these unused includes are identified by clang-include-cleaner.
after auditing the source files, all of the reports have been
confirmed.
please note, since we have `using seastar::shared_ptr` in
`seastarx.h`, this renders `#include <seastar/core/shared_ptr.hh>`
unnecessary if we don't need the full definition of `seastar::shared_ptr`.
so, in this change, all the unused includes are removed. but there are
some headers which are actually used, while still being identified by
this tool. these includes are marked with "IWYU pragma: keep".
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
In this patch we add 2 tests for checking that the mv admission control works.
The first one simply checks whether, after increasing the backlog on one node
over the admission control threshold, the following request is rejected with
the error message corresponding to the admission control.
The second one checks whether, after triggering admission control, the entire
user request fails instead of just failing a replica write. This is done by
performing a number of writes, some of which trigger the admission control
and cause retries, then checking if the node that had a large view update backlog
received all the writes. Before, the writes would succeed on enough replicas,
reaching QUORUM, and allowing the user write to succeed and cause no retries,
even though on the replica with a high backlog the write got rejected due to
the backlog size.
Currently, there are 2 ways of sharing a backlog with other nodes: through
a gossip mechanism, and with responses to replica writes. In gossip, we
check each second if the backlog changed, and if it did we update other
nodes with it. However if the backlog for this node changed on another
node with a write response, the gossiped backlog is currently not updated,
so if after the response the backlog goes back to the value from the previous
gossip round, it will not get sent and the other node will stay with an
outdated backlog.
This patch changes this by notifying the gossip that a the backlog changed
since the last gossip round so a different backlog could have been send
through the response piggyback mechanism. With that information, gossip
will send an unchanged backlog to other nodes in the following gossip round.
Fixes: https://github.com/scylladb/scylladb/issues/18461
Currently, we only update the backlogs in node_update_backlog at the
same time when we're fetching them. This is done using storage_proxy's
method get_view_update_backlog, which is confusing because it's a getter
with side-effects. Additionally, we don't always want to update the
backlog when we're reading it (as in gossip which is only on shard 0)
and we don't always want to read it when we're updating it (when we're
not handling any writes but the backlog drops due to background work
finish).
This patch divides the node_view_backlog::add_fetch as well the
storage_proxy::get_view_update_backlog both into two methods; one
for updating and one for reading the backlog. This patch only replaces
the places where we're currently using the view backlog getter, more
situations where we should get/update the backlog should be considered
in a following patch.
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
