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1e37e1d40c
Refs #3929 Optionally enables O_DSYNC mode for segment files, and when enabled ignores actual flushing and just barriers any ongoing writes. Iff using O_DSYNC mode, we will not only truncate the file to max size, but also do an actual initial write of zero:s to it, since XFS (intended target) has observably less good behaviour on non-physical file blocks. Once written (and maybe recycled) we should have rather satisfying throughput on writes. Note that the O_DSYNC behaviour is hidden behind a default disabled option. While user should probably seldom worry about this, we should add some sort of logic i main/init that unless specified by user, evaluates the commitlog disk and sets this to true if it is using XFS and looks ok. This is because using O_DSYNC on things like EXT4 etc has quite horrible performance. All above statements about performance and O_DSYNC behaviour are based on a sampling of benchmark results (modified fsqual) on a statistically non-ssignificant selection of disks. However, at least there the observed behaviour is a rather large difference between ::fallocate:ed disk area vs. actually written using O_DSYNC on XFS, and O_DSYNC on EXT4. Note also that measurements on O_DSYNC vs. no O_DSYNC does not take into account the wall-clock time of doing manual disk flush. This is intentionally ignored, since in the commitlog case, at least using periodic mode, flushes are relatively rare. Message-Id: <20190520120331.10229-1-calle@scylladb.com>
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>