It is unsafe to do `get_server_with_timeouts().read_barrier()` in
continuations because `get_server_with_timeouts()` returns
raft server by value and it may be deallocated when `read_barrier()` yields,
causing use-after-return.
Simple workaround is to use the read barrier in coroutine and co_await
it. Then the raft server is kept on stack until the read barrier is
finished.
I've checked all codebase and it looks like the only place where
`group0_with_timeouts().read_barrier()` is in continuation, is
api/raft.cc.
Co-authored-by: Piotr Dulikowski <piodul@scylladb.com>
the log.hh under the root of the tree was created keep the backward
compatibility when seastar was extracted into a separate library.
so log.hh should belong to `utils` directory, as it is based solely
on seastar, and can be used all subsystems.
in this change, we move log.hh into utils/log.hh to that it is more
modularized. and this also improves the readability, when one see
`#include "utils/log.hh"`, it is obvious that this source file
needs the logging system, instead of its own log facility -- please
note, we do have two other `log.hh` in the tree.
Signed-off-by: Kefu Chai <kefu.chai@scylladb.com>
The leader_host API handler was eventually using the `req` unique_ptr
after it has been already destroyed (passed down to the future lambda
by reference). This was causing an occassional crash in some tests.
Reworked the leader_host handler to use the req only outside of the
future lambda.
Also updated the code to handle the possibility that the non-default
leader group (other than Group 0) might reside on a different shard
than the shard 0 - using the same concept of calling on all shards via
`invoke_on_all()` as done for the other requests.
Fixesscylladb/scylladb#19714Closesscylladb/scylladb#19715
This will allow to trigger the read barrier directly via the API,
instead of doing work-arounds (like dropping a non-existent table).
The intended use-case is in the Scylla Manager, to make sure that
the database schema is up to date after the data has been backed up
and before attempting to backup the database schema.
The database schema in particular is being backed up just on a single
node, which might not yet have the schema at least as new as the data
(data can be migrated to a newer schema, but not a vice-versa).
The read barrier issued on the node should ensure that the node should
have the schema at least as new as the data or newer.
Closes#19213
The API req->param["name"] to access parameters in the path part of the
URL was buggy - it forgot to do URL decoding and the result of our use
of it in Scylla was bugs like #5883 - where special characters in certain
REST API requests got botched up (encoded by the client, then not
decoded by the server).
The solution is to replace all uses of req->param["name"] by the new
req->get_path_param("name"), which does the decoding correctly.
Unfortunately we needed to change 104 (!) callers in this patch, but the
transformation is mostly mechanical and there is no functional changes in
this patch. Another set of changes was to bring req, not req->param, to
a few functions that want to get the path param.
This patch avoids the numerous deprecation warnings we had before, and
more importantly, it fixes#5883.
Signed-off-by: Nadav Har'El <nyh@scylladb.com>
This uses the `trigger_snapshot()` API added in previous commit on a
server running for the given Raft group.
It can be used for example in tests or in the context of disaster
recovery (ref scylladb/scylladb#16683).
