In a web application, caching is used to speed up repeated queries and reduce database load. However, there might be scenarios where you need to delete the cache. For instance:
The following examples use the redis
gem for Ruby.
require 'redis' redis = Redis.new redis.set('key', 'value') # sets a value dis.delete('key') # deletes the key-value pair
This will remove the key 'key' from the Redis store.
require 'redis' redis = Redis.new redis.mset('key1', 'value1', 'key2', 'value2') # sets multiple values redis.del('key1', 'key2') # deletes multiple keys at once
This will remove both 'key1' and 'key2' from the Redis store.
require 'redis' redis = Redis.new redis.flushdb
This command will empty the entire Redis store.
Instead of deleting the entire cache, selectively delete keys as this can help avoid unnecessary database load.
Avoid using flushdb or flushall in production as they will lock your Redis instance while it clears the database.
Not handling exceptions when deleting keys. Ensure you are using proper error handling to avoid breaking the application in case a key isn't found or the Redis server is down.
Using flushall
instead of flushdb
. The flushall
command not only deletes data from the current database but also from all other databases on the same Redis instance.
keys
method and then delete them. For example:require 'redis' redis = Redis.new keys = redis.keys('*pattern*') keys.each { |key| redis.del(key) }
However, be aware that using keys
can potentially block the server for a long time if called against large databases.
Dragonfly is fully compatible with the Redis ecosystem and requires no code changes to implement.