"
Recently it was discovered that the memtable reader
(partition_snapshot_reader to be more precise) can violate mutation
fragment monotonicity, by remitting range tombstones when those overlap
with more than one ck range of the partition slice.
This was fixed by 7049cd9, however after that fix was merged a much
simpler fix was proposed by Tomek, one that doesn't involve nearly as
much changes to the partition snapshot reader and hences poses less risk
of breaking it.
This mini-series reverts the previous fix, then applies the new, simpler
one.
Refs: #4104
"
* 'partition-snapshot-reader-simpler-fix/v2' of https://github.com/denesb/scylla:
partition_snapshot_reader: don't re-emit range tombstones overlapping multiple ck ranges
Revert "partition_snapshot_reader: don't re-emit range tombstones overlapping multiple ck ranges"
Committer: Avi Kivity <avi@scylladb.com>
Branch: next
Switch to the the CMake-ified Seastar
This change allows Scylla to be compiled against the `master` branch of
Seastar.
The necessary changes:
- Add `-Wno-error` to prevent a Seastar warning from terminating the
build
- The new Seastar build system generates the pkg-config files (for
example, `seastar.pc`) at configure time, so we don't need to invoke
Ninja to generate them
- The `-march` argument is no longer inherited from Seastar (correctly),
so it needs to be provided independently
- Define `SEASTAR_TESTING_MAIN` so that the definition of an entry
point is included for all unit test compilation units
- Independently link Scylla against Seastar's compiled copy of fmt in
its build directory
- All test files use the (now public) Seastar testing headers
- Add some missing Seastar headers to source files
[avi: regenerate frozen toolchain, adjust seastar submoule]
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <02141f2e1ecff5cbcd56b32768356c3bf62750c4.1548820547.git.jhaberku@scylladb.com>
When entering a new ck range (of the partition-slice), the partition
snapshot reader will apply to its range tombstones stream all the
tombstones that are relevant to the new ck range. When the partition has
range tombstones that overlap with multiple ck ranges, these will be
applied to the range tombstone stream when entering any of the ck ranges
they overlap with. This will result in the violation of the monotonicity
of the mutation fragments emitted by the reader, as these range
tombstones will be re-emitted on each ck range, if the ck range has at
least one clustering row they apply to.
For example, given the following partition:
rt{[1,10]}, cr{1}, cr{2}, cr{3}...
And a partition-slice with the following ck ranges:
[1,2], [3, 4]
The reader will emit the following fragment stream:
rt{[1,10]}, cr{1}, cr{2}, rt{[1,10]}, cr{3}, ...
Note how the range tombstone is emitted twice. In addition to violating
the monotonicity guarantee, this can also result in an explosion of the
number of emitted range tombstones.
Fix by trimming range tombstones to the start of the current ck range,
thus ensuring that they will not violate mutation fragment monotonicity
guarantees.
Refs: #4104
This is a much simpler fix for the above issue, than the already
committed one (7049cd937A). The latter is reverted by the previous
patch and this patch applies the simpler fix.
Replace stdx::optional and stdx::string_view with the C++ std
counterparts.
Some instances of boost::variant were also replaced with std::variant,
namely those that called seastar::visit.
Scylla now requires GCC 8 to compile.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
Message-Id: <20190108111141.5369-1-duarte@scylladb.com>
* seastar d59fcef...b924495 (2):
> build: Fix protobuf generation rules
> Merge "Restructure files" from Jesse
Includes fixup patch from Jesse:
"
Update Seastar `#include`s to reflect restructure
All Seastar header files are now prefixed with "seastar" and the
configure script reflects the new locations of files.
Signed-off-by: Jesse Haber-Kucharsky <jhaberku@scylladb.com>
Message-Id: <5d22d964a7735696fb6bb7606ed88f35dde31413.1542731639.git.jhaberku@scylladb.com>
"
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
Before this patch, maybe_merge_versions() had to be manually called
before partition snapshot goes away. That is error prone and makes
client code more complicated. Delegate that task to a new
partition_snapshot_ptr object, through which all snapshots are
published now.
Now all snapshots will have a mutation_cleaner which they will use to
gently destroy freed partition_version objects.
Destruction of memtable entries during cache update is also using the
gentle cleaner now. We need to have a separate cleaner for memtable
objects even though they're owned by cache's region, because memtable
versions must be cleared without a cache_tracker.
Each memtable will have its own cleaner, which will be merged with the
cache's cleaner when memtable is merged into cache.
Fixes some sources of reactor stalls on cache update when there are
large partition entries in memtables.
