In early versions of the series which proposed protocol servers, the
interface had two methods answering pretty much the same question of
whether the server is running or not:
* listen_addresses(): empty list -> server not running
* is_server_running()
To reduce redundancy and to avoid possible inconsistencies between the
two methods, `is_server_running()` was scrapped, but re-added by a
follow-up patch because `listen_addresses()` proved to be unreliable as
a source for whether the server is running or not.
This patch restores the previous state of having only
`listen_addresses()` with two additional changes:
* rephrase the comment on `listen_addresses()` to make it clear that
implementations must return empty list when the server is not running;
* those implementations that have a reliable source of whether the
server is running or not, use it to force-return an empty list when
the server is not running
Tests: dtest(nodetool_additional_test.py)
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20211117062539.16932-1-bdenes@scylladb.com>
Change b0a2a9771f broke
the generic api implementation of
is_native_transport_running that relied on
the addresses list being empty agter the server is stopped.
To fix that, this change introduces a pure virtual method:
protocol_server::is_server_running that can be implemented
by each derived class.
Test: unit(dev)
DTest: nodetool_additional_test.py:TestNodetool.binary_test
Signed-off-by: Benny Halevy <bhalevy@scylladb.com>
Message-Id: <20211114135248.588798-1-bhalevy@scylladb.com>
"
On start scylla resolves several hostnames into addresses. Different
places use different hostname selection logic, e.g. the API address
can be the listen one if the dedicated option not set. Failure to
resolve a hostname is reported with an exception that (sometimes)
contains the hostname, but it doesn't look very convenient -- better
to know the config option name. Also resolving of different hostnames
has different decoration around, e.g. prometheus carries a main-local
lambda just to nicely wrap the try/catch block.
This set unifies this zoo and makes main() shorter and less hairy:
1. All failures to resolve a hostname are reported with an
exception containing the relevant config option
2. The || operator for named_value's is introduced to make
the option selection look as short as
resolve(cfg->some_address() || cfg->another_address())
3. All sanity checks are explicit and happen early in main
4. No dangling local variables carrying the cfg->...() value
5. Use resolved IP when logging a "... is listening on ..."
message after a service start
tests: unit(dev)
"
* 'br-ip-resolve-on-start' of https://github.com/xemul/scylla:
main: Move fb-utilities initialization up the main
code: Use utils::resolve instead of inet_address::lookup
main: Remove unused variable
main: Sanitize resolving of listen address
main: Sanitize resolving of broadcast address
main: Sanitize resolving of broadcast RPC address
main: Sanitize resolving of API address
main: Sanitize resolving of prometheus address
utils: Introduce || operator for named_values
db.config: Verbose address resolver helper
main: Remove api-port and prometheus-port variables
alternator: Resolve address with the help of inet_address
redis, thrift: Remove unused captures
There are some users of the latter call left. They all suffer
from the same problem -- the lack of verbosity on resolving
errors.
While at it also get rid of useless local variables that are
only there to carry the cfg->...() option over.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
The thrift_handler class' methods need storage service. This
patch makes sure this class has sharded storage service
reference on board.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Some .cc files over the code include the storage service
for no real need. Drop the header and include (in some)
what's really needed.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This commit adds admission control in the form of passing
service permits to the Thrift server.
The support is partial, because Thrift also supports running CQL
queries, and for that purpose a query_state object is kept
in the Thrift handler. However, the handler is generally created
once per connection, not once per query, and the query_state object
is supposed to keep the state of a single query only.
In order to keep this series simpler, the CQL-on-top-of-Thrift
layer is not touched and is left as TODO.
Moreover, the Thrift layer does not make it easy to pass custom
per-query context (like service_permit), so the implementation
uses a trick: the service permit is created on the server
and then passed as reference to its connections and their respective
Thrift handlers. Then, each time a query is read from the socket,
this service permit is overwritten and then read back from the Thrift
handler. This mechanism heavily relies on the fact that there are
zero preemption points between overwriting the service permit
and reading it back by the handler. Otherwise, races may occur.
This assumption was verified by code inspection + empirical tests,
but if somebody is aware that it may not always hold, please speak up.
Remove the on-storage_service instance and make everybody use
th standalone one.
Stopping the thrift 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>
