incr command in Memcached is used to atomically increment a key's value. This is particularly useful in scenarios where you need to track counts or other numeric stats that might be frequently updated and accessed concurrently. Examples could include tracking page views, user votes, or any other counters.
Let's assume we have a Memcached instance up and running on localhost, port 11211. We'll use the 'dalli' gem, a popular Ruby client for Memcached.
Firstly, ensure you have dalli added to your Gemfile:
Now install it using Bundler:
In this example, we first set an initial value for our key 'counter'. Then we increment it by 1 twice, and each time we get the incremented value back.
incroperation only works when the key already exists.
incron non-numeric values. The
incroperation only works with numeric values.
incrto initialize a key if it does not exist; instead, it will just return nil.
Q: What happens if I try to increment a key that doesn't exist?
incr method will return nil if it cannot find the key.
Q: What happens if I use
incr on a key with string value?
incr method should only be used on keys with numeric values. If you try to increment a key associated with a string or non-numeric value, it won't work, and it might lead to unexpected behavior.