Add log comment for prom remote read queries

storage/clickhouse/clickhouse.go

@@ -18,6 +18,7 @@ package clickhouse
 import (
 	"context"
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"net/url"
 	"os"
@@ -165,7 +166,8 @@ func (ch *clickHouse) runTimeSeriesReloader(ctx context.Context) {
 		err := func() error {
 			query := fmt.Sprintf(queryTmpl, ch.database, distributedTimeSeriesV4)
 			ch.l.Debug("Running reloader query:", query)
-			rows, err := ch.db.Query(query, ch.lastLoadedTimeStamp)
+			ctx = ch.addClickHouseSettings(ctx)
+			rows, err := ch.db.QueryContext(ctx, query, ch.lastLoadedTimeStamp)
 			if err != nil {
 				return err
 			}
@@ -218,6 +220,51 @@ func (ch *clickHouse) runTimeSeriesReloader(ctx context.Context) {
 	}
 }
 
+func (ch *clickHouse) getLogComment(ctx context.Context) string {
+	// Get the key-value pairs from context for log comment
+	kv := ctx.Value("log_comment")
+	if kv == nil {
+		return ""
+	}
+
+	logCommentKVs, ok := kv.(map[string]string)
+	if !ok {
+		return ""
+	}
+
+	logComment, _ := json.Marshal(logCommentKVs)
+
+	return string(logComment)
+}
+
+func (ch *clickHouse) addClickHouseSettings(ctx context.Context) context.Context {
+	settings := clickhouse.Settings{}
+
+	logComment := ch.getLogComment(ctx)
+	if logComment != "" {
+		settings["log_comment"] = logComment
+	}
+
+	if os.Getenv("ClickHouseMaxExecutionTime") != "" {
+		settings["max_execution_time"] = os.Getenv("ClickHouseMaxExecutionTime")
+	}
+
+	if os.Getenv("ClickHouseMaxExecutionTimeLeaf") != "" {
+		settings["max_execution_time_leaf"] = os.Getenv("ClickHouseMaxExecutionTimeLeaf")
+	}
+
+	if os.Getenv("ClickHouseTimeoutBeforeCheckingExecutionSpeed") != "" {
+		settings["timeout_before_checking_execution_speed"] = os.Getenv("ClickHouseTimeoutBeforeCheckingExecutionSpeed")
+	}
+
+	if os.Getenv("ClickHouseMaxBytesToRead") != "" {
+		settings["max_bytes_to_read"] = os.Getenv("ClickHouseMaxBytesToRead")
+	}
+
+	ctx = clickhouse.Context(ctx, clickhouse.WithSettings(settings))
+	return ctx
+}
+
 func (ch *clickHouse) scanSamples(rows *sql.Rows, fingerprints map[uint64][]prompb.Label) ([]*prompb.TimeSeries, error) {
 	// scan results
 	var res []*prompb.TimeSeries
@@ -285,7 +332,7 @@ func (ch *clickHouse) querySamples(
 	query := fmt.Sprintf(`
 		SELECT metric_name, fingerprint, unix_milli, value
 			FROM %s.%s
-			WHERE metric_name = $1 AND fingerprint GLOBAL IN (%s) AND unix_milli >= $%s AND unix_milli <= $%s;`,
+			WHERE metric_name = $1 AND fingerprint GLOBAL IN (%s) AND unix_milli >= $%s AND unix_milli <= $%s ORDER BY fingerprint, unix_milli;`,
 		ch.database, distributedSamplesV4, subQuery, strconv.Itoa(argCount+2), strconv.Itoa(argCount+3))
 	query = strings.TrimSpace(query)
 
@@ -295,6 +342,7 @@ func (ch *clickHouse) querySamples(
 	allArgs = append(allArgs, start, end)
 
 	// run query
+	ctx = ch.addClickHouseSettings(ctx)
 	rows, err := ch.db.QueryContext(ctx, query, allArgs...)
 	if err != nil {
 		return nil, errors.WithStack(err)
@@ -383,6 +431,7 @@ func (ch *clickHouse) prepareClickHouseQuery(query *prompb.Query, metricName str
 
 func (ch *clickHouse) fingerprintsForQuery(ctx context.Context, query string, args []interface{}) (map[uint64][]prompb.Label, error) {
 	// run query
+	ctx = ch.addClickHouseSettings(ctx)
 	rows, err := ch.db.QueryContext(ctx, query, args...)
 	if err != nil {
 		return nil, err