Currently the test does not wait for cache update
to finish before carrying on with the checks.
This makes the test nondeterministic and purely wrong
because checks expect update to be finished.
This patch changes the test to wait for update to finish.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <2a99bba24b1628466d3495332b48ef3ccdb43c26.1485862389.git.piotr@scylladb.com>
partition_range passed to row_cache::make_reader
has to be kept alive as long as the resulting reader
is used.
Otherwise weird things start to happen.
This used to work just because of a pure luck.
When I started changing the row_cache implementation
I run into very weird behaviors for this tests.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <2c9e337dbbcf35f4e1394cad043eda10b8c2bd4a.1478602876.git.piotr@scylladb.com>
Wrapping ranges are a pain, so we are moving wrap handling to the edges.
Since cql can't generate wrapping ranges, this means thrift and the ring
maintenance code; also range->ring transformations need to merge the first
and last ranges.
Message-Id: <1478105905-31613-1-git-send-email-avi@scylladb.com>
Originally, cache tests checked how many times a mutation reader was
created from the underlying mutation source to determine whether
continuity flag is working correctly.
This is not going to work with fast forwarding mutation readers so the
test is switched to count number of mutations (+ end of stream markers)
returned from underlying mutaiton readers which is much less fragile.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
This reverts commit 1726b1d0cc.
Reverting this patch turns our SSTable access counter into a miss counter only.
The estimated histogram always starts its first bucket at 1, so by marking cache
accesses we will be wrongly feeding "1" into the buckets.
Notice that this is not yet ideal: nodetool is supposed to show a histogram of
all reads, and by doing this we are changing its meaning slightly. Workloads
that serve mostly from cache will be distorted towards their misses.
The real solution is to use a different histogram, but we will need to enforce
a newer version of nodetool for that: the current issue is that nodetool expects
an EstimatedHistogram in a specific format in the other side.
Conflicts:
row_cache.hh
Message-Id: <a599fa9e949766e7c9697450ae34fc28e881e90a.1472742276.git.glauber@scy
lladb.com>
Signed-off-by: Glauber Costa <glauber@scylladb.com>
If we have a cache hit, we still need to update our sstable histogram - notting
that we have touched 0 SSTables.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Remove clustering_key_filter_factory and clustering_key_filtering_context.
Use partition_slice directly with a static get_ranges method.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Once we encounter a wide partition store information
about this in cache entry and don't try to read it all
and cache next time it's requested.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
[Paweł: rebased, moved large partition reading logic to
cache_entry::read_wide()]
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
In case of failure BOOST_REQUIRE_EQUAL() is nicer and prints the actual
values that were supposed to be equal, but aren't.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Add contiguity flag to cache entry and set it in scanning reader.
Partitions fetched during scanning are continuous
and we know there's nothing between them.
Clear contiguity flag on cache entries
when the succeeding entry is removed.
Use continuous flag in range queries.
Don't go do disk if we know that there's nothing
between two entries we have in cache. We know that
when continuous flag of the first one is set to true.
Signed-off-by: Piotr Jastrzebski <piotr@scylladb.com>
Message-Id: <72bae432717037e95d1ac9465deaccfa7c7da707.1466627603.git.piotr@scylladb.com>
Correctness of current uses of clear() and invalidate() relies on fact
that cache is not populated using readers created before
invalidation. Sstables are first modified and then cache is
invalidated. This is not guaranteed by current implementation
though. As pointed out by Avi, a populating read may race with the
call to clear(). If that read started before clear() and completed
after it, the cache may be populated with data which does not
correspond to the new sstable set.
To provide such guarantee, invalidate() variants were adjusted to
synchronize using _populate_phaser, similarly like row_cache::update()
does.
row_cache::update() does not explicitly invalidate the entries it failed
to update in case of a failure. This could lead to inconsistency between
row cache and sstables.
In paractice that's not a problem because before row_cache::update()
fails it will cause all entries in the cache to be invalidated during
memory reclaim, but it's better to be safe and explicitly remove entries
that should be updated but it was not possible to do so.
Signed-off-by: Paweł Dziepak <pdziepak@scylladb.com>
Message-Id: <1453829681-29239-1-git-send-email-pdziepak@scylladb.com>
Its definition as a lambda function is inconvenient, because it does not allow
us to use default values for parameters.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
Its definition as a lambda function is inconvenient, because it does not allow
us to use default values for parameters.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
The intent is to make data returned by queries always conform to a
single schema version, which is requested by the client. For CQL
queries, for example, we want to use the same schema which was used to
compile the query. The other node expects to receive data conforming
to the requested schema.
Interface on shard level accepts schema_ptr, across nodes we use
table_schema_version UUID. To transfer schema_ptr across shards, we
use global_schema_ptr.
Because schema is identified with UUID across nodes, requestors must
be prepared for being queried for the definition of the schema. They
must hold a live schema_ptr around the request. This guarantees that
schema_registry will always know about the requested version. This is
not an issue because for queries the requestor needs to hold on to the
schema anyway to be able to interpret the results. But care must be
taken to always use the same schema version for making the request and
parsing the results.
Schema requesting across nodes is currently stubbed (throws runtime
exception).
The underlying data source for cache should not be the same memtable
which is later used to update the cache from. This fixes the following
assertion failure:
row_cache_test_g: utils/logalloc.hh:289: decltype(auto) logalloc::allocating_section::operator()(logalloc::region&, Func&&) [with Func = memtable::make_reader(schema_ptr, const partition_range&)::<lambda()>]: Assertion `r.reclaiming_enabled()' failed.
The problem is that when memtable is merged into cache their regions
are also merged, so locking cache's region locks the memtable region
as well.
Since bytes is a very generic value that is returned from many calls,
it is easy to pass it by mistake to a function expecting a data_value,
and to get a wrong result. It is impossible for the data_value constructor
to know if the argument is a genuine bytes variable, a data_value of another
type, but serialized, or some other serialized data type.
To prevent misuse, make the data_value(bytes) constructor
(and complementary data_value(optional<bytes>) explicit.
