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
The database, keyspace, and table classes represent the replica-only
part of the objects after which they are named. Reading from a table
doesn't give you the full data, just the replica's view, and it is not
consistent since reconciliation is applied on the coordinator.
As a first step in acknowledging this, move the related files to
a replica/ subdirectory.
The gc_grace_seconds is a very fragile and broken design inherited from
Cassandra. Deleted data can be resurrected if cluster wide repair is not
performed within gc_grace_seconds. This design pushes the job of making
the database consistency to the user. In practice, it is very hard to
guarantee repair is performed within gc_grace_seconds all the time. For
example, repair workload has the lowest priority in the system which can
be slowed down by the higher priority workload, so that there is no
guarantee when a repair can finish. A gc_grace_seconds value that is
used to work might not work after data volume grows in a cluster. Users
might want to avoid running repair during a specific period where
latency is the top priority for their business.
To solve this problem, an automatic mechanism to protect data
resurrection is proposed and implemented. The main idea is to remove the
tombstone only after the range that covers the tombstone is repaired.
In this patch, a new table option tombstone_gc is added. The option is
used to configure tombstone gc mode. For example:
1) GC a tombstone after gc_grace_seconds
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'timeout'} ;
This is the default mode. If no tombstone_gc option is specified by the
user. The old gc_grace_seconds based gc will be used.
2) Never GC a tombstone
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'disabled'};
3) GC a tombstone immediately
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'immediate'};
4) GC a tombstone after repair
cqlsh> ALTER TABLE ks.cf WITH tombstone_gc = {'mode':'repair'};
In addition to the 'mode' option, another option 'propagation_delay_in_seconds'
is added. It defines the max time a write could possibly delay before it
eventually arrives at a node.
A new gossip feature TOMBSTONE_GC_OPTIONS is added. The new tombstone_gc
option can only be used after the whole cluster supports the new
feature. A mixed cluster works with no problem.
Tests: compaction_test.py, ninja test
Fixes#3560
[avi: resolve conflicts vs data_dictionary]
make_shared_schema() is often used to create a schema that is then
passed to schema_builder to modify it further. This is wasteful as the
schema is built just to be disassembled and rebuilt again. To replace
this wasteful pattern we provide a schema_builder constructor that has
the same signature as `make_shared_schema()`, allowing follow-up
modifications on the schema before it is fully built.
We use a custom sharder for all schema tables: every table under
the `system_schema` keyspace, plus `system.scylla_table_schema_history`.
This sharder puts all data on shard 0.
To achieve this, we hardcode the sharder in initial schema object
definitions. Furthermore - since the sharder is not stored inside schema
mutations yet - whenever we deserialize schema objects from mutations,
we modify the sharder based on the schema's keyspace and table names.
A regression test is added to ensure no one forgets to set the special
sharder for newly added schema tables. This test assumes that all newly
added schema tables will end up in the `system_schema` keyspace (other
tables may go unnoticed, unfortunately).
Closes#7947
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>
In order to avoid confusion with regard to whose responsibility
it is to sort the key columns (see #5856), the interface which allows
adding columns to the builder with explicit column id
is moved to a private function. An internal with_column_ordered()
overload is maintained to be used for internal operations,
but it's encouraged to use simpler with_column() in new code.
Fixes#6235
Tests: unit(dev)
Previously schema::get_sharding_info was obtaining
sharding_info from the partitioner but we want to remove
sharding_info from the partitioner so we need a place
in schema to store it there instead.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
After previous patches that switched some tests to use sharding_info
instead of i_partitioner, we now don't need with_partitioner_for_tests_only
and the function can be removed.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
"
This PR makes it possible to enable the usage of different partitioner for each table. If no table-specific partitioner is set for a given table then a default partitioner is used.
The PR is composed of the following parts:
- Introduction of schema::get_partitioner that still returns dht::global_partitioner
- Replacement of all the usage of dht::global_partitioner with schema::get_partitioner
- Making it possible to set table-specific partitioner in a schema_builder
- Remove all the places that were setting default partitioner except for main.cc (mostly tests)
- Move default partitioner from i_partitioner to schema.cc and hide it from the rest of the codebase
- Remove dht::global_partitioner
After this PR there's no such thing as global partitioner at all. There is only a default partitioner but it still has to be accessed through schema::get_partitioner.
There are some intermediate states in which i_partitioner is stored as shared_ptr in the schema but the final version keeps it by const&.
The PR does not enable per table partitioner end-to-end. Just the internals of the single node are covered. I still have to deal with:
- Making sure a table has the same partitioner on each node
- Allowing user to set up a table-specific partitioner on table
- Signal driver about what partitioner is used by a given table
- Persist partitioner info for each table that does not use default partitioner.
Fixes#5493
Tests: unit(dev, release, debug), dtest(byo)
"
* 'per_table_partitioner' of https://github.com/haaawk/scylla:
schema: drop optional from _partitioner field
make_multishard_combining_reader: stop taking partitioner
split_range_to_single_shard: stop taking partitioner as argument
tests: remove unused murmur3 includes
partitioner: move default_partitioner to schema.cc
partitioner: hide dht::default_partitioner
schema: include partitioner name in scylla tables mutation
schema: make it possible to set custom partitioner
scylla_tables: add partitioner column
schema_features: add PER_TABLE_PARTITIONERS feature
features: add PER_TABLE_PARTITIONERS feature
When the user performed
alter ks.t with compaction = {...}
the values of most other options, which were not specified in the
statement, e.g. compression, were left unchanged. That wasn't true for
extension options however: for example, the "cdc" option was removed.
This commit fixes the behavior to keep the old values of extension
options not specified in the alter statement.
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>
schema_builder::with_partitioner can be used now to
set custom partitioner on a table.
If no such partitioner is set, global partitioner is
still used.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
To increase modularity, making it easier to find what is where and
maintain.
The 'log' module (cdc/log.{hh,cc}) is responsible for updating CDC log
tables when base table writes are performed.
The 'generation' module (cdc/generation.{hh,cc}) handles stream
generation changes in response to topology change events.
cdc/metadata.{hh,cc} contains a helper class which holds the currently
used generation of streams. It is used by both aforementioned modules:
'log' queries it, while 'generation' updates it.
Some columns may represent not user-provided values, but ones computed
from other columns. Currently an example is token column used in secondary
indexes to provide proper ordering. In order to avoid hardcoding special
cases in execution stage, optional additional information for computed
columns is stored in column definition.
Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
Right now, schema_builder member functions have names that very poorly
convey the actions that are performed for them. This is made even worse
by some overloads which drastically change the semantics. For example:
schema_builder()
.with_column("v1", /* ... */)
.without_column("v1", removal_timestamp);
Creates a column "v1" and adds an information that there was a column
with that name that was removed at 'removal_timestamp'.
schema_builder()
.with_coulmn("v1")
.without_column(utf8_type->decompose("v1"));
This adds column "v1" and then immediately removes it.
In order to clean up this mess the names were changes so that:
* with_/without_ functions only add informations to the schema (e.g.
info that a column was removed, but without removing a column of that
name if one exists)
* functions which names start with a verb actually perform that action,
e.g. the new remove_column() removes the column (and adds information
that it used to exist) as in the second example.
In this patch we add a flag, "view virtual", that we can mark on on a
column defined in a schema. In following patches, we will add such virtual
columns to materialized views to allow view rows to remain alive despite
having no data (refs #3362).
After this patch, the "view virtual" flag exists in our in-memory
representation of the schema, but not persisted to disk - we will
fix this in the next patch.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
We are using C* 3.x compatible layout in schema tables but want to
keep using the 1.7 layout in memory for compatibility during rolling
upgrade. This patch switches the schema and schema_builder classes
back to the old layout. Translation of layout happens when converting
to/from schema mutations.
Notable changes:
1) Includes a revert of commit 6260f31e08
"thrift: Update CQL mapping of static CFs".
2) Brings back the "default_validation_class" schema attribute. In v3
it can be dervied from column definitions, but in v2 it can't, so
we have to store it.
3) legacy_schema_migrator and schema_builder don't have to do
conversions to v3, this is now handled by the v3_columns
class. schema_builder works with the same layout as schema, that
is v2.
4) Includes a revert of commit 66991a7ccb
"v3 schema test fixes"
Fixes#2555.
This patch adds a view_info optional field to the schema. It's
presence indicates the schema represents a materialized view.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
This patch ensures that when the schema is dense, regardless of
compact_storage being set, the single regular columns is translated
into a compact column.
This fixes an issue where Thrift dynamic column families are
translated to a dense schema with a regular column, instead of a
compact one.
Since a compact column is also a regular column (e.g., for purposes of
querying), no further changes are required.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <1470062410-1414-1-git-send-email-duarte@scylladb.com>
Cassandra disallows adding a column with the same name as a collection
that existed in the past in that table if the types aren't compatible.
To enforce that Scylla needs to keep track of all collections that ever
existed in the column family.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Knowing which columns were dropped (and when) is important to prevent
the data from the dropped ones reappearing if a new column is added with
the same name.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
The version needs to change value not only on structural changes but
also temporal. This is needed for nodes to detect if the version they
see was already synchronized with or not even if it has the same
structure as the past versions. We also need to end up with the same
version on all nodes when schema changes are commuted.
For regular mutable schemas version will be calculated from underlying
mutations when schema is announced. For static schemas of system
keyspace it is calculated by hashing scylla version and column id,
because we don't have mutations at the time of building the schema.
