Grafana :
{“search_type”:“count”,“ignore_unavailable”:true,“index”:“graylog*”}
{“size”:0,“query”:{“bool”:{“filter”:[{“range”:{“timestamp”:{“gte”:“1500557461375”,“lte”:“1500557761375”,“format”:“epoch_millis”}}},{“query_string”:{“analyze_wildcard”:true,“query”:"“myrouter” AND (“990-D” OR “991-D” OR “default-D”)"}}]}},“aggs”:{“2”:{“date_histogram”:{“interval”:“2s”,“field”:“timestamp”,“min_doc_count”:0,“extended_bounds”:{“min”:“1500557461375”,“max”:“1500557761375”},“format”:“epoch_millis”},“aggs”:{}}}}
Looks like the Graylog query returns unaggregated data. The Grafana query has a date histogram aggregation and groups in 2s intervals. Have you tried setting the Group by time interval field to be >5m (either in the data source settings or on the metrics tab of your panel)?
Also, the from and to timestamps are different so you are not comparing the same five minutes.