Expose the concurrent query count key in sdk (#875)

* Expose the concurrent query count key in sdk

* Update backend/config.go

Co-authored-by: Andres Martinez Gotor <[email protected]>

---------

Co-authored-by: Andres Martinez Gotor <[email protected]>

Author: itsmylife

backend/config.go

@@ -12,7 +12,8 @@ import (
 )
 
 const (
-	AppURL = "GF_APP_URL"
+	AppURL               = "GF_APP_URL"
+	ConcurrentQueryCount = "GF_CONCURRENT_QUERY_COUNT"
 )
 
 type configKey struct{}
@@ -138,6 +139,18 @@ func (c *GrafanaCfg) AppURL() (string, error) {
 	return url, nil
 }
 
+func (c *GrafanaCfg) ConcurrentQueryCount() (int, error) {
+	count, ok := c.config[ConcurrentQueryCount]
+	if !ok {
+		return 0, fmt.Errorf("ConcurrentQueryCount not set in config")
+	}
+	i, err := strconv.Atoi(count)
+	if err != nil {
+		return 0, fmt.Errorf("ConcurrentQueryCount cannot be converted to integer")
+	}
+	return i, nil
+}
+
 type userAgentKey struct{}
 
 // UserAgentFromContext returns user agent from context.