Redis command to get all available channels for pub/sub?
PUBSUB CHANNELS does this as of version 2.8.0.
redis
How to know master/slave status of redis?
The INFO command returns the current role. e.g/ if we’re the master role:master will be shown, amongst other details. And if we switch to a slave, maybe by using slaveof: slaveof 192.168.1.66 6379 We get more, when we run INFO: role:slave master_host:192.168.1.66 master_port:6379 master_link_status:down master_last_io_seconds_ago:-1 master_sync_in_progress:0 master_link_down_since_seconds:1341313174 EDIT: Here’s a succinct cli command as shown … Read more
Redis: Failed opening .rdb for saving: Permission denied
You should check your redis.conf file to see the permissions in dir and dbfilename. If the file named in the dbfilename which is located in the path specified in the dir path exists and the permission is also right. then the problem should be fixed. Hope this will help someone. P.S. To find the redis.conf … Read more
Stop redis server. Neither shutdown nor stop works
I finally got it down. Get the PID of the process (this worked in Webfaction): ps -u my_account -o pid,rss,command | grep redis Then > kill -9 the_pid I was able to REPRODUCE this issue: Start redis-server Then break it using Pause/Break key Now it hangs and it won’t shutdown normally. Also the Python program … Read more
Redis Multi-Set With a TTL
I was also looking for this kind of operation. I didn’t find anything, so I did it with MULTI/EXEC: MULTI expire key1 expire key2 expire key3 EXEC
SCAN vs KEYS performance in Redis
You shouldn’t care about current command execution but about the impact to all other commands, since Redis processes commands using a single thread (i.e. while a command is being executed all others need to await until executing one ends). While keys or scan might provide you similar or identical performance executed alone in your case, … Read more
Redis / Get all keys & values from redis with prefix
HGETALL returns all fields and values of the hash stored at key, you can’t specify a mask: http://redis.io/commands/hgetall You can call KEYS doc:* to get a list of all keys matching your criteria and then get all values in a loop. But please read a section on potential performance hit before you do that: http://redis.io/commands/keys
Redis vs RocksDB
They have nothing in common. You are trying to compare apples and oranges here. Redis is a remote in-memory data store (similar to memcached). It is a server. A single Redis instance is very efficient, but totally non scalable (regarding CPU). A Redis cluster is scalable (regarding CPU). RocksDB is an embedded key/value store (similar … Read more
Redis is configured to save RDB snapshots, but is currently not able to persist on disk
When installing with brew the logfile is set to stdout. You need to edit /usr/local/etc/redis.conf and change logfile to something else. I set mine to: logfile /var/log/redis-server.log You’ll also make sure the user that runs redis has write permissions to the logfile, or redis will simply fail to launch completely. Then just restart redis: brew … Read more
Redis bind to more than one IP
Binding to multiple IPs is indeed possible since Redis 2.8. Just separate each IP by whitespace (not commas). bind 127.0.0.1 123.33.xx.xx Source: Official default config