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
This warning prevents using std::move() where it can hurt
- on an unnamed temporary or a named automatic variable being
returned from a function. In both cases the value could be
constructed directly in its final destination, but std::move()
prevents it.
Fix the handful of cases (all trivial), and enable the warning.
Closes#8992
Test that if leadership transfer cannot be done in configured time frame
fsm cancels the leadership transfer process. Also check that timeout_now
message is resent on each tick while leadership transfer is in progress.
Use vector instead of initializer_list for function helper parameter.
This is not a constructor and it complicates usage.
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
It is generally considered a bad practice to use the `using`
directives at global scope in header files.
Also, many parts of `test/raft/helpers.hh` were already
using `raft::` prefixes explicitly, so definitely not much
to lose there.
Signed-off-by: Pavel Solodovnikov <pa.solodovnikov@scylladb.com>
When probes are sent over a slow network, the leader would send
multiple probes to a lagging follower before it would get a
reject response to the first probe back. After getting a reject, the
leader will be able to correctly position `next_idx` for that
follower and switch to pipeline mode. Then, an out of order reject
to a now irrelevant probe could crash the leader, since it would
effectively request it to "rewind" its `match_idx` for that
follower, and the code asserts this never happens.
We fix the problem by strengthening `is_stray_reject`. The check that
was previously only made in `PIPELINE` case
(`rejected.non_matching_idx <= match_idx`) is now always performed and
we add a new check: `rejected.last_idx < match_idx`. We also strengthen
the assert.
The commit improves the documentation by explaining that
`is_stray_reject` may return false negatives. We also precisely state
the preconditions and postconditions of `is_stray_reject`, give a more
precise definition of `progress.match_idx`, argue how the
postconditions of `is_stray_reject` follow from its preconditions
and Raft invariants, and argue why the (strengthened) assert
must always pass.
Message-Id: <20210423173117.32939-1-kbraun@scylladb.com>
Two helper functions to compare logs. For now only index, term, and data
type are used. Data content comparison does not seem to be necessary for now.
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
Current election_timeout() helper might bump the term twice.
It's convenient and less error prone to have a more fine grained helper
that stops right when candidate state is reached.
Signed-off-by: Alejo Sanchez <alejo.sanchez@scylladb.com>
