The controller code sits in the cql_transport namespace and
can omit its mentionings. Also the seastar::distributed<>
is replaced with modern seastar::sharded<> while at it.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Now the controller has the lifecycle notifier reference and
can stop using storage service to manage the subscription.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
After subscription management was moved onto controller level
a bunch of code can be dropped:
- passing migration notifier beyond controller
- event_notifier's _stopped bit
- event_notifier .stop() method
- event_notifier empty constructor and destrictor
- generic_server's on_stop virtual method
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
There's a migration notifier that's carried through cql_server
_just_ to let event-notifier (un)subscribe on it. Also there's
a call for global storage-service in there which will need to
be replaced with yet another pass-through argument which is not
great.
It's easier to establish this subscription outside of cql_server
like it's currently done for proxy and sl-manager. In case of
cql_server the "outside" is the controller.
This patch just moves the subscription management from cql_server
to controller, next two patches will make more use of this change.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Both controller and server only need database to get config from.
Since controller creation only happens in main() code which has the
config itself, we may remove database mentioning from transport.
Previous attempt was not to carry the config down to the server
level, but it stepped on an updateable_value landmine -- the u._v.
isn't copyable cross-shard (despite the docs) and to properly
initialize server's max_concurrent_requests we need the config's
named_value member itself.
The db::config that flies through the stack is const reference, but
its named_values do not get copied along the way -- the updateable
value accepts both references and const references to subscribe on.
tests: start-stop in debug mode
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210607135656.18522-1-xemul@scylladb.com>
"
There's a bunch of issues with starting and stopping of cql_server with
the help of cql_controller.
fixes: #8796
tests: manual(start + stop,
start + exception on cql_set_state()
)
unit not run, they don't mess with transport controller
"
* 'br-transport-stop-fixes' of https://github.com/xemul/scylla:
transport/controller: Stop server on state change failure too
transport/controller: Rollback server start on state change failure too
transport/controller: Do not leave _server uninitialized
transport/controller: Rework try-catch into defers
If on stop the set_cql_state() throws the local sharded<cql_server>
will be left not stopped and will fail the respective assertion on
its destruction.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
If set_cql_state() throws the cserver remains started. If this
happens on start before the controller stop defer action is
scheduled the destruction of controller will fain on assertion
that checks the _server must be stopped.
Effectively this is the fix of #8796
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
If an exception happens after sharded<cql_server>.start() the
controller's _server pointer is left pointing to stopped sharded
server. This makes it impossible to start the server again (via
API) since the check for if (_server) will always be true.
This is the continuation of the ae4d5a60 fix.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The cql_server and alternator both need the limiter, so
patch them to stop using storage service's one and use
the main-local one.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Prepare memory limiters to have non-global instance of
the service. For now the main-local instance is not
used and (!) is not stopped for real, just like the
storage_service's one is.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The cql_server() need to get the memory limiter semaphore
from local storage service instance. To make this happen
a callback in introduced on the config structure. The same
can be achieved in a simler manner -- by providing the
local storage service instances directly.
Actually, the storage service will be removed in further
patches from this place, so this patch is mostly to get
rid of the callback from the config.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
On start the transport controller keeps the storage service
on server config's lambda just to let the server grab a
database config option.
The same can be achieved by passing the sharded database
reference to sharded<server>::start, so that each server
instance get local database with config.
As an nice side effect transport::server's config looks
more like a config with simple values and without methods
and/or lambdas on board.
tests: unit(dev)
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Message-Id: <20210205175611.13464-1-xemul@scylladb.com>
Fixes#7211
If we start a sharded<> object, then proceed to do potentially
exceptional stuff, we should destroy it on said exception.
Otherwise, the exception propagation will abort on RAII
destruction of the sharded<>. And we get no exception logging.
Recently, the cql_server_config::max_concurrent_requests field was
changed to be an updateable_value, so that it is updated when the
corresponding option in Scylla's configuration is live-reloaded.
Unfortunately, due to how cql_server is constructed, this caused
cql_server instances on all shards to store an updateable_value which
pointed to an updateable_value_source on shard 0. Unsynchronized
cross-shard memory operations ensue.
The fix changes the cql_server_config so that it holds a function which
creates an updateable_value appropriate for the given shard. This
pattern is similar to another, already existing option in the config:
get_service_memory_limiter_semaphore.
This fix can be reverted if updateable_value becomes safe to use across
shards.
Tests: unit(dev)
Fixes: #7310
This configuration entry is expected to be used as a quick fix
for an overloaded node, so it should be possible to reload this value
without having to restart the server.
The newly introduced parameter - max_concurrent_requests_per_shard
- can be used to limit the number of in-flight requests a single
coordinator shard can handle. Each surplus request will be
immediately refused by returning OverloadedException error to the client.
The default value for this parameter is large enough to never
actually shed any requests.
Currently, the limit is only applied to CQL requests - other frontends
like alternator and redis are not throttled yet.
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>
The new port is configurable from scylla.yaml and defaults to 19042
(unencrypted, unless client configures encryption options and omits
`native_shard_aware_transport_port_ssl`).
Two "SUPPORTED" tags are added: "SCYLLA_SHARD_AWARE_PORT" and
"SCYLLA_SHARD_AWARE_PORT_SSL". For compatibility,
"SCYLLA_SHARDING_ALGORITHM" is still kept.
Fixes#5239
Remove the on-storage_service instance and make everybody use
th standalone one.
Stopping the server is done by registering the controller in
client service shutdown hooks. This automatically wires the
stopping into drain, decommission and isolation codes.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
