ND-Hedis

NVM-DRAM Hybrid Redis (ND-Hedis)
Implemented by totorody.

To build ND-Hedis with PMDK run command

% make USE_PMDK=yes TODIS=yes STD=-std=gnu99

Run ND-Hedis server (root)

% PMEM_IS_PMEM_FORCE=1 ./src/redis-server ${some-configuration-file}

Publications (Best Poster Awards)

Doyoung Kim, Won Gi Choi, Hanseung Sung, and Sanghyun Park, A scalable and persistent key-value store using non-volatile memory, In Proceedings of the 34th ACM/SIGAPP Symposium on Applied Computing (SAC '19), Limassol-Cyprus, Apr 2019, pp. 464-467

https://dl.acm.org/citation.cfm?id=3298991

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This README is just a fast quick start document. You can find more detailed documentation at http://redis.io.

What is Redis?

Redis is often referred as a data structures server. What this means is that Redis provides access to mutable data structures via a set of commands, which are sent using a server-client model with TCP sockets and a simple protocol. So different processes can query and modify the same data structures in a shared way.

Data structures implemented into Redis have a few special properties:

• Redis cares to store them on disk, even if they are always served and modified into the server memory. This means that Redis is fast, but that is also non-volatile.
• Implementation of data structures stress on memory efficiency, so data structures inside Redis will likely use less memory compared to the same data structure modeled using an high level programming language.
• Redis offers a number of features that are natural to find in a database, like replication, tunable levels of durability, cluster, high availability.

Another good example is to think of Redis as a more complex version of memcached, where the operations are not just SETs and GETs, but operations to work with complex data types like Lists, Sets, ordered data structures, and so forth.

If you want to know more, this is a list of selected starting points:

• Introduction to Redis data types. http://redis.io/topics/data-types-intro
• Try Redis directly inside your browser. http://try.redis.io
• The full list of Redis commands. http://redis.io/commands
• There is much more inside the Redis official documentation. http://redis.io/documentation

Redis with Persistent Memory

This is modified version of Redis, which benefits from Persistent Memory and uses PMDK (Persistent Memory Development Kit) libpmemobj API to allocate objects managed in Redis. Key-value pairs are created in Persistent Memory pool specified by "pmfile" parameter in config file. Currently, only simple structures: strings for keys and values can be allocated in Persistent Memory. Lists, sets etc. are not supported yet. Allocations are done with transactional API provided by PMDK libpmemobj library. When PMEM mode is configured and turned-on, all other built-in persistence mechanisms (RDB, AOF) are disabled. To build Redis with PM support, it is necessary to place PMDK Library in /deps/pmdk directory. Check http://pmem.io/pmdk for information about PMDK and on how to retrieve its sources.

Due to PMDK requirements, compilation must be done with "-std=gnu99" option. To build Redis with PMDK run command:

% make USE_PMDK=yes STD=-std=gnu99

After building Redis is a good idea to test it, using:

% make test

Fixing build problems with dependencies or cached build options

Redis has some dependencies which are included into the deps directory. make does not rebuild dependencies automatically, even if something in the source code of dependencies is changed.

When you update the source code with git pull or when code inside the dependencies tree is modified in any other way, make sure to use the following command in order to really clean everything and rebuild from scratch:

make distclean

This will clean: jemalloc, lua, hiredis, linenoise.

Also if you force certain build options like 32bit target, no C compiler optimizations (for debugging purposes), and other similar build time options, those options are cached indefinitely until you issue a make distclean command.

Fixing problems building 32 bit binaries

If after building Redis with a 32 bit target you need to rebuild it with a 64 bit target, or the other way around, you need to perform a make distclean in the root directory of the Redis distribution.

In case of build errors when trying to build a 32 bit binary of Redis, try the following steps:

• Install the packages libc6-dev-i386 (also try g++-multilib).
• Try using the following command line instead of make 32bit: make CFLAGS="-m32 -march=native" LDFLAGS="-m32"

Verbose build

Redis will build with a user friendly colorized output by default. If you want to see a more verbose output use the following:

% make V=1

Running Redis

To run Redis with the default configuration just type:

% cd src
% ./redis-server

If you want to provide your redis.conf, you have to run it using an additional parameter (the path of the configuration file):

% cd src
% ./redis-server /path/to/redis.conf

It is possible to alter the Redis configuration passing parameters directly as options using the command line. Examples:

% ./redis-server --port 9999 --slaveof 127.0.0.1 6379
% ./redis-server /etc/redis/6379.conf --loglevel debug

All the options in redis.conf are also supported as options using the command line, with exactly the same name.

Playing with Redis

You can use redis-cli to play with Redis. Start a redis-server instance, then in another terminal try the following:

% cd src
% ./redis-cli
redis> ping
PONG
redis> set foo bar
OK
redis> get foo
"bar"
redis> incr mycounter
(integer) 1
redis> incr mycounter
(integer) 2
redis>

You can find the list of all the available commands at http://redis.io/commands.

Installing Redis

In order to install Redis binaries into /usr/local/bin just use:

% make install

You can use make PREFIX=/some/other/directory install if you wish to use a different destination.

Make install will just install binaries in your system, but will not configure init scripts and configuration files in the appropriate place. This is not needed if you want just to play a bit with Redis, but if you are installing it the proper way for a production system, we have a script doing this for Ubuntu and Debian systems:

% cd utils
% ./install_server.sh

The script will ask you a few questions and will setup everything you need to run Redis properly as a background daemon that will start again on system reboots.

You'll be able to stop and start Redis using the script named /etc/init.d/redis_<portnumber>, for instance /etc/init.d/redis_6379.

Code contributions

Note: by contributing code to the Redis project in any form, including sending a pull request via Github, a code fragment or patch via private email or public discussion groups, you agree to release your code under the terms of the BSD license that you can find in the COPYING file included in the Redis source distribution.

Please see the CONTRIBUTING file in this source distribution for more information.

Enjoy!