It is perfectly normal for Elsticsearch to make use of all memory on a server. First you have the heap, which has a set size. make sure this is a bit smaller than 32GB so you use compressed pointers. This should be shown in the logs on startup. Apart from this Elasticsearch also uses memory in addition to the heap. Part of this is due to off-heap storage, but the largest amount is usually used by the operating system page cache to cache files that are modfied or used. The memory used by the page cache helps Elasticsearch improve performance by reducing disk I/O, but it is worth noting that this memory at any time can be released by the operating system if there is another process that need it. Having Elasticsearch use 100% of the server memory should therefore not be a problem. The memory is there to be used.