lucene_snapshot: Investigate Rally SO_Vector IOOBE failure

[ChrisHegarty]

so-vector failed with

	Cannot run task [knn-search-10-50-acceptedAnswerId]: Request returned an error. Error type: api, Description: 
{"error":{"root_cause":[{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 
11992"},{"type":"index_out_of_bounds_exception","reason":"Range [2, 2 + 65534) out of bounds for length 
12818"}],"type":"search_phase_execution_exception","reason":"all shards 
failed","phase":"dfs","grouped":true,"failed_shards":[{"shard":0,"index":"vectors","node":"t0-
dJEPpSmGE9Qsc9vqGog","reason":{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of 
bounds for length 11992","suppressed":[{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of 
bounds for length 22472"},{"type":"index_out_of_bounds_exception","reason":"Range [393216, 393216 + 65536) out of 
bounds for length 411854"},{"type":"index_out_of_bounds_exception","reason":"Range [2, 2 + 65534) out of bounds for 
length 27083"},{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 
38600"}]}},{"shard":1,"index":"vectors","node":"t0-dJEPpSmGE9Qsc9vqGog","reason":
{"type":"index_out_of_bounds_exception","reason":"Range [2, 2 + 65534) out of bounds for length 12818"}}],"caused_by":
{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 11992","caused_by":
{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 11992","suppressed":
[{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 22472"},
{"type":"index_out_of_bounds_exception","reason":"Range [393216, 393216 + 65536) out of bounds for length 411854"},
{"type":"index_out_of_bounds_exception","reason":"Range [2, 2 + 65534) out of bounds for length 27083"},
{"type":"index_out_of_bounds_exception","reason":"Range [0, 0 + 65536) out of bounds for length 
38600"}]}}},"status":500}, HTTP Status: 500

[elasticsearchmachine]

Pinging @elastic/es-search-relevance (Team:Search Relevance)

[ChrisHegarty]

https://buildkite.com/elastic/elasticsearch-performance-esbench-nightly/builds/912/summary/annotations?sid=01971891-cbec-4c1e-9d86-6f847a74142c