Tablets load balancer is unable to process more than a single pending
replica, thus ALTER tablets KS cannot accept an ALTER statement which
would result in creating 2+ pending replicas, hence it has to validate
if the sum of absoulte differences of RFs specified in the statement is
not greter than 1.
(cherry picked from commit ee56bbfe61)
A bug has been discovered while trying to ALTER tablets KS and
specifying only 1 out of 2 DCs - the not specified DC's RF has been
zeroed. This is because ALTER tablets KS updated the KS only with the
RF-per-DC mapping specified in the ALTER tablets KS statement, so if a
DC was ommitted, it was assigned a value of RF=0.
This commit fixes that plus additionally passes all the KS options, not
only the replication options, to the topology coordinator, where the KS
update is performed.
`initial_tablets` is a special case, which requires a special handling
in the source code, as we cannot simply update old initial_tablet's
settings with the new ones, because if only ` and TABLETS = {'enabled':
true}` is specified in the ALTER tablets KS statement, we should not zero the `initial_tablets`, but
rather keep the old value - this is tested by the
`test_alter_preserves_tablets_if_initial_tablets_skipped` testcase.
Other than that, the above mentioned testcase started to fail with
these changes, and it appeared to be an issue with the test not waiting
until ALTER is completed, and thus reading the old value, hence the
test's body has been modified to wait for ALTER to complete before
performing validation.
(cherry picked from commit 2aabe7f09c)
The validation has been corrected with:
1. Checking if a DC specified in ALTER exists.
2. Removing `REPLICATION_STRATEGY_CLASS_KEY` key from a map of RFs that
needs their RFs to be validated.
(cherry picked from commit 6676e47371)
This function assumed that strings passed as arguments will be of
integer types, but that wasn't the case, and we missed that because this
function didn't have any validation, so this change adds proper
validation and error logging.
Arguments passed to this function were forwarded from a call to
`ks_prop_defs::get_replication_options`, which, among rf-per-dc mapping, returns also
`class:replication_strategy` pair. Second pair's member has been casted
into an `int` type and somehow the code was still running fine, but only
extra testing added later discovered a bug in here.
(cherry picked from commit 93d61d7031)
ALTER tablets KS validated if RF is not changed by more than 1 for DCs
that already had replicas, but not for DCs that didn't have them yet, so
specifying an RF jump from 0 to 2 was possible when listing a new DC in
ALTER tablets KS statement, which violated internal invariants of
tablets load balancer.
This PR fixes that bug and adds a multi-dc testcases to check if adding
replicas to a new DC and removing replicas from a DC is honoring the RF
change constraints.
Refs: #20039
(cherry picked from commit 47acdc1f98)
before this change, we rely on `using namespace seastar` to use
`seastar::format()` without qualifying the `format()` with its
namespace. this works fine until we changed the parameter type
of format string `seastar::format()` from `const char*` to
`fmt::format_string<...>`. this change practically invited
`seastar::format()` to the club of `std::format()` and `fmt::format()`,
where all members accept a templated parameter as its `fmt`
parameter. and `seastar::format()` is not the best candidate anymore.
despite that argument-dependent lookup (ADT for short) favors the
function which is in the same namespace as its parameter, but
`using namespace` makes `seastar::format()` more competitive,
so both `std::format()` and `seastar::format()` are considered
as the condidates.
that is what is happening scylladb in quite a few caller sites of
`format()`, hence ADT is not able to tell which function the winner
in the name lookup:
```
/__w/scylladb/scylladb/mutation/mutation_fragment_stream_validator.cc:265:12: error: call to 'format' is ambiguous
265 | return format("{} ({}.{} {})", _name_view, s.ks_name(), s.cf_name(), s.id());
| ^~~~~~
/usr/bin/../lib/gcc/x86_64-redhat-linux/14/../../../../include/c++/14/format:4290:5: note: candidate function [with _Args = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
4290 | format(format_string<_Args...> __fmt, _Args&&... __args)
| ^
/__w/scylladb/scylladb/seastar/include/seastar/core/print.hh:143:1: note: candidate function [with A = <const std::basic_string_view<char> &, const seastar::basic_sstring<char, unsigned int, 15> &, const seastar::basic_sstring<char, unsigned int, 15> &, const utils::tagged_uuid<table_id_tag> &>]
143 | format(fmt::format_string<A...> fmt, A&&... a) {
| ^
```
in this change, we
change all `format()` to either `fmt::format()` or `seastar::format()`
with following rules:
- if the caller expects an `sstring` or `std::string_view`, change to
`seastar::format()`
- if the caller expects an `std::string`, change to `fmt::format()`.
because, `sstring::operator std::basic_string` would incur a deep
copy.
we will need another change to enable scylladb to compile with the
latest seastar. namely, to pass the format string as a templated
parameter down to helper functions which format their parameters.
to miminize the scope of this change, let's include that change when
bumping up the seastar submodule. as that change will depend on
the seastar change.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Now when function context creation is encapsulated in lang::manager,
some .cc files can stop using wasm-specific headers and just go with the
lang/manager.hh one.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This is done to achieve single transaction semantics.
The change includes auto-grant feature. In particular
for schema related auto-grant we don't use normal
mutation collector announce path but follow migration manager,
this may be unified in the future.
We want to ensure that when the replication factor
of a keyspace changes, it changes by at most 1 per DC
if it uses tablets. The rationale for that is to make
sure that the old and new quorums overlap by at least
one node.
After these changes, attempts to change the RF of
a keyspace in any DC by more than 1 will fail.
This patch removes the support for the "wildcard" replication_factor
option for ALTER KEYSPACE when the keyspace supports tablets.
It will still be supported for CREATE KEYSPACE so that a user doesn't
have to know all datacenter names when creating the keyspace,
but ALTER KEYSPACE will require that and the user will have to
specify the exact change in replication factors they wish to make by
explicitly specifying the datacenter names.
Expanding the replication_factor option in the ALTER case is
unintuitive and it's a trap many users fell into.
See #8881, #15391, #16115
This commit adds support for executing ALTER KS for keyspaces with
tablets and utilizes all the previous commits.
The ALTER KS is handled in alter_keyspace_statement, where a global
topology request in generated with data attached to system.topology
table. Then, once topology state machine is ready, it starts to handle
this global topology event, which results in producing mutations
required to change the schema of the keyspace, delete the
system.topology's global req, produce tablets mutations and additional
mutations for a table tracking the lifetime of the whole req. Tracking
the lifetime is necessary to not return the control to the user too
early, so the query processor only returns the response while the
mutations are sent.
This kills three birds with one stone
1. fixes broken indentation
2. re-uses new_options local variable
3. stops using string literal to check storage type
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closesscylladb/scylladb#17111
Previous patch added params to r.s. classes' constructors, but callers
don't construct those directly, instead they use the create_r.s.()
wrapper. This patch adds params to the wrapper too.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
When ALTER-ing a keyspace one may as well change its vnode/tablet
flavor, which is not currently supported, so prohibit this change
explicitly
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Replacing `restrict_replication_simplestrategy` config option with
2 config options: `replication_strategy_{warn,fail}_list`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on replication strategy when creating/altering a keyspace.
The reason to rather replace than extend `restrict_replication_simplestrategy` config
option is that it was not used and we wanted to generalize it.
Only soft guardrail is enabled by default and it is set to SimpleStrategy,
which means that we'll generate a CQL warning whenever replication strategy
is set to SimpleStrategy. For new cloud deployments we'll move
SimpleStrategy from warn to the fail list.
Guardrails violations will be tracked by metrics.
Resolves#5224
Refs #8892 (the replication strategy part, not the RF part)
Closesscylladb/scylladb#15399
Replacing `minimum_keyspace_rf` config option with 4 config options:
`{minimum,maximum}_replication_factor_{warn,fail}_threshold`, which
allow us to impose soft limits (issue a warning) and hard limits (not
execute CQL) on RF when creating/altering a keyspace.
The reason to rather replace than extend `minimum_keyspace_rf` config
option is to be aligned with Cassandra, which did the same, and has the
same parameters' names.
Only min soft limit is enabled by default and it is set to 3, which means
that we'll generate a CQL warning whenever RF is set to either 1 or 2.
RF's value of 0 is always allowed and means that there will not be any
replicas on a given DC. This was agreed with PM.
Because we don't allow to change guardrails' values when scylla is
running (per PM), there're no tests provided with this PR, and dtests will be
provided separately.
Exceeding guardrails' thresholds will be tracked by metrics.
Resolves#8619
Refs #8892 (the RF part, not the replication-strategy part)
Closes#14262
Currently we hold group0_guard only during DDL statement's execute()
function, but unfortunately some statements access underlying schema
state also during check_access() and validate() calls which are called
by the query_processor before it calls execute. We need to cover those
calls with group0_guard as well and also move retry loop up. This patch
does it by introducing new function to cql_statement class take_guard().
Schema altering statements return group0 guard while others do not
return any guard. Query processor takes this guard at the beginning of a
statement execution and retries if service::group0_concurrent_modification
is thrown. The guard is passed to the execute in query_state structure.
Fixes: #13942
Message-ID: <ZNsynXayKim2XAFr@scylladb.com>
This reverts commit 70b5360a73. It generates
a failure in group0_test .test_concurrent_group0_modifications in debug
mode with about 4% probability.
Fixes#15050
Currently we hold group0_guard only during DDL statement's execute()
function, but unfortunately some statements access underlying schema
state also during check_access() and validate() calls which are called
by the query_processor before it calls execute. We need to cover those
calls with group0_guard as well and also move retry loop up. This patch
does it by introducing new function to cql_statement class take_guard().
Schema altering statements return group0 guard while others do not
return any guard. Query processor takes this guard at the beginning of a
statement execution and retries if service::group0_concurrent_modification
is thrown. The guard is passed to the execute in query_state structure.
Fixes: #13942
Message-ID: <ZNSWF/cHuvcd+g1t@scylladb.com>
After changing the prepare_ methods of migration_manager to
functions, the migration_manager& parameter of
schema_altering_statement::prepare_schema_mutations has been
unused by all classes inheriting from schema_altering_statement.
The migration_manager service is responsible for schema convergence
in the cluster - pushing schema changes to other nodes and pulling
schema when a version mismatch is observed. However, there is also
a part of migration_manager that doesn't really belong there -
creating mutations for schema updates. These are the functions with
prepare_ prefix. They don't modify any state and don't exchange any
messages. They only need to read the local database.
We take these functions out of migration_manager and make them
separate functions to reduce the dependency of other modules
(especially query_processor and CQL statements) on
migration_manager. Since all of these functions only need access
to storage_proxy (or even only replica::database), doing such a
refactor is not complicated. We just have to add one parameter,
either storage_proxy or database and both of them are easily
accessible in the places where these functions are called.
We want to stop relying on `qp.get_migration_manager()`, so we can make
the function private in the future. This in turn is a prerequisite for
splitting `query_processor` initialization into two phases, where the
first phase will only allow local queries (and won't require
`migration_manager`).
Validation of a CREATE MATERIALIZED VIEW statement takes place inside
the prepare_schema_mutations() method.
I would like to generate warnings during this validation, but there's
currently no way to pass them.
Let's add one more return value - a vector of CQL warnings generated
during the execution of this statement.
A new alias is added to make it clear what the function is returning:
```c++
// A vector of CQL warnings generated during execution of a statement.
using cql_warnings_vec = std::vector<sstring>;
```
Later the warnings will be sent to the user by the function
schema_altering_statment::execute(), which is the only caller
of prepare_schema_mutations().
Signed-off-by: Jan Ciolek <jan.ciolek@scylladb.com>
these warnings are found by Clang-17 after removing
`-Wno-unused-lambda-capture` and '-Wno-unused-variable' from
the list of disabled warnings in `configure.py`.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
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
Each feature has a private variable and a public accessor. Since the
accessor effectively makes the variable public, avoid the intermediary
and make the variable public directly.
To ease mechanical translation, the variable name is chosen as
the function name (without the cluster_supports_ prefix).
References throughout the codebase are adjusted.
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
```
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>
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".
In the previous patch we made CREATE KEYSPACE honor the
"restrict_replication_simplestrategy" option. In this patch we do the
same for ALTER KEYSPACE.
We use the same function check_restricted_replication_strategy()
used in CREATE KEYSPACE for the logic of what to allow depending on the
configuration, and what errors or warnings to generate.
One of the non-self-explanatory changes in this patch is to execute():
Previosuly, alter_keyspace_statement inherited its execute() from
schema_altering_statement. Now we need to override it to check if the
operation is forbidden before running schema_altering_statement's execute()
or to warn after it is run. In the previous patch we didn't need to add
a new execute() for create_keyspace_statement because we already had one.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
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.
Most of the schema altering statements implementations can now
stop calling for global migration manager instance and get it
from the query processor.
Here are the trivial cases when the query processor is just
avaiable at the place where it's needed.
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>
