How to fix the following error?
Visualize: Request to Elasticsearch failed: {"error":{"root_cause":[],"type":"search_phase_execution_exception","reason":"","phase":"fetch","grouped":true,"failed_shards":[],"caused_by":{"type":"es_rejected_execution_exception","reason":"rejected execution of org.elasticsearch.action.search.FetchSearchPhase$1@601f098c on EsThreadPoolExecutor[search, queue capacity = 1000, org.elasticsearch.common.util.concurrent.EsThreadPoolExecutor@1a6a27b5[Running, pool size = 4, active threads = 4, queued tasks = 1000, completed tasks = 117814]]"}},"status":503}