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Starting with Redis 2.8 masters are able to detect timed out slaves, while before 2.8 only slaves were able to detect a timed out master. Now that timeout detection is bi-directional the following problem happens as described "in the field" by issue #1449: 1) Master and slave setup with big dataset. 2) Slave performs the first synchronization, or a full sync after a failed partial resync. 3) Master sends the RDB payload to the slave. 4) Slave loads this payload. 5) Master detects the slave as timed out since does not receive back the REPLCONF ACK acknowledges. Here the problem is that the master has no way to know how much the slave will take to load the RDB file in memory. The obvious solution is to use a greater replication timeout setting, but this is a shame since for the 0.1% of operation time we are forced to use a timeout that is not what is suited for 99.9% of operation time. This commit tries to fix this problem with a solution that is a bit of an hack, but that modifies little of the replication internals, in order to be back ported to 2.8 safely. During the RDB loading time, we send the master newlines to avoid being sensed as timed out. This is the same that the master already does while saving the RDB file to still signal its presence to the slave. The single newline is used because: 1) It can't desync the protocol, as it is only transmitted all or nothing. 2) It can be safely sent while we don't have a client structure for the master or in similar situations just with write(2).
Where to find complete Redis documentation? ------------------------------------------- This README is just a fast "quick start" document. You can find more detailed documentation at http://redis.io Building Redis -------------- Redis can be compiled and used on Linux, OSX, OpenBSD, NetBSD, FreeBSD. We support big endian and little endian architectures. It may compile on Solaris derived systems (for instance SmartOS) but our support for this platform is "best effort" and Redis is not guaranteed to work as well as in Linux, OSX, and *BSD there. It is as simple as: % make You can run a 32 bit Redis binary using: % make 32bit After building Redis is a good idea to test it, using: % make test 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" Allocator --------- Selecting a non-default memory allocator when building Redis is done by setting the `MALLOC` environment variable. Redis is compiled and linked against libc malloc by default, with the exception of jemalloc being the default on Linux systems. This default was picked because jemalloc has proven to have fewer fragmentation problems than libc malloc. To force compiling against libc malloc, use: % make MALLOC=libc To compile against jemalloc on Mac OS X systems, use: % make MALLOC=jemalloc 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 here: 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 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!
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