Anonymous namespace implies internal linkage for its members.
When it is defined in a header, then each translation unit,
which includes such header defines its own unique instance
of members of the unnamed namespace that are ODR-used within
that translation unit.
This can lead to unexpected results including code bloat
or undefined behavior due to ODR violations.
This change aligns the code with the following guidelines:
- CppCoreGuidelines: "SF.21: Don’t use an unnamed (anonymous)
namespace in a header"
- SEI CERT C++: "DCL59-CPP. Do not define an unnamed namespace
in a header file"
Signed-off-by: Patryk Wrobel <patryk.wrobel@scylladb.com>
before this change, `std::invalid_argument` is thrown by
`bpo::notify(configuration)` in `app_template::run_deprecated()` when
invalid option is passed in via command line. `utils::named_value`
throws `std::invalid_argument` if the given value is not listed in
`_allowed_values`. but we don't handle `std::invalid_argument` in
`app_template::run_deprecated()`. so the application aborts with
unhandled exception if the specified argument is not allowed.
in this change, we convert the `std::invalid_argument` to a
derived class of `bpo::error` in the customized notify handler,
so that it can be handled in `app_template::run_deprecated()`.
because `name_value::operator()` is also used otherwhere, we
should not throw a bpo::error there. so its exception type
is preserved.
Fixes#16687
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
Closesscylladb/scylladb#16688
If `live_updatable_config_params_changeable_via_cql` is set to true, configuration parameters defined with `liveness::LiveUpdate` option can be updated in the runtime with CQL, i.e. by updating `system.config` virtual table.
If we don't want any configuration parameter to be changed in the
runtime by updating `system.config` virtual table, this option should be
set to false. This option should be set to false for e.g. cloud users,
who can only perform CQL queries, and should not be able to change
scylla's configuration on the fly.
Current implemenatation is generic, but has a small drawback - messages
returned to the user can be not fully accurate, consider:
```
cqlsh> UPDATE system.config SET value='2' WHERE name='task_ttl_in_seconds';
WriteFailure: Error from server: code=1500 [Replica(s) failed to execute write] message="option is not live-updateable" info={'failures': 1, 'received_responses': 0, 'required_responses': 1, 'consistency': 'ONE'}
```
where `task_ttl_in_seconds` has been defined with
`liveness::LiveUpdate`, but because `live_updatable_config_params_changeable_via_cql` is set to
`false` in `scylla.yaml,` `task_ttl_in_seconds` cannot be modified in the
runtime by updating `system.config` virtual table.
Fixes#14355Closes#14382
Currently when we set a single value we need
to call broadcast_to_all_shards to let observers on all
shards get notified of the new value.
However, the latter broadcasts all value to all shards
so it's terribly inefficient.
Instead, add async set_value_on_all_shards functions
to broadcast a value to all shards.
Use those in system_keyspace for db_config_table virtual table
and in task_manager_test to update the task_manager ttl.
Refs #7316
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
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
There soon will appear an updateable system.config table that
will push sstrings into names_value-s. Prepare for this change
by adding the respective .set_value() call. Since the update
only works for LiveUpdate-able options, and inability to do it
can be propagated back to the caller make this method return
true/false whether the update took place or not.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
config_file.cc instantiates std::istream& std::operator>>(std::istream&,
std::unordered_map<seastar::sstring, seastar::sstring>&), but that
instantiation is ignored since config_file_impl.hh specializes
that signature. -Winstantiation-after-specialization warns about it,
so re-enable it now that the code base is clean.
Also remove the matching "extern template" declaration, which has no
definition any more.
Closes#8696
Now that there are no ad-hoc aliases needing to overwrite the name and
description parameter of this method, we can drop these and have each
config item just use `name()` and `desc()` to access these.
Allow configuration items to also have an alias, besides the name.
This allows easy replacement of configuration items, with newer names,
while still supporting the old name for backward compatibility.
The alias mechanism takes care of registering both the name and the
alias as command line arguments, as well as parsing them from YAML.
The command line documentation of the alias will just refer to the name
for documentation.
Replace the per-shard value we store with an updateable_value_source, which
allows updating it dynamically and allows users to track changes.
The broadcast_to_all_shards() function is augmented to apply modifications
when called on a live system.
Currently, we allow adjusting configuration via
cfg.whatever() = 5;
by returning a mutable reference from cfg.whatever(). Soon, however, this operation
will have side effects (updating all references to the config item, and triggering
notifiers). While this can be done with a proxy, it is too tricky.
Switch to an ordinary setter interface:
cfg.whatever.set(5);
Because boost::program_options no longer gets a reference to the value to be written
to, we have to move the update to a notifier, and the value_ex() function has to
be adjusted to infer whether it was called with a vector type after it is
called, not before.
Currently, the REST API does its own conversion of named_value into json.
This requires it to use the _make_config_values macro to perform iteration
of all config items, since it needs to preserve the concrete type of the item
while iterating, so it can select the correct json conversion.
Since we want to remove that macro, we need to provide a different way to
convert a config item to json. So this patch adds a value_as_json().
To hide json_return_value from the rest of the system, we extend config_type
with a conversion function to handle the details. This usually calls
the json_return_type constructor directly, but when it doesn't have default
translation, it interposes a conversion into a type that json recognizes.
I didn't bother maintaining the existing type names, since they're C++
names which don't make sense for the UI.
The value_status is only needed at run-time, and removing it from the
template parameter list reduces type proliferation (which leads to code
bloat) and simplifies the code.
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>
Handling all the boost::commandline + YAML stuff.
This patch only provides an external version of these functions,
it does not modify the db::config object. That is for a follow-up
patch.
