I'm trying to push an entry in a list in Redis and also want to update the TTL of the list every time a new entry comes in. I can do that my simple calling the EXPIRE "my-list" ttl using Redis. Since my application is receiving heavy traffic, I want to reduce the number of calls to redis.
Can I set my TTL during the push operation in Redis, i.e RPUSH "mylist" I1 I2...IN ex "TTL", does redis support this time of command functionality. I can see that it does support this for the String data structures.
Redis does not have dedicated commands to push and expire the List, although as you've mentioned it does have something like that for the String data type.
The way you'd go about this challenge is to compose your own "command" from existing ones. Instead of having your application call these commands, however, you would use a Lua script as explained in the EVAL documentation page.
Lua scripts are cached and run atomically on the server. One such as the following would probably help in your case - it expects to get the key name, the pushed element and the expiry value:
local reply = redis.call('RPUSH', KEYS[1], ARGV[1])
redis.call('EXPIRE', KEYS[1], ARGV[2])
return reply