Elasticsearch1.4.4 always oom,we suspected nested object

Ees1.4.4 appear oom 。According to the dump,we found a big object ,so we suspected that the nested object caused this phenomenon. I hope that you can tell me how to avoid this problem and we idea is true or not ,thanks.66stances of "org.elasticsearch.index.cache.fixedbitset.FixedBitSetFilterCache",loaded by "sun.misc.Launcher$AppClassLoader@0x7f8b7d3d20f8" occupy 17,351,214,92(54.14%) byte.<nabble_img src="215.jpg" border="0" class="left"/><nabble_img src="216.jpg" border="0" class="left"/>