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>
We add a cluster feature that informs whether the xxHash algorithm is
supported, and allow nodes to switch to it. We use a cluster feature
because older versions are not ready to receive a different digest
algorithm than MD5 when answering a data request.
If we ever should add a new hash algorithm, we would also need to
add a new cluster feature for that algorithm. The alternative would be
to add code so a coordinator could negotiate what digest algorithm to
use with the set of replicas it is contacting.
Fixes#2884
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
If we're talking to just one replica, the digest is not going to be used,
so better not to calculate it at all. The optimization helps with
LOCAL_ONE queries where the result is large, but does not contain large
blobs (many small rows).
This patch adds a digest_algorithm parameter to the READ_DATA verb that
can take on two values: none and MD5 (default), and sets it to none when
we're reading from one replica.
In the future we may add other values for more hardware-friendly digest
algorithms.
Message-Id: <1479380600-19206-1-git-send-email-avi@scylladb.com>
This patch adds support to send a cell's ttl as part of a query's
result. This is needed for thrift support.
Signed-off-by: Duarte Nunes <duarte@scylladb.com>
The query result footprint for cassandra-stress mutation as reported
by tests/memory-footprint increased by 18% from 285 B to 337 B.
perf_simple_query shows slight regression in throughput (-8%):
build/release/tests/perf/perf_simple_query -c4 -m1G --partitions 100000
Before: ~433k tps
After: ~400k tps
