Query intermittent failure Index scan timed out

membase.api.exception.CBQError: CBQError: host 172.23.120.76: ERROR:{'requestID': 'bdcb9526-bee8-4a8b-966b-210e82fb560a', 'signature': {'airportname': 'json'}, 'results': [], 'errors': [{'code': 5000, 'msg': ' Index scan timed out from [127.0.0.1:9101] - cause:  Index scan timed out from [127.0.0.1:9101]'}], 'status': 'errors', 'metrics': {'elapsedTime': '4m0.023010778s', 'executionTime': '4m0.02295263s', 'resultCount': 0, 'resultSize': 0, 'serviceLoad': 1, 'errorCount': 1}} 

[2020-12-07 10:07:33,429] - [tuq:2435] INFO - SUCCESS: User(s) Joao Downing created

[2020-12-07 10:07:33,440] - [tuq:1406] INFO - RUN QUERY GRANT admin to joaoDoe

[2020-12-07 10:07:33,440] - [rest_client:3810] INFO - query params : statement=GRANT+admin+to+joaoDoe&scan_consistency=REQUEST_PLUS

[2020-12-07 10:07:33,488] - [tuq:1454] INFO - TOTAL ELAPSED TIME: 46.264685ms

[2020-12-07 10:07:33,517] - [tuq:1406] INFO - RUN QUERY SELECT ADVISOR({'action':'start', 'duration':'40m', 'profile': 'joaoDoe', 'query_count':5, 'response':'50ms'})

[2020-12-07 10:07:33,517] - [rest_client:3810] INFO - query params : statement=SELECT+ADVISOR%28%7B%27action%27%3A%27start%27%2C+%27duration%27%3A%2740m%27%2C+%27profile%27%3A+%27joaoDoe%27%2C+%27query_count%27%3A5%2C+%27response%27%3A%2750ms%27%7D%29&scan_consistency=REQUEST_PLUS

[2020-12-07 10:07:33,535] - [tuq:1454] INFO - TOTAL ELAPSED TIME: 15.936595ms

[2020-12-07 10:07:33,553] - [tuq:1406] INFO - RUN QUERY SELECT airportname FROM `travel-sample` WHERE type = "airport" AND lower(city) = "lyon" AND country = "France"

[2020-12-07 10:07:33,553] - [rest_client:3810] INFO - query params : statement=SELECT+airportname+FROM+%60travel-sample%60+WHERE+type+%3D+%22airport%22+AND+lower%28city%29+%3D+%22lyon%22+AND+country+%3D+%22France%22&scan_consistency=REQUEST_PLUS

[2020-12-07 10:11:33,578] - [rest_client:1003] ERROR - POST http://172.23.120.76:8093/query?statement=SELECT+airportname+FROM+%60travel-sample%60+WHERE+type+%3D+%22airport%22+AND+lower%28city%29+%3D+%22lyon%22+AND+country+%3D+%22France%22&scan_consistency=REQUEST_PLUS body:  headers: {'Authorization': 'Basic am9hb0RvZTpwYXNzd29yZDE='} error: 500 reason: unknown b'{\n"requestID": "bdcb9526-bee8-4a8b-966b-210e82fb560a",\n"signature": {"airportname":"json"},\n"results": [\n],\n"errors": [{"code":5000,"msg":" Index scan timed out from [127.0.0.1:9101] - cause:  Index scan timed out from [127.0.0.1:9101]"}],\n"status": "errors",\n"metrics": {"elapsedTime": "4m0.023010778s","executionTime": "4m0.02295263s","resultCount": 0,"resultSize": 0,"serviceLoad": 1,"errorCount": 1}\n}\n' auth: joaoDoe:password1

[2020-12-07 10:11:33,579] - [tuq_advisor:527] ERROR - Advisor session failed: CBQError: host 172.23.120.76: ERROR:{'requestID': 'bdcb9526-bee8-4a8b-966b-210e82fb560a', 'signature': {'airportname': 'json'}, 'results': [], 'errors': [{'code': 5000, 'msg': ' Index scan timed out from [127.0.0.1:9101] - cause:  Index scan timed out from [127.0.0.1:9101]'}], 'status': 'errors', 'metrics': {'elapsedTime': '4m0.023010778s', 'executionTime': '4m0.02295263s', 'resultCount': 0, 'resultSize': 0, 'serviceLoad': 1, 'errorCount': 1}}