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ccd623aa87
The repair process will potentially send ranges containing few mutations,
definitely not enough to fill a memtable. It wants to know whether or not each
of those ranges individually succeeded or failed, so we need a future for each.
Small memtables being flushed are bad, and we would like to write bigger
memtables so we can better utilize our disks.
One of the ways to fix that, is changing the repair itself to send more
mutations at a single batch. But relying on that is a bad idea for two reasons:
First, the goals of the SSTable writer and the repair sender are at odds. The
SSTable writer wants to write as few SSTables as possible, while the repair
sender wants to break down the range in pieces as small as it can and checksum
them individually, so it doesn't have to send a lot of mutations for no reason.
Second, even if the repair process wants to process larger ranges at once, some
ranges themselves may be small. So while most ranges would be large, we would
still have potentially some fairly small SSTables lying around.
The best course of action in this case is to coalesce the incoming streams
write-side. repair can now choose whatever strategy - small or big ranges - it
wants, resting assure that the incoming memtables will be coalesced together.
Signed-off-by: Glauber Costa <glauber@scylladb.com>
(cherry picked from commit 455d5a57d2)
#Scylla
##Building Scylla
In addition to required packages by Seastar, the following packages are required by Scylla.
Submodules
Scylla uses submodules, so make sure you pull the submodules first by doing:
git submodule init
git submodule update --recursive
Building and Running Scylla on Fedora
- Installing required packages:
sudo yum install yaml-cpp-devel lz4-devel zlib-devel snappy-devel jsoncpp-devel thrift-devel antlr3-tool antlr3-C++-devel libasan libubsan gcc-c++ gnutls-devel ninja-build ragel libaio-devel cryptopp-devel xfsprogs-devel numactl-devel hwloc-devel libpciaccess-devel libxml2-devel python3-pyparsing
- Build Scylla
./configure.py --mode=release --with=scylla --disable-xen
ninja-build build/release/scylla -j2 # you can use more cpus if you have tons of RAM
- 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>
Contributing to Scylla
Do not send pull requests.
Send patches to the mailing list address scylladb-dev@googlegroups.com. Be sure to subscribe.
In order for your patches to be merged, you must sign the Contributor's License Agreement, protecting your rights and ours. See http://www.scylladb.com/opensource/cla/.