Morelike this Query eats up memory - elasticsearch

Question

I have 3 nodes 2 masters with data and 1 is master=false and data=false used for facets,aggregation.
All nodes are having 30gb ram with 16gb allocated to elastic search and remaining OS
I have some 600 indices with 5 shards each storing content of documents with vector=true.
Now when I execute a simple more like this query,first 2 nodes starts eating up memory resulting into out of memory exception.Am i missing any settings? or is this a bug?
This is the error log
[2015-06-12 04:19:35,729][DEBUG][action.search.type ] [Master1] [113] Failed to execute fetch phase
org.elasticsearch.ElasticsearchException: Java heap space
at org.elasticsearch.ExceptionsHelper.convertToRuntime(ExceptionsHelper.java:44)
at org.elasticsearch.search.SearchService.executeFetchPhase(SearchService.java:513)
at org.elasticsearch.search.action.SearchServiceTransportAction$17.call(SearchServi ceTransportAction.java:452)
at org.elasticsearch.search.action.SearchServiceTransportAction$17.call(SearchServi ceTransportAction.java:449)
at org.elasticsearch.search.action.SearchServiceTransportAction$23.run(SearchServic eTransportAction.java:559)
at java.util.concurrent.ThreadPoolExecutor.runWorker(Unknown Source)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(Unknown Source)
at java.lang.Thread.run(Unknown Source)
Caused by: java.lang.OutOfMemoryError: Java heap space
at java.util.Arrays.copyOfRange(Unknown Source)
at java.lang.String.(Unknown Source)
at java.lang.StringBuilder.toString(Unknown Source)
at org.elasticsearch.common.jackson.core.util.TextBuffer.contentsAsString(TextBuffe r.java:349)
at org.elasticsearch.common.jackson.core.json.UTF8StreamJsonParser.getText(UTF8StreamJsonParser.java:281)
at org.elasticsearch.common.xcontent.json.JsonXContentParser.text(JsonXContentParser.java:86)
at org.elasticsearch.common.xcontent.support.AbstractXContentParser.readValue(AbstractXContentParser.java:293)
at org.elasticsearch.common.xcontent.support.AbstractXContentParser.readMap(AbstractXContentParser.java:275)
at org.elasticsearch.common.xcontent.support.AbstractXContentParser.readMap(AbstractXContentParser.java:254)
at org.elasticsearch.common.xcontent.support.AbstractXContentParser.map(AbstractXContentParser.java:208)
at org.elasticsearch.common.xcontent.support.AbstractXContentParser.mapAndClose(AbstractXContentParser.java:219)
at org.elasticsearch.common.xcontent.XContentHelper.convertToMap(XContentHelper.java:125)
at org.elasticsearch.common.xcontent.XContentHelper.convertToMap(XContentHelper.java:79)
at org.elasticsearch.search.lookup.SourceLookup.sourceAsMapAndType(SourceLookup.java:87)
at org.elasticsearch.search.lookup.SourceLookup.loadSourceIfNeeded(SourceLookup.java:63)
at org.elasticsearch.search.lookup.SourceLookup.extractRawValues(SourceLookup.java:145)
at org.elasticsearch.search.fetch.FetchPhase.createSearchHit(FetchPhase.java:245)
at org.elasticsearch.search.fetch.FetchPhase.execute(FetchPhase.java:182)
at org.elasticsearch.search.SearchService.executeFetchPhase(SearchService.java:501)
This is my master node statistics
{
"timestamp": 1435219276968,
"cluster_name": "cluster1",
"status": "green",
"indices": {
"count": 537,
"shards": {
"total": 5314,
"primaries": 2657,
"replication": 1,
"index": {
"shards": {
"min": 2,
"max": 10,
"avg": 9.895716945996275
},
"primaries": {
"min": 1,
"max": 5,
"avg": 4.947858472998138
},
"replication": {
"min": 1,
"max": 1,
"avg": 1
}
}
},
"docs": {
"count": 60900916,
"deleted": 50541
},
"store": {
"size": "1tb",
"size_in_bytes": 1192366468003,
"throttle_time": "6.2m",
"throttle_time_in_millis": 372988
},
"fielddata": {
"memory_size": "0b",
"memory_size_in_bytes": 0,
"evictions": 11175
},
"filter_cache": {
"memory_size": "1.6mb",
"memory_size_in_bytes": 1705012,
"evictions": 0
},
"id_cache": {
"memory_size": "0b",
"memory_size_in_bytes": 0
},
"completion": {
"size": "0b",
"size_in_bytes": 0
},
"segments": {
"count": 36771,
"memory": "3gb",
"memory_in_bytes": 3236984326,
"index_writer_memory": "0b",
"index_writer_memory_in_bytes": 0,
"index_writer_max_memory": "2.5gb",
"index_writer_max_memory_in_bytes": 2720768000,
"version_map_memory": "0b",
"version_map_memory_in_bytes": 0,
"fixed_bit_set": "0b",
"fixed_bit_set_memory_in_bytes": 0
},
"percolate": {
"total": 0,
"get_time": "0s",
"time_in_millis": 0,
"current": 0,
"memory_size_in_bytes": -1,
"memory_size": "-1b",
"queries": 0
}
},
"nodes": {
"count": {
"total": 3,
"master_only": 0,
"data_only": 0,
"master_data": 2,
"client": 0
},
"versions": [
"1.5.2"
],
"os": {
"available_processors": 24,
"mem": {
"total": "95.9gb",
"total_in_bytes": 103077617664
},
"cpu": [
{
"vendor": "Intel",
"model": "Xeon",
"mhz": 2400,
"total_cores": 8,
"total_sockets": 2,
"cores_per_socket": 4,
"cache_size": "-1b",
"cache_size_in_bytes": -1,
"count": 3
}
]
},
"process": {
"cpu": {
"percent": 17
},
"open_file_descriptors": {
"min": 1361,
"max": 57055,
"avg": 38465
}
},
"jvm": {
"max_uptime": "2.9d",
"max_uptime_in_millis": 251100991,
"versions": [
{
"version": "1.8.0_45",
"vm_name": "Java HotSpot(TM) 64-Bit Server VM",
"vm_version": "25.45-b02",
"vm_vendor": "Oracle Corporation",
"count": 3
}
],
"mem": {
"heap_used": "18.2gb",
"heap_used_in_bytes": 19577530528,
"heap_max": "47.8gb",
"heap_max_in_bytes": 51330416640
},
"threads": 325
},
"fs": {},
"plugins": []
}
}
EDIT:
{
"size": 100,
"fields": [
"docid"
],
"explain": false,
"query": {
"more_like_this": {
"fields": [
"content"
],
"ids": [
"AU2h82DxWiT16vBNxqGo"
],
"min_term_freq": 1,
"min_doc_freq": 1,
"include": "true",
"max_query_terms": 1000,
"boost_terms": 1
}
}
}