The functions which prepare schema change mutations (such as
`prepare_new_column_family_announcement`) would use internally
generated timestamps for these mutations. When schema changes are
managed by group 0 we want to ensure that timestamps of mutations
applied through Raft are monotonic. We will generate these timestamps at
call sites and pass them into the `prepare_` functions. This commit
prepares the APIs.
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
Straightforward replacement. Internals of the has_keyspace_access()
temporarily get .real_database(), but it will be changed soon.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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]
After previous patches there's a whole bunch of places that do
qp.proxy().data_dictionary()
while the data_dictionary is present on the query processor itself
and there's a public method to get one. So use it everywhere.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This is mostly a sed script that replaces methods' first argument
plus fixes of compiler-generated errors.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Stop using database (and including database.hh) for schema related
purposes and use data_dictionary instead.
data_dictionary::database::real_database() is called from several
places, for these reasons:
- calling yet-to-be-converted code
- callers with a legitimate need to access data (e.g. system_keyspace)
but with the ::database accessor removed from query_processor.
We'll need to find another way to supply system_keyspace with
data access.
- to gain access to the wasm engine for testing whether used
defined functions compile. We'll have to find another way to
do this as well.
The change is a straightforward replacement. One case in
modification_statement had to change a capture, but everything else
was just a search-and-replace.
Some files that lost "database.hh" gained "mutation.hh", which they
previously had access to through "database.hh".
DateTieredCompactionStrategy (DTCS) has been un-recommended for a long time
(users should use TimeWindowCompactionStrategy, TWCS, instead). This
patch adds a new configuration option - restrict_dtcs - which can be used
to restrict the ability to use DTCS in CREATE TABLE or ALTER TABLE
statements. This is part of a "safe mode" effort to allow an installation
to restrict operations which are un-recommended or dangerous.
The new restrict_dtcs option has three values: "true", "false", and "warn":
For the time being, "false" is still the default, and means DTCS is not
restricted and can still be used freely. We can easily change this
default in a followup patch.
Setting a value of "true" means that DTCS *is* restricted -
trying to create a a table or alter a table with it will fail with an error.
Setting a value of "warn" will allow the create or alter operation, but
will warn the user - both with a warning message which will immediately
appear in cqlsh (for example), and with a log message.
Fixes#8914.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20210624122411.435361-1-nyh@scylladb.com>
After previous patches some places in cql3 code take a
long path to get database reference:
query processor -> storage proxy -> database
The query processor can provide the database reference
by itself, so take this chance.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
There are few schema altering statements that need to have
the query processor inside lambda continuations. Fortunately,
they all are continuations of make_ready_future<>()s, so the
query processor can be simply captured by reference and used.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Now when the only call to .announce_migration gas the
query processor at hands -- pass it to the real statements.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
It looks like the history of the flag begins in Cassandra's
https://issues.apache.org/jira/browse/CASSANDRA-7327 where it is
introduced to speedup tests by not needing to start the gossiper.
The thing is we always start gossiper in our cql tests, so the flag only
introduce noise. And, of course, since we want to move schema to use raft
it goes against the nature of the raft to be able to apply modification only
locally, so we better get rid of the capability ASAP.
Tests: units(dev, debug)
Message-Id: <20201230111101.4037543-2-gleb@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>
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)
If sstring is made an alias to std::string ADL causes std::make_shared
to be found. Explicitly ask for ::make_shared.
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
Moves initialization of schema extensions outside of cf_prop_defs. This
allows to construct these extensions once, and use them several times in
cd_prop_defs' methods without caching or recalculating them several
times.
Changes cf_prop_defs::validate function to take database& as an argument
instead of db::extensions&. This change will allow us to move the check
which asserts that the cluster supports CDC from `apply_to_builder` to
`validate` method.
Convert some more helper functions to accept const reference to
column_specification and column_identifier instead of shared_ptr.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
cql3 has cql_statement, parsed_statement and prepared_statement
classes, which, largely, stand for the same thing. prepared was
an alias for prepared_statement which only required an extra
tag jump in IDE and carried no meaning.
Keep local feature_service reference on database. This relaxes the
circular storage_service <-> database reference, but not removes it
completely.
This needs some args tossing in apply_to_builder, but it's
rather straightforward, so comes in the same patch.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This allows us to create/alter/drop log and desc tables "atomically"
with the base, by including these mutations in the original mutation
set, i.e. batch create/alter tables.
Note that population does not happen until types are actually
already put into database (duh), thus there _is_ still a gap
between creating cdc and it being truly usable. This may or may
not need handling later.
cql_statement is a class representing a prepared statement in Scylla.
It is used concurrently during execution, so it is important that its
change is not changed by execution.
Add const qualifier to the execution methods family, throghout the
cql hierarchy.
Mark a few places which do mutate prepared statement state during
execution as mutable. While these are not affecting production today,
as code ages, they may become a source of latent bugs and should be
moved out of the prepared state or evaluated at prepare eventually:
cf_property_defs::_compaction_strategy_class
list_permissions_statement::_resource
permission_altering_statement::_resource
property_definitions::_properties
select_statement::_opts
Add a cluster feature for non-frozen UDTs.
If the cluster supports non-frozen UDTs, do not return an error
message when trying to create a table with a non-frozen user type.
This patch wrapps announce_migration logic into a lambda
that will be used both when cdc is used and when it's not.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Both cql3_type and abstract_type are normally used inside
shared_ptr. This creates a problem when an abstract_type needs to refer
to a cql3_type as that creates a cycle.
To avoid warnings from asan, we were using a std::unordered_map to
store one of the edges of the cycle. This avoids the warning, but
wastes even more memory.
Even before this patch cql3_type was a fairly light weight
structure. This patch pushes in that direction and now cql3_type is a
struct with a single member variable, a data_type.
This avoids the reference cycle and is easier to understand IMHO.
Tests: unit (dev)
Signed-off-by: Rafael Ávila de Espíndola <espindola@scylladb.com>
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>
This header, which is easily replaced with a forward declaration,
introduces a dependency on database.hh everywhere. Remove it and scatter
includes of database.hh in source files that really need it.
Instead, distribute those inclusions to .cc files that require them. This
reduces rebuilds when config.hh changes, and makes it easier to locate files
that need config disaggregation.
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
The storage_proxy represents the entire cluster, so there's never a need
to access it on a remote shard; the local shard instance will contact
remote shard or remote nodes as needed.
Simplify the API by passing storage_proxy references instead of
seastar::sharded<storage_proxy> references. query_processor and
other callers are adjusted to call seastar::sharded::local() first.
Message-Id: <20180415142656.25370-2-avi@scylladb.com>
When a table, keyspace, or role is created, the creator now is
automatically granted all applicable permissions on the object.
This behavior is consistent with Apache Cassandra.
Fixes#3216.
Automatically accept registered schema extensions into the properties
set, and when building, generate the corresponding extension object into
the resulting schema.
`duration` is a new native type that was introduced in Cassandra 3.10 [1].
Support for parsing and the internal representation of the type was added in
8fa47b74e8.
Important note: The version of cqlsh distributed with Scylla does not have
support for durations included (it was added to Cassandra in [2]). To test this
change, you can use cqlsh distributed with Cassandra.
Duration types are useful when working with time-series tables, because they can
be used to manipulate date-time values in relative terms.
Two interesting applications are:
- Aggregation by time intervals [3]:
`SELECT * FROM my_table GROUP BY floor(time, 3h)`
- Querying on changes in date-times:
`SELECT ... WHERE last_heartbeat_time < now() - 3h`
(Note: neither of these is currently supported, though columns with duration
values are.)
Internally, durations are represented as three signed counters: one for months,
for days, and for nanoseconds. Each of these counters is serialized using a
variable-length encoding which is described in version 5 of the CQL native
protocol specification.
The representation of a duration as three counters means that a semantic
ordering on durations doesn't exist: Is `1mo` greater than `1mo1d`? We cannot
know, because some months have more days than others. Durations can only have a
concrete absolute value when they are "attached" to absolute date-time
references. For example, `2015-04-31 at 12:00:00 + 1mo`.
That duration values are not comparable presents some difficulties for the
implementation, because most CQL types are. Like in Cassandra's implementation
[2], I adopted a similar strategy to the way restrictions on the `counter` type
are checked. A type "references" a duration if it is either a duration or it
contains a duration (like a `tuple<..., duration, ...>`, or a UDT with a
duration member).
The following restrictions apply on durations. Note that some of these contexts
are either experimental features (materialized views), or not currently
supported at run-time (though support exists in the parser and code, so it is
prudent to add the restrictions now):
- Durations cannot appear in any part of a primary key, either for tables or
materialized views.
- Durations cannot be directly used as the element type of a `set`, nor can they
be used as the key type of a `map`. Because internal ordering on durations is
based on a byte-level comparison, this property of Cassandra was intended to
help avoid user confusion around ordering of collection elements.
- Secondary indexes on durations are not supported.
- "Slice" relations (<=, <, >=, >) are not supported on durations with `WHERE`
restrictions (like `SELECT ... WHERE span <= 3d`). Multi-column restrictions
only work with clustering columns, which cannot be `duration` due to the
first rule.
- "Slice" relations are not supported on durations with query conditions (like
`UPDATE my_table ... IF span > 5us`).
Backwards incompatibility note:
As described in the documentation [4], duration literals take one of two
forms: either ISO 8601 formats (there are three), or a "standard" format. The ISO
8601 formats start with "P" (like "P5W"). Therefore, identifiers that have this
form are no longer supported.
Fixes#2240.
[1] https://issues.apache.org/jira/browse/CASSANDRA-11873
[2] bfd57d13b7
[3] https://issues.apache.org/jira/browse/CASSANDRA-11871
[4] http://cassandra.apache.org/doc/latest/cql/types.html#working-with-durations
