Fixes some typos as found by codespell run on the code.
In this commit, I was hoping to fix only comments, not user-visible alerts, output, etc.
Follow-up commits will take care of them.
Refs: https://github.com/scylladb/scylladb/issues/16255
Signed-off-by: Yaniv Kaul <yaniv.kaul@scylladb.com>
Currently the bit is set in .shutdown() method which is called early on
stop. After the patch the bit it set in the abort-source subscription
callback which is also called early on stop.
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
This commit introduces a new boolean flag, `shutdown`, to the
forward_service, along with a corresponding shutdown method. It also
adds checks throughout the forward_service to verify the value of the
shutdown flag before retrying or invoking functions that might use the
messaging service under the hood.
The flag is set before messaging service shutdown, by invoking
forward_service::shutdown in main. By checking the flag before each call
that potentially involves the messaging service, we can ensure that the
messaging service is still operational. If the flag is false, indicating
that the messaging service is still active, we can proceed with the
call. In the event that the messaging service is shutdown during the
call, appropriate exceptions should be thrown somewhere down in called
functions, avoiding potential hangs.
This fix should resolve the issue where forward_service retries could
block the shutdown.
Fixes#12604Closes#13922
There are some headers that include tracing/*.hh ones despite all they
need is forward-declared trace_state_ptr
Signed-off-by: Pavel Emelyanov <xemul@scylladb.com>
Closes#14155
Failed-to-forward sub-queries will be executed locally (on a
super-coordinator). This local execution is meant as a fallback for
forward_requests that could not be sent to its destined coordinator
(e.g. due gossiper not reacting fast enough). Local execution was chosen
as the safest one - it does not require sending data to another
coordinator.
Coordinators processed each vnode sequentially on shards when executing
a `forward_request` sent by super-coordinator. This commit changes this
behavior and parallelizes execution of `forward_request` across shards.
It does that by adding additional layer of dispatching to
`forward_service`. When a coordinator receives a `forward_request`, it
forwards it to each of its shards. Shards slice `forward_request`'s
partition ranges so that they will only query data that is owned by
them. Implementation of slicing partition ranges was based on @nyh's
`token_ranges_owned_by_this_shard` from `alternator/ttl.cc`.
The new service is responsible for:
* spreading forward_request execution across multiple nodes in cluster
* collecting forward_request execution results and merging them
`forward_service::dispatch` method takes forward_request as an
argument, and forwards its execution to group of other nodes (using rpc
verb added in previous commits). Each node (in the group chosen by
dispatch method) is provided with forward_request, which is no different
from the original argument except for changed partition ranges. They are
changed so that vnodes contained in them are owned by recipient node.
Executing forward_request is realized in `forward_service::execute`
method, that is registered to be called on FORWARD_REQUEST verb receipt.
Process of executing forward_request consists of mocking few
non-serializable object (such as `cql3::selection`) in order to create
`service:pager:query_pagers::pager` and `cql3::selection::result_set_builder`.
After pager and result_set_builder creation, execution process resembles
what might be seen in select_statement's execution path.
