I suggest you read about this on http://redis.io/topics/persistence . Basically you lose the guaranteed persistence when you increase performance by using only in-memory storing. Imagine a scenario where you INSERT into memory, but before it gets persisted to disk lose power. There will be data loss. Redis supports so-called “snapshots”. This means that it will … Read more
First, create a dump on server A. A$ redis-cli 127.0.0.1:6379> CONFIG GET dir 1) “dir” 2) “/var/lib/redis/” 127.0.0.1:6379> SAVE OK This ensures dump.rdb is completely up-to-date, and shows us where it is stored (/var/lib/redis/dump.rdb in this case). dump.rdb is also periodically written to disk automatically. Next, copy it to server B: A$ scp /var/lib/redis/dump.rdb myuser@B:/tmp/dump.rdb … Read more
You can issue the INFO command, which returns information and statistics about the server. See here for an example output. As mentioned in the comments by mVChr, you can use info keyspace directly on the redis-cli. redis> INFO # Server redis_version:6.0.6 redis_git_sha1:00000000 redis_git_dirty:0 redis_build_id:b63575307aaffe0a redis_mode:standalone os:Linux 5.4.0-1017-aws x86_64 arch_bits:64 multiplexing_api:epoll atomicvar_api:atomic-builtin gcc_version:9.3.0 process_id:2854672 run_id:90a5246f10e0aeb6b02cc2765b485d841ffc924e tcp_port:6379 … Read more
redis-cli -h XXX.XXX.XXX.XXX -p YYYY xxx.xxx.xxx.xxx is the IP address and yyyy is the port EXAMPLE from my dev environment redis-cli -h 10.144.62.3 -p 30000 REDIS CLI COMMANDS Host, port, password and database By default redis-cli connects to the server at 127.0.0.1 port 6379. As you can guess, you can easily change this using command … Read more
Rough results from the following benchmark: 2x write, 3x read. Here’s a simple benchmark in python you can adapt to your purposes, I was looking at how well each would perform simply setting/retrieving values: #!/usr/bin/env python2.7 import sys, time from pymongo import Connection import redis # connect to redis & mongodb redis = redis.Redis() mongo … Read more
After installing redis, type from terminal: redis-server And Redis-Server will be started
Well it depends on how you define concurrency. In server-side software, concurrency and parallelism are often considered as different concepts. In a server, supporting concurrent I/Os means the server is able to serve several clients by executing several flows corresponding to those clients with only one computation unit. In this context, parallelism would mean the … Read more
You don’t want to use multiple databases in a single redis instance. As you noted, multiple instances lets you take advantage of multiple cores. If you use database selection you will have to refactor when upgrading. Monitoring and managing multiple instances is not difficult nor painful. Indeed, you would get far better metrics on each … Read more
There is no command to do it (like you would do it with MySQL for instance). The number of Redis databases is fixed, and set in the configuration file. By default, you have 16 databases. Each database is identified by a number (not a name). You can use the following command to know the number … Read more
$ redis-server –version gives you the version.