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
And instantly convert the validate_keyspace() as it's not called
from anywhere but the validate_column_family().
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Straightforward replacement. Internals of the has_column_family_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]
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".
sprint() is obsolete. Note some calls where to helper functions that
use sprint(), not to sprint() directly, so both the helpers and
the callers were modified.
The new expr::visit() is just a wrapper around std::visit(),
but has better constraints. A call to expr::visit() with a
visitor that misses an overload will produce an error message
that points at the missing type. This is done using the new
invocable_on_expression concept. Note it lists the expression
types one by one rather than using template magic, since
otherwise we won't get the nice messages.
Later, we will change the implementation when expression becomes
our own type rather than std::variant.
Call sites are updated.
The code for checking that an MV's select statement doesn't
have any bind markers uses the wrong method and always returns
`false` even when it should not.
`prepare_context::empty()` is a misleading name because
it doesn't check if the current instance is empty, but creates
an empty instance wrapped in a `lw_shared_ptr` instead.
Thus, the code in `create_view_statement::announce_migration()`
checks that the pointer is not empty, which is always false.
Use `get_variable_specifications().empty()` to check that the
specifications vector inside the `prepare_context`
instance is not empty.
Tests: unit(dev)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
"
`function_call` AST nodes are created for each function
with side effects in a CQL query, i.e. non-deterministic
functions (`uuid()`, `now()` and some others timeuuid-related).
These nodes are evaluated either when a query itself is executed
or query restrictions are computed (e.g. partition/clustering
key ranges for LWT requests).
We need to cache the calls since otherwise when handling a
`bounce_to_shard` request for an LWT query, we can possibly
enter an infinite bouncing loop (in case a function is used
to calculate partition key ranges for a query), since the
results can be different each time.
Furthermore, we don't support bouncing more than one time.
Returning `bounce_to_shard` message more than one time
will result in a crash.
Caching works only for LWT statements and only for the function
calls that affect partition key range computation for the query.
`variable_specifications` class is renamed to `prepare_context`
and generalized to record information about each `function_call`
AST node and modify them, as needed:
* Check whether a given function call is a part of partition key
statement restriction.
* Assign ids for caching if above is true and the call is a part
of an LWT statement.
There is no need to include any kind of statement identifier
in the cache key since `query_options` (which holds the cache)
is limited to a single statement, anyway.
Function calls are indexed by the order in which they appear
within a statement while parsing. There is no need to
include any kind of statement identifier to the cache key
since `query_options` (which holds the cache) is limited
to a single statement, anyway.
Note that `function_call::raw` AST nodes are not created
for selection clauses of a SELECT statement hence they
can only accept only one of the following things as parameters:
* Other function calls.
* Literal values.
* Parameter markers.
In other words, only parameters that can be immediately reduced
to a byte buffer are allowed and we don't need to handle
database inputs to non-pure functions separately since they
are not possible in this context. Anyhow, we don't even have
a single non-pure function that accepts arguments, so precautions
are not needed at the moment.
Add a test written in `cql-pytest` framework to verify
that both prepared and unprepared lwt statements handle
`bounce_to_shard` messages correctly in such scenario.
Fixes: #8604
Tests: unit(dev, debug)
NOTE: the patchset uses `query_options` as a container for
cached values. This doesn't look clean and `service::query_state`
seems to be a better place to store them. But it's not
forwarded to most of the CQL code and would mean that a huge number
of places would have to be amended.
The series presents a trade-off to avoid forwarding `query_state`
everywhere (but maybe it's the thing that needs to be done, nonetheless).
"
* 'lwt_bounce_to_shard_cached_fn_v6' of https://github.com/ManManson/scylla:
cql-pytest: add a test for non-pure CQL functions
cql3: cache function calls evaluation for non-deterministic functions
cql3: rename `variable_specifications` to `prepare_context`
Now that all selectable::raw subclasses have been converted to
cql3::selectable::with_expression::raw, the class structure is
just a wrapper around expressions. Peel it, converting the
virtual member functions to free functions, and replacing
object instances with expression or nested_expression as the
case allows.
Add a field_selection variant element to expression. Like function_call
and cast, the structure from which a field is selectewd cannot yet be
an expression, since not all seletable::raw:s are converted. This will
be done in a later pass. This is also why printing a field selection now
does not print the selected expression; this will also be corrected later.
Add a function_call variant element to hold function calls. Note
that because not all selectables are yet converted, function call
arguments are still of type selectable::raw. They will be converted
to expressions later. This is also why printing a function now
does not print its arguments; this will also be corrected later.
Create a new element in the expression variant, column_mutation_attribute,
signifying we're picking up an attribute of a column mutation (not a
column value!). We use an enum rather than a bool to choose between
writetime and ttl (the two mutation attributes) for increased
explicitness.
Although there can only be one type for the column we're operating
on (it must be an unresolved_identifer), we use a nested_expression.
This is because we'll later need to also support a column_value
as the column type after we prepare it. This is somewhat similar
to the address of operator in C, which syntactically takes any
expression but semantically operates only on lvalues.
Introduce unresolved_identifer as an unprepared counterpart to column_value.
column_identifier_raw no longer inherits from selectable::raw, but
methods for now to reduce churn.
Prepare to migrate selectable::raw sub-classes to expressions by
creating a bridge betweet the two types. with_expression::raw
is a selectable::raw and implements all its methods (right now,
trivially), and its contents is an expression. The methods are
implemented using the usual visitor pattern.
The class is repurposed to be more generic and also be able
to hold additional metadata related to function calls within
a CQL statement. Rename all methods appropriately.
Visitor functions in AST nodes (`collect_marker_specification`)
are also renamed to a more generic `fill_prepare_context`.
The name `prepare_context` designates that this metadata
structure is a byproduct of `stmt::raw::prepare()` call and
is needed only for "prepare" step of query execution.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@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>
Currently there are places that call
keyspace_element_name::get_keyspace() without checking that _ks_name is
engaged. Fix those places.
Message-Id: <20210216085545.54753-1-gleb@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>
First of all, select statement is extended with an 'attrs' field,
which keeps the per-query attributes. Currently, only TIMEOUT
parameter is legal to use, since TIMESTAMP and TTL bear no meaning
for reads.
Secondly, if TIMEOUT attribute is set, it will be used as the effective
timeout for a particular query.
It is called from cql3/statements' check_access methods and from thrift
handlers. The former have proxy argument from which they can get the
database. The latter already have the database itself on board.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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>
Before this patch, when db/view/view.hh was modified, 89 source files had to
be recompiled. After this patch, this number is down to 5.
Most of the irrelevant source files got view.hh by including database.hh,
which included view.hh just for the definition of statistics. So in this
patch we split the view statistics to a separate header file, view_stats.hh,
and database.hh only includes that. A few source files which included
only database.hh and also needed view.hh (for materialized-view related
functions) now need to include view.hh explicitly.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
Message-Id: <20200319121031.540-1-nyh@scylladb.com>
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.
* Pass raw::select_statement::parameters as lw_shared_ptr
* Some more const cleanups here and there
* lists,maps,sets::equals now accept const-ref to *_type_impl
instead of shared_ptr
* Remove unused `get_column_for_condition` from modification_statement.hh
* More methods now accept const-refs instead of shared_ptr
Every call site where a shared_ptr was required as an argument
has been inspected to be sure that no dangling references are
possible.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200220153204.279940-1-pa.solodovnikov@scylladb.com>
De-pointerize cql3 code APIs further: change some call sites
to pass `schema` as const-ref instead of `shared_ptr`.
Affected functions known to be expecting always non-null
pointer to schema and don't store or pass the pointer somewhere
else, assuming it's safe to give them just a reference.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200218142338.69824-1-pa.solodovnikov@scylladb.com>
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>
There's no local variable to get features from in the
create_view_statement constructor, but since the .validate
is always called after it, it looks safe to check for
needed feature in it (we have storage_proxy there).
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
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>
`parsed_statement::get_bound_variables` is assumed to always
return a nonnull pointer to `variable_specifications` instance.
In this case using a pointer is superfluous and can be safely
replaced by a plain reference.
Also add a default ctor and a utility method `set_bound_variables`
to the `variable_specifications` class to actually reset the
contents of the class instance.
Tests: unit(dev, debug)
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
Message-Id: <20200120195839.164296-1-pa.solodovnikov@scylladb.com>
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
