57512d3df9
Affects single-partition reads only.
Refs #5113
When executing a query on the replica we do several things in order to
narrow down the sstable set we read from.
For tables which use LeveledCompactionStrategy, we store sstables in
an interval set and we select only sstables whose partition ranges
overlap with the queried range. Other compaction strategies don't
organize the sstables and will select all sstables at this stage. The
reasoning behind this is that for non-LCS compaction strategies the
sstables' ranges will typically overlap and using interval sets in
this case would not be effective and would result in quadratic (in
sstable count) memory consumption.
The assumption for overlap does not hold if the sstables come from
repair or streaming, which generates non-overlapping sstables.
At a later stage, for single-partition queries, we use the sstables'
bloom filter (kept in memory) to drop sstables which surely don't
contain given partition. Then we proceed to sstable indexes to narrow
down the data file range.
Tables which don't use LCS will do unnecessary I/O to read index pages
for single-partition reads if the partition is outside of the
sstable's range and the bloom filter is ineffective (Refs #5112).
This patch fixes the problem by consulting sstable's partition range
in addition to the bloom filter, so that the non-overlapping sstables
will be filtered out with certainty and not depend on bloom filter's
efficiency.
It's also faster to drop sstables based on the keys than the bloom
filter.
Tests:
- unit (dev)
- manual using cqlsh
Reviewed-by: Botond Dénes <bdenes@scylladb.com>
Message-Id: <20190927122505.21932-1-tgrabiec@scylladb.com>
(cherry picked from commit b0e0f29b06)
Scylla
Quick-start
$ git submodule update --init --recursive
$ sudo ./install-dependencies.sh
$ ./configure.py --mode=release
$ ninja-build -j4 # Assuming 4 system threads.
$ ./build/release/scylla
$ # Rejoice!
Please see HACKING.md for detailed information on building and developing Scylla.
Note: GCC >= 8.1.1 is require to compile Scylla.
Note: See frozen toolchain for a way to build and run on an older distribution.
Running Scylla
- Run Scylla
./build/release/scylla
- run Scylla with one CPU and ./tmp as data directory
./build/release/scylla --datadir tmp --commitlog-directory tmp --smp 1
- For more run options:
./build/release/scylla --help
Building Fedora RPM
As a pre-requisite, you need to install Mock on your machine:
# Install mock:
sudo yum install mock
# Add user to the "mock" group:
usermod -a -G mock $USER && newgrp mock
Then, to build an RPM, run:
./dist/redhat/build_rpm.sh
The built RPM is stored in /var/lib/mock/<configuration>/result directory.
For example, on Fedora 21 mock reports the following:
INFO: Done(scylla-server-0.00-1.fc21.src.rpm) Config(default) 20 minutes 7 seconds
INFO: Results and/or logs in: /var/lib/mock/fedora-21-x86_64/result
Building Fedora-based Docker image
Build a Docker image with:
cd dist/docker
docker build -t <image-name> .
Run the image with:
docker run -p $(hostname -i):9042:9042 -i -t <image name>