Improve logging of problems during db connection

go/db/db.go

@@ -21,6 +21,7 @@ import (
 	"errors"
 	"fmt"
 	"regexp"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -100,7 +101,8 @@ func openTopology(host string, port int, readTimeout int) (db *sql.DB, err error
 			return nil, err
 		}
 	}
-	if db, _, err = sqlutils.GetDB(mysql_uri); err != nil {
+	sqlUtilsLogger := SqlUtilsLogger{client_context: host + ":" + strconv.Itoa(port)}
+	if db, _, err = sqlutils.GetDB(mysql_uri, sqlUtilsLogger); err != nil {
 		return nil, err
 	}
 	if config.Config.MySQLConnectionLifetimeSeconds > 0 {
@@ -123,7 +125,8 @@ func openOrchestratorMySQLGeneric() (db *sql.DB, fromCache bool, err error) {
 	if config.Config.MySQLOrchestratorUseMutualTLS {
 		uri, _ = SetupMySQLOrchestratorTLS(uri)
 	}
-	return sqlutils.GetDB(uri)
+	sqlUtilsLogger := SqlUtilsLogger{client_context: config.Config.MySQLOrchestratorHost + ":" + config.Config.MySQLOrchestratorHost}
+	return sqlutils.GetDB(uri, sqlUtilsLogger)
 }
 
 func IsSQLite() bool {
@@ -174,7 +177,7 @@ func safeMySQLURI(dsn string) string {
 func OpenOrchestrator() (db *sql.DB, err error) {
 	var fromCache bool
 	if IsSQLite() {
-		db, fromCache, err = sqlutils.GetSQLiteDB(config.Config.SQLite3DataFile)
+		db, fromCache, err = sqlutils.GetSQLiteDB(config.Config.SQLite3DataFile, nil)
 		if err == nil && !fromCache {
 			log.Debugf("Connected to orchestrator backend: sqlite on %v", config.Config.SQLite3DataFile)
 		}
@@ -191,7 +194,8 @@ func OpenOrchestrator() (db *sql.DB, err error) {
 			}
 		}
 		dsn := getMySQLURI()
-		db, fromCache, err = sqlutils.GetDB(dsn)
+		sqlUtilsLogger := SqlUtilsLogger{client_context: dsn}
+		db, fromCache, err = sqlutils.GetDB(dsn, sqlUtilsLogger)
 		if err == nil && !fromCache {
 			log.Debugf("Connected to orchestrator backend: %v", safeMySQLURI(dsn))
 

go/db/tls.go

@@ -19,6 +19,7 @@ package db
 import (
 	"crypto/tls"
 	"fmt"
+	"strconv"
 	"strings"
 	"time"
 
@@ -55,6 +56,23 @@ func init() {
 	metrics.Register("instance_tls.write_cache", writeInstanceTLSCacheCounter)
 }
 
+type SqlUtilsLogger struct {
+	client_context string
+}
+
+func (logger SqlUtilsLogger) OnError(caller_context string, query string, err error) error {
+	query = strings.Join(strings.Fields(query), " ")  // trim whitespaces
+	query = strings.Replace(query, "%", "%%", -1)  // escape %
+
+	msg := fmt.Sprintf("%+v(%+v) %+v: %+v",
+						caller_context,
+						logger.client_context,
+						query,
+						err)
+
+	return log.Errorf(msg)
+}
+
 func requiresTLS(host string, port int, mysql_uri string) bool {
 	cacheKey := fmt.Sprintf("%s:%d", host, port)
 
@@ -64,7 +82,8 @@ func requiresTLS(host string, port int, mysql_uri string) bool {
 	}
 
 	required := false
-	db, _, _ := sqlutils.GetDB(mysql_uri)
+	sqlUtilsLogger := SqlUtilsLogger{client_context: host + ":" + strconv.Itoa(port)}
+	db, _, _ := sqlutils.GetDB(mysql_uri, sqlUtilsLogger)
 	if err := db.Ping(); err != nil && (strings.Contains(err.Error(), Error3159) || strings.Contains(err.Error(), Error1045)) {
 		required = true
 	}

go/raft/rel_store.go

@@ -75,7 +75,7 @@ func (relStore *RelationalStore) openDB() (*sql.DB, error) {
 
 	if relStore.backend == nil {
 		relStoreFile := filepath.Join(relStore.dataDir, raftStoreFile)
-		sqliteDB, _, err := sqlutils.GetSQLiteDB(relStoreFile)
+		sqliteDB, _, err := sqlutils.GetSQLiteDB(relStoreFile, nil)
 		if err != nil {
 			return nil, err
 		}