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>
Recently we had a bug (#4096) due to a component
(`multishard_mutation_query()`) assuming that all reads used the
semaphore obtainable via `database::user_read_concurrency_sem()`.
This problem revealed that it is plain wrong to allow access to the
shard-global semaphores residing in the database object. Instead all
code wishing to access the relevant semaphore for some read, should do
so via the relevant `table` object, thus guaranteeing that it will get
the correct semaphore, configured for that table.
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <4f3a6780eb3240822db34aba7c1ba0a675a96592.1547734212.git.bdenes@scylladb.com>
"
This mini-series adds counters for the inactive reads registered in the
reader concurrency semaphore.
"
* 'reader-concurrency-semaphore-counters/v6' of https://github.com/denesb/scylla:
tests/querier_cache: use stats to get the no. of inactive reads
reader_concurrency_semaphore: add counters for inactive reads
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>
Now that we added stats for the inactive reads, the tests don't need
the `reader_concurrency_semaphore::inactive_reads()` method, instead
they can rely on the stats to check the number of inactive reads.
Simplify the fix for memory based eviction, introduced by 918d255 so
there is no need to massage the counters.
Also add a check to `test_memory_based_cache_eviction` which checks for
the bug fixed. While at it also add a check to
`test_time_based_cache_eviction` for the fix to time based eviction
(e5a0ea3).
Tests: tests/querier_cache:debug
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <c89e2788a88c2a701a2c39f377328e77ac01e3ef.1546515465.git.bdenes@scylladb.com>
The reader concurrency semaphore can evict the querier when it is
registered as an inactive read. Make the `querier_cache` aware of this
so that it doesn't continue to process the inserted querier when this
happens.
Also add a unit test for this.
Previously there was a type mismatch for `count` and `memory`, between
the actual type used to store them in the class (signed) and the type
of the parameters in the constructor (unsigned).
Although negative numbers are completely valid for these members,
initializing them to negative numbers don't make sense, this is why they
used unsigned types in the constructor. This restriction can backfire
however when someone intends to give these parameters the maximum
possible value, which, when interpreted as a signed value will be `-1`.
What's worse the caller might not even be aware of this unsigned->signed
conversion and be very suprised when they find out.
So to prevent surprises, expose the real type of these members, trusting
the clients of knowing what they are doing.
Also add a `no_limits` constructor, so clients don't have to make sure
they don't overflow internal types.
Instead, distribute those inclusions to .cc files that require them. This
reduces rebuilds when config.hh changes, and makes it easier to locate files
that need config disaggregation.
Both of these have the same problem. They remove the to-be-evicted
entries from `_entries` but they don't unregister the `entry` from the
`read_concurrency_semaphore`. This results in the
`reader_concurrency_semaphore` being left with a dangling pointer to the
entries will trigger segfault when it tries to evict the associated
inactive reads.
Also add a unit test for `evict_all_for_table()` to check that it works
properly (`evict_one()` is only used in tests, so no dedicated test for
it).
Fixes: #3962
Signed-off-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <57001857e3791c6385721b624d33b667ccda2e7d.1544010868.git.bdenes@scylladb.com>
Currently when this test fails, resources are not released in the
correct order, which results in ASAN complaining about use-after-free
in debug builds. This is due to the BOOST_REQUIRE macro aborting the
test when the predicate fails, not allowing for correct destruction
order to take place.
To avoid this ugly failure, that adds noise and might cause a developer
investigating into the failure starting on the wrong path, use the more
mild BOOST_CHECK family of test macros. These will allow the test to run
to completion even when the predicate fails, allowing for the correct
destruction of the resources.
Now that we have an accessor for all concurrency semaphores, we don't
need the tricks of creating a dummy keyspace to get them. Use the
accessors instead.
As we are about to add multiple sources of evictable readers, we need a
more scalable solution than a single functor being passed that opaquely
evicts a reader when called.
Add a generic way to register and unregister evictable (inactive)
readers to the semaphore. The readers are expected to be registered when
they become evictable and are expected to be unregistered when they
cease to become evictable. The semaphore might evict any reader that is
registered to it, when it sees fit.
This also solves the problem of notifying the semaphore when new readers
become evictable. Previously there was no such mechanism, and the
semaphore would only evict any such new readers when a new permit was
requested from it.
sprint() recently became more strict, throwing on sprint("%s", 5). Replace
with the more modern format().
Mechanically converted with https://github.com/avikivity/unsprint.
Instead of hiding what compaction method the querier uses (and only
expose it via rejecting 'can_be_used_for_page()`) make it very explicit
that these are really two different queriers. This allows using
different indexes for the two queriers in `querier_cache` and
eliminating the possibility of picking up a querier with the wrong
compaction method (read kind).
This also makes it possible to add new querier type(s) that suit the
multishard-query's needs without making a confusing mess of `querier` by
making it a union of all querying logic.
Splitting the queriers this way changes what happens when a lookup finds
a querier of the wrong kind (e.g. emit_only_live::yes for an
emit_only_live::no command). As opposed to dropping the found (but
wrong) querier the querier will now simply not be found by the lookup.
This is a result of using separate search indexes for the different
mutation kinds. This change should have no practical implications.
Splitting is done by making querier templated on `emit_only_live_rows`.
It doesn't make sense to duplicate the entire querier as the two share
99% of the code.
Requiring the caller of lookup() to pass in a `create_fun()` was not
such a good idea in hindsight. It leads to awkward call sites and even
more awkward code when trying to find out whether the lookup was
successfull or not.
Returning an optional gives calling code much more flexibility and makes
the code cleaner.
Do increment the key counter after inserting the first querier into the
cache. Otherwise two queriers with the same key will be inserted and
will fail the test. This problem is exposed by the changes the next
patches make to the querier-cache but will be fixed before to maintain
bisectability of the code.
Fixes: #3529
