How to purge data older than 30 days from Redis Server - redis

Question

I am using Logstash, Redis DB, ElasticSearch and Kibana 3 for my centalize log server. It's working fine and I am able to see the logs in Kibana. Now I want to keep only 30 days log in ElasticSearch and Redis Server. Is it possible to purge data from Redis?
I am using the below configuration
indexer.conf
input {
redis {
host => "127.0.0.1"
port => 6379
type => "redis-input"
data_type => "list"
key => "logstash"
format => "json_event"
}
}
output {
stdout { debug => true debug_format => "json"}
elasticsearch {
host => "127.0.0.1"
}
}
shipper.conf
input {
file {
type => "nginx_access"
path => ["/var/log/nginx/**"]
exclude => ["*.gz", "error.*"]
discover_interval => 10
}
}
filter {
grok {
type => nginx_access
pattern => "%{COMBINEDAPACHELOG}"
}
}
output {
stdout { debug => true debug_format => "json"}
redis { host => "127.0.0.1" data_type => "list" key => "logstash" }
}
As per this configuration the shipper file is sending data to Redis DB with the key "logstash". From the redis db documents I came to know that we can set TTL for any key with expire command to purge them. But when I am searching for the key "logstash" in redis db keys logstash or keys *I am not getting any result. Please let me know if my question is not understandable. Thanks in advance.

Answer 1

Redis is a key:value store. Keys are unique by definition. So if you want to store several logs, you need to add a new entry, with a new key and associated value, for each log.
So it seems to me you have a fundamental flaw here, as you're always using the same key for all your logs. Try with a different key for each log (not sure how to do that).
Then set TTL to 30 days.