Dynomite

Dynomite, inspired by Dynamo whitepaper, is a thin, distributed dynamo layer for different storage engines and protocols. Currently these include Redis and Memcached. Dynomite supports multi-datacenter replication and is designed for high availability.


The ultimate goal with Dynomite is to be able to implement high availability and cross-datacenter replication on storage engines that do not inherently provide that functionality. The implementation is efficient, not complex (few moving parts), and highly performant.

Workflow

The stable version of Dynomite is the master branch.

For questions or contributions, please consider reading CONTRIBUTING.md.

Build

To build Dynomite from source with debug logs enabled and assertions disabled:

$ git clone git@github.com:Netflix/dynomite.git
$ cd dynomite
$ autoreconf -fvi
$ ./configure --enable-debug=yes
$ make
$ src/dynomite -h

To build Dynomite in debug mode:

$ git clone git@github.com:Netflix/dynomite.git
$ cd dynomite
$ autoreconf -fvi
$ CFLAGS="-ggdb3 -O0" ./configure --enable-debug=full
$ make
$ sudo make install

Help

Usage: dynomite [-?hVdDt] [-v verbosity level] [-o output file]
                  [-c conf file] [-s stats port] [-a stats addr]
                  [-i stats interval] [-p pid file] [-m mbuf size]
                  [-M max alloc messages]

Options:
  -h, --help             : this help
  -V, --version          : show version and exit
  -t, --test-conf        : test configuration for syntax errors and exit
  -d, --daemonize        : run as a daemon
  -D, --describe-stats   : print stats description and exit
  -v, --verbosity=N      : set logging level (default: 5, min: 0, max: 11)
  -o, --output=S         : set logging file (default: stderr)
  -c, --conf-file=S      : set configuration file (default: /etc/dynomitedb/dynomite.yaml)
  -s, --stats-port=N     : set stats monitoring port (default: 22222)
  -a, --stats-addr=S     : set stats monitoring ip (default: 0.0.0.0)
  -i, --stats-interval=N : set stats aggregation interval in msec (default: 30000 msec)
  -p, --pid-file=S       : set pid file (default: off)
  -m, --mbuf-size=N      : set size of mbuf chunk in bytes (default: 16384 bytes)
  -M, --max-msgs=N       : set max number of messages to allocate (default: 2000000)

Configuration

Dynomite can be configured through a YAML file specified by the -c or --conf-file command-line argument on process start. The configuration files parses and understands the following keys:

• env: Specify environment of a node. Currently supports aws and network (for physical datacenter).
• datacenter: The name of the datacenter. Please refer to architecture document.
• rack: The name of the rack. Please refer to architecture document.
• dyn_listen: The port that dynomite nodes use to inter-communicate and gossip.
• gos_interval: The sleeping time in milliseconds at the end of a gossip round.
• tokens: The token(s) owned by a node. Currently, we don't support vnode yet so this only works with one token for the time being.
• dyn_seed_provider: A seed provider implementation to provide a list of seed nodes.
• dyn_seeds: A list of seed nodes in the format: address:port:rack:dc:tokens (node that vnode is not supported yet)
• listen: The listening address and port (name:port or ip:port) for this server pool.
• timeout: The timeout value in msec that we wait for to establish a connection to the server or receive a response from a server. By default, we wait indefinitely.
• preconnect: A boolean value that controls if dynomite should preconnect to all the servers in this pool on process start. Defaults to false.
• data_store: An integer value that controls if a server pool speaks redis (0) or memcached (1) or other protocol. Defaults to redis (0).
• server_connections: The maximum number of connections that can be opened to each server. By default, we open at most 1 server connection.
• auto_eject_hosts: A boolean value that controls if server should be ejected temporarily when it fails consecutively server_failure_limit times. See liveness recommendations for information. Defaults to false.
• server_retry_timeout: The timeout value in msec to wait for before retrying on a temporarily ejected server, when auto_eject_host is set to true. Defaults to 30000 msec.
• server_failure_limit: The number of consecutive failures on a server that would lead to it being temporarily ejected when auto_eject_host is set to true. Defaults to 2.
• servers: A list of local server address, port and weight (name:port:weight or ip:port:weight) for this server pool. Usually there is just one.
• secure_server_option: Encrypted communication. Must be one of 'none', 'rack', 'datacenter', or 'all'.

For example, the configuration file in /etc/dynomitedb/dynomite.yaml

Finally, to make writing syntactically correct configuration files easier, dynomite provides a command-line argument -t or --test-conf that can be used to test the YAML configuration file for any syntax error.

License

Licensed under the Apache License, Version 2.0: http://www.apache.org/licenses/LICENSE-2.0