_manager: Add system_keyspace argument to get_schema_mapping()
2023-07-31 15:00:59 +03:00
Pavel Emelyanov
cf4d4d7e9b schema_tables: Add system_keyspace& argument to ..._column_mapping() calls
The callers all have local sys_ks argument:

- merge_tables_and_views()
- service::get_column_mapping()
- database::parse_system_tables()

And a test that can get it from cql_test_env.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2023-07-28 15:55:13 +03:00
Tomasz Grabiec
f2ed9fcd7e schema_mutations, migration_manager: Ignore empty partitions in per-table digest
Schema digest is calculated by querying for mutations of all schema
tables, then compacting them so that all tombstones in them are
dropped. However, even if the mutation becomes empty after compaction,
we still feed its partition key. If the same mutations were compacted
prior to the query, because the tombstones expire, we won't get any
mutation at all and won't feed the partition key. So schema digest
will change once an empty partition of some schema table is compacted
away.

Tombstones expire 7 days after schema change which introduces them. If
one of the nodes is restarted after that, it will compute a different
table schema digest on boot. This may cause performance problems. When
sending a request from coordinator to replica, the replica needs
schema_ptr of exact schema version request by the coordinator. If it
doesn't know that version, it will request it from the coordinator and
perform a full schema merge. This adds latency to every such request.
Schema versions which are not referenced are currently kept in cache
for only 1 second, so if request flow has low-enough rate, this
situation results in perpetual schema pulls.

After ae8d2a550d, it is more liekly to
run into this situation, because table creation generates tombstones
for all schema tables relevant to the table, even the ones which
will be otherwise empty for the new table (e.g. computed_columns).

This change inroduces a cluster feature which when enabled will change
digest calculation to be insensitive to expiry by ignoring empty
partitions in digest calculation. When the feature is enabled,
schema_ptrs are reloaded so that the window of discrepancy during
transition is short and no rolling restart is required.

A similar problem was fixed for per-node digest calculation in
18f484cc753d17d1e3658bcb5c73ed8f319d32e8. Per-table digest calculation
was not fixed at that time because we didn't persist enabled features
and they were not enabled early-enough on boot for us to depend on
them in digest calculation. Now they are enabled before non-system
tables are loaded so digest calculation can rely on cluster features.

Fixes #4485.
2023-07-03 23:06:55 +02:00
Tomasz Grabiec
0c86abab4d migration_manager, schema_tables: Implement migration_manager::reload_schema()
Will recreate schema_ptr's from schema tables like during table
alter. Will be needed when digest calculation changes in reaction to
cluster feature at run time.
2023-07-03 20:32:59 +02:00
Tomasz Grabiec
2303466375 db: schema: Attach table pointer to schema
This will make it easier to access table proprties in places which
only have schema_ptr. This is in particular useful when replacing
dht::shard_of() uses with s->table().shard_of(), now that sharding is
no longer static, but table-specific.

Also, it allows us to install a guard which catches invalid uses of
schema::get_sharder() on tablet-based tables.

It will be helpful for other uses as well. For example, we can now get
rid of the static_props hack.
2023-06-21 00:58:24 +02:00
Botond Dénes
63b266a988 db/schema_tables: expose types schema 2023-04-12 02:43:53 -04:00
Botond Dénes
54c0a387a2 Revert "Merge 'tool/scylla-sstable: more flexibility in obtaining the schema' from Botond Dénes"
This reverts commit 32fff17e19, reversing
changes made to 164afe14ad.

This series proved to be problematic, the new test introduced by it
failing quite often. Revert it until the problems are tracked down and
fixed.
2023-04-03 13:54:00 +03:00
Botond Dénes
132d101dc7 db/schema_tables: expose types schema 2023-03-24 08:50:39 -04:00
Wojciech Mitros
4609a45ce3 wasm: convert compilation to a future
After we move the compilation to a alien thread, the completion
of the compilation will be signaled by fulfilling a seastar promise.
As a result, the `precompile` function will return a future, and
because of that, other functions that use the `precompile` functions
will also become futures.
We can do all the neccessary adjustments beforehand, so that the actual
patch that moves the compilation will contain less irrelevant changes.
2023-03-07 14:27:38 +01:00
Avi Kivity
e2f6e0b848 utils: move hashing related files to utils/ module
Closes #12884
2023-02-17 07:19:52 +02:00
Avi Kivity
69a385fd9d Introduce schema/ module
Schema related files are moved there. This excludes schema files that
also interact with mutations, because the mutation module depends on
the schema. Those files will have to go into a separate module.

Closes #12858
2023-02-15 11:01:50 +02:00
Avi Kivity
c5e4bf51bd Introduce mutation/ module
Move mutation-related files to a new mutation/ directory. The names
are kept in the global namespace to reduce churn; the names are
unambiguous in any case.

mutation_reader remains in the readers/ module.

mutation_partition_v2.cc was missing from CMakeLists.txt; it's added in this
patch.

This is a step forward towards librarization or modularization of the
source base.

Closes #12788
2023-02-14 11:19:03 +02:00
Wojciech Mitros
e558c7d988 functions: initialize aggregates on scylla start
Currently, UDAs can't be reused if Scylla has been
restarted since they have been created. This is
caused by the missing initialization of saved
UDAs that should have inserted them to the
cql3::functions::functions::_declared map, that
should store all (user-)created functions and
aggregates.

This patch adds the missing implementation in a way
that's analogous to the method of inserting UDF to
the _declared map.

Fixes #11309
2023-01-10 17:44:18 +02:00
Benny Halevy
2b017ce285 schema, everywhere: define and use table_schema_version as a strong type
Define table_schema_version as a distinct tagged_uuid class,
So it can be differentiated from other uuid-class types,
in particular table_id.

Added reversed(table_schema_version) for convenience
and uniformity since the same logic is currently open coded
in several places.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-08-08 08:09:45 +03:00
Benny Halevy
257d74bb34 schema, everywhere: define and use table_id as a strong type
Define table_id as a distinct utils::tagged_uuid modeled after raft
tagged_id, so it can be differentiated from other uuid-class types,
in particular from table_schema_version.

Fixes #11207

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2022-08-08 08:09:41 +03:00
Jadw1
d13f347621 DB: Add scylla_aggregates system table
Saving information about UDA's reduce function to `scylla_aggregates`
table and distributing it across cluster.
2022-07-18 15:25:37 +02:00
Tomasz Grabiec
6b316f267f db: Avoid memtable flush latency on schema merge
Currently, applying schema mutations involves flushing all schema
tables so that on restart commit log replay is performed on top of
latest schema (for correctness). The downside is that schema merge is
very sensitive to fdatasync latency. Flushing a single memtable
involves many syncs, and we flush several of them. It was observed to
take as long as 30 seconds on GCE disks under some conditions.

This patch changes the schema merge to rely on a separate commit log
to replay the mutations on restart. This way it doesn't have to wait
for memtables to be flushed. It has to wait for the commitlog to be
synced, but this cost is well amortized.

We put the mutations into a separate commit log so that schema can be
recovered before replaying user mutations. This is necessary because
regular writes have a dependency on schema version, and replaying on
top of latest schema satisfies all dependencies. Without this, we
could get loss of writes if we replay a write which depends on the
latest schema on top of old schema.

Also, if we have a separate commit log for schema we can delay schema
parsing for after the replay and avoid complexity of recognizing
schema transactions in the log and invoking the schema merge logic.

One complication with this change is that replay_position markers are
commitlog-domain specific and cannot cross domains. They are recorded
in various places which survive node restart: sstables are annotated
with the maximum replay position, and they are present inside
truncation records. The former annotation is used by "truncate"
operation to drop sstables. To prevent old replay positions from being
interpreted in the context in the new schema commitlog domain, the
change refuses to boot if there are truncation records, and also
prohibits truncation of schema tables.

The boot sequence needs to know whether the cluster feature associated
with this change was enabled on all nodes. Fetaures are stored in
system.scylla_local. Because we need to read it before initializing
schema tables, the initialization of tables now has to be split into
two phases. The first phase initializes all system tables except
schema tables, and later we initialize schema tables, after reading
stored cluster features.

The commitlog domain is switched only when all nodes are upgraded, and
only after new node is restarted. This is so that we don't have to add
risky code to deal with hot-switching of the commitlog domain. Cold
switching is safer. This means that after upgrade there is a need for
yet another rolling restart round.

Fixes #8272
Fixes #8309
Fixes #1459
2022-07-06 22:08:56 +02:00
Avi Kivity
5937b1fa23 treewide: remove empty comments in top-of-files
After fcb8d040 ("treewide: use Software Package Data Exchange
(SPDX) license identifiers"), many dual-licensed files were
left with empty comments on top. Remove them to avoid visual
noise.

Closes #10562
2022-05-13 07:11:58 +02:00
Pavel Emelyanov
0f698910e8 cql_type_parser: Require user_types_storage& in parse()
Right now to get user types the method in question gets global proxy
instance to get database from it and then peek a keyspace, its metadata
and, finally, the user types. There's also a safety check for proxy not
being initialized, which happens in tests.

Instead of messing with the proxy, the parse() method now accepts the
user_types_storage reference from which it gets the types. All the
callers already have the needed storage at hand -- in most of the cases
it's one shared between the database and schema_ctxt. In case of tests
is's a dummy storage, in case of schema-loader it's its local one.

The get_column_mapping() is special -- it doesn't expect any user-types
to be parsed and passes "" keyspace into it, neither it has db/ctxt to
get types storage from, so it can safely use the dummy one.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-05-05 13:11:18 +03:00
Pavel Emelyanov
2104d90dd0 user_types: Carry storage on database and schema_ctxt
The user types storage is needed in cql_type_parser::parse which is in
turn called with either replica::database or scema_ctxt at hand.

To facilitate the former case replica::database has its own user types
storage created in database constructor.

The latter case is a bit trickier. In many cases the ctxt is created as
a temporary object and the database is available at those places. Also
the ctxt object lives on the schema_registry instance which doesn't have
database nearby. However, that ctxt lifetime is the same as the registry
instance one and when it's created there's a database at hand (it's the
database constructor that calls schema_registry.init() passing "this"
into it). Thus, the solution is to make database's user types storage be
a shared pointer that's shared between database itself and all the ctxts
out there including the one that lives on schema_registry instance.

When database goes away it .deactivate()s its user types storage so that
any ctxts that may share it stay on the safe side and don't use database
after free. This part will go away when the schema_registry will be
deglobalized.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-05-05 13:06:04 +03:00
Avi Kivity
de0ee13f45 schema_tables: forward-declare user_function and user_aggerates
These bring in wasm.hh (though they really shouldn't) and make
everyone suffer. Forward declare instead and add missing includes
where needed.

Closes #10444
2022-04-28 07:22:02 +03:00
Piotr Sarna
58529591a9 database,cql3: add STORAGE option to keyspaces
The STORAGE option is designed to hold a map of options
used for customizing storage for given keyspace.
The option is kept in a system_schema.scylla_keyspaces table.
The option is only available if the whole cluster is aware
of it - guarded by a cluster feature.

Example of the table contents:
```
cassandra@cqlsh> select * from system_schema.scylla_keyspaces;

 keyspace_name | storage_options                                | storage_type
---------------+------------------------------------------------+--------------
           ksx | {'bucket': '/tmp/xx', 'endpoint': 'localhost'} |           S3
```
2022-04-08 09:17:01 +02:00
Pavel Emelyanov
b80d5f8900 schema_tables: Add sharded<system_keyspace> argument to update_schema_version_and_announce
All its (indirect) callers had been patched to have it, now it's
possible to have the argument in it. Next patch will make use of it

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
2022-03-16 14:24:40 +03:00
Nadav Har'El
7be3129458 cdc: don't need current keyspace to create the log table
CDC registers to the table-creation hook (before_create_column_family)
to add a second table - the CDC log table - to the same keyspace.
The handler function (on_before_update_column_family() in cdc/log.cc)
wants to retrieve the keyspace's definition, but that does NOT WORK if
we create the keyspace and table in one operation (which is exactly what
we intend to do in Alternator to solve issue #9868) - because at the
time of the hook, the keyspace does not yet exist in the schema.

It turns out that on_before_update_column_family() does not REALLY need
the keyspace. It needed it to pass it on to make_create_table_mutations()
but that function doesn't use the keyspace parameter passed to it! All
it needs is the keyspace's name - which is in the schema anyway and
doesn't need to be looked up.

So in this patch we fix make_create_table_mutations() to not require the
unused keyspace parameter - and fix the CDC code not to look for the
keyspace that is no longer needed.

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20220215162342.622509-1-nyh@scylladb.com>
2022-02-16 08:38:56 +02:00
Avi Kivity
fcb8d040e8 treewide: use Software Package Data Exchange (SPDX) license identifiers
Instead of lengthy blurbs, switch to single-line, machine-readable
standardized (https://spdx.dev) license identifiers. The Linux kernel
switched long ago, so there is strong precedent.

Three cases are handled: AGPL-only, Apache-only, and dual licensed.
For the latter case, I chose (AGPL-3.0-or-later and Apache-2.0),
reasoning that our changes are extensive enough to apply our license.

The changes we applied mechanically with a script, except to
licenses/README.md.

Closes #9937
2022-01-18 12:15:18 +01:00
Avi Kivity
bbad8f4677 replica: move ::database, ::keyspace, and ::table to replica namespace
Move replica-oriented classes to the replica namespace. The main
classes moved are ::database, ::keyspace, and ::table, but a few
ancillary classes are also moved. There are certainly classes that
should be moved but aren't (like distributed_loader) but we have
to start somewhere.

References are adjusted treewide. In many cases, it is obvious that
a call site should not access the replica (but the data_dictionary
instead), but that is left for separate work.

scylla-gdb.py is adjusted to look for both the new and old names.
2022-01-07 12:04:38 +02:00
Avi Kivity
3945acaa2d data_dictionary: move keyspace_metadata to data_dictionary
Like user_types_metadata, keyspace_metadata does not grant
data access, just metadata, and so belongs in data_dictionary.
2021-12-15 13:52:21 +02:00
Benny Halevy
3393df45eb token_metadata, storage_service: unify token_metadata_lock and merge_lock.
Serialize the metadata changes with
keyspace create, update, or drop.

This will become necessary in the following patch
when we update the effective_replication_map
on all keyspaces and we want instances on all shards
end up with the same replication map.

Note that storage_service::keyspace_changed is called
from the scheme_merge path so it already holds
the merge_lock.

Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
2021-10-13 13:01:25 +03:00
Piotr Sarna
84876a165b db,schema_tables: add handling user-defined aggregates
Aggregates are propagated, created and dropped very similarly
to user-defined functions - a set of helper functions
for aggregates are added based on the UDF implementation.
2021-08-13 11:14:11 +02:00
Avi Kivity
3b5e312800 db: schema_tables: clean up read_schema_partition_for_keyspace() coroutine captures
read_schema_partition_for_keyspace() copies some parameters to capture them
in a coroutine, but the same can be achieved more cleanly by changing the
reference parameters to value parameters, so do that.

Test: unit (dev)

Closes #9154
2021-08-08 12:55:10 +03:00
Avi Kivity
a55b434a2b treewide: extent copyright statements to present day 2021-06-06 19:18:49 +03:00
Nadav Har'El
58e275e362 cross-tree: reduce dependency on db/config.hh and database.hh
Every time db/config.hh is modified (e.g., to add a new configuration
option), 110 source files need to be recompiled. Many of those 110 didn't
really care about configuration options, and just got the dependency
accidentally by including some other header file.

In this patch, I remove the include of "db/config.hh" from all header
files. It is only needed in source files - and header files only
need forward declarations. In some cases, source files were missing
certain includes which they got incidentally from db/config.hh, so I
had to add these includes explicitly.

After this patch, the number of source files that get recompiled after a
change to db/config.hh goes down from 110 to 45.
It also means that 65 source files now compile faster because they don't
include db/config.hh and whatever it included.

Additionally, this patch also eliminates a few unnecessary inclusions
of database.hh in other header files, which can use a forward declaration
or database_fwd.hh. Some of the source files including one of those
header files relied on one of the many header files brought in by
database.hh, so we need to include those explicitly.
In view_update_generator.hh something interesting happened - it *needs*
database.hh because of code in the header file, but only included
database_fwd.hh, and the only reason this worked was that the files
including view_update_generator.hh already happened to unnecessarily
include database.hh. So we fix that too.

Refs #1

Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210505102111.955470-1-nyh@scylladb.com>
2021-05-05 13:23:00 +03:00
Avi Kivity
daeddda7cc treewide: remove inclusions of storage_proxy.hh from headers
storage_proxy.hh is huge and includes many headers itself, so
remove its inclusions from headers and re-add smaller headers
where needed (and storage_proxy.hh itself in source files that
need it).

Ref #1.
2021-04-20 21:23:00 +03:00
Eliran Sinvani
39cd9dae4e materialized views: Extract fix legacy schema into its own logic
We extract the logic for fixing the view schema into it's own
logic as we will need to use it in more places in the code.
This makes 'maybe_update_legacy_secondary_index_mv_schema' redundant since
it becomes a two liner wrapper for this logic. We also
remove it here and replace the call to it with the equivalent code.
2021-03-07 12:50:42 +02:00
Pavel Emelyanov
9632af5d6b schema_tables: Drop unused merge_schema overload
After the d3aa1759 one of them became unused.

Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210105051724.5249-1-xemul@scylladb.com>
2021-01-05 11:25:22 +02:00
Piotr Sarna
d5da455d95 schema_tables: describe calculate_schema_digest better
- the mystical `accept_predicate` is renamed to `accept_keyspace`
   to be more self-descriptive
 - a short comment is added to the original calculate_schema_digest
   function header, mentioning that it computes schema digest
   for non-system keyspaces

Refs #7854

Message-Id: <04f1435952940c64afd223bd10a315c3681b1bef.1609763443.git.sarna@scylladb.com>
2021-01-04 14:46:17 +02:00
Piotr Sarna
13a60b02ea schema_tables: allow custom predicates in schema digest calc
For testing purposes it would be useful to be able to skip computing
schema for certain tables (namely, internal distributed tables).
In order to allow that, a function which accepts a custom predicate
is added.
2021-01-04 10:11:41 +01:00
Pavel Emelyanov
89fd524c5a schema-tables: Add database argument to make_update_table_mutations
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>
2020-12-11 21:21:22 +03:00
Pavel Emelyanov
464c8990d4 schema-tables: Use query processor referece in save_system(_keyspace)?_schema
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>
2020-11-19 18:39:05 +03:00
Tomasz Grabiec
f893516e55 Merge "lwt: store column_mapping's for each table schema version upon a DDL change" from Pavel Solodovnikov
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
2020-10-15 20:48:29 +02:00