Unbounded script cache may lead to running out of memory if a large number of scripts is generated on the client based on user input, time, or any other changing variables with unbounded range of values. To reproduce, start elasticsearch with 32M heap and run the following script for a few minutes: https://gist.github.com/7163ea88b52018cdb66c.

The script cache parameters should be configurable using the following settings:

• script.cache.size - allows to specify the maximum number of compiled scripts to be stored in the cache. 0 means no cache, -1 - unbounded cache. The default value is 100.
• script.cache.expire - allows to specify the length of time after a compiled script is last accessed that it should be automatically removed. The default value is no expiration.