youtubebeat/vendor/github.com/elastic/beats/metricbeat/module/mysql/galera_status/status.go

113 lines
3.1 KiB
Go

// Licensed to Elasticsearch B.V. under one or more contributor
// license agreements. See the NOTICE file distributed with
// this work for additional information regarding copyright
// ownership. Elasticsearch B.V. licenses this file to you under
// the Apache License, Version 2.0 (the "License"); you may
// not use this file except in compliance with the License.
// You may obtain a copy of the License at
//
// http://www.apache.org/licenses/LICENSE-2.0
//
// Unless required by applicable law or agreed to in writing,
// software distributed under the License is distributed on an
// "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
// KIND, either express or implied. See the License for the
// specific language governing permissions and limitations
// under the License.
/*
Package galera_status fetches MySQL Galera server status metrics.
For more information on the query it uses, see:
http://dev.mysql.com/doc/refman/5.7/en/show-status.html
http://galeracluster.com/documentation-webpages/galerastatusvariables.html
*/
package galera_status
import (
"database/sql"
"github.com/elastic/beats/libbeat/common"
"github.com/elastic/beats/libbeat/common/cfgwarn"
"github.com/elastic/beats/libbeat/logp"
"github.com/elastic/beats/metricbeat/mb"
"github.com/elastic/beats/metricbeat/module/mysql"
"github.com/pkg/errors"
)
var (
debugf = logp.MakeDebug("mysql-galera-status")
)
// init registers the MetricSet with the central registry.
func init() {
mb.Registry.MustAddMetricSet("mysql", "galera_status", New,
mb.WithHostParser(mysql.ParseDSN),
)
}
// MetricSet for fetching Galera-MySQL server status
type MetricSet struct {
mb.BaseMetricSet
db *sql.DB
}
// New create a new instance of the MetricSet
// Loads query_mode config setting from the config file
func New(base mb.BaseMetricSet) (mb.MetricSet, error) {
cfgwarn.Experimental("The mysql galera_status metricset is experimental")
return &MetricSet{BaseMetricSet: base}, nil
}
// Fetch methods implements the data gathering and data conversion to the right format
// It returns the event which is then forward to the output.
func (m *MetricSet) Fetch() (common.MapStr, error) {
if m.db == nil {
var err error
m.db, err = mysql.NewDB(m.HostData().URI)
if err != nil {
return nil, errors.Wrap(err, "Galera-status fetch failed")
}
}
status, err := m.loadStatus(m.db)
if err != nil {
return nil, err
}
event := eventMapping(status)
if m.Module().Config().Raw {
event["raw"] = rawEventMapping(status)
}
return event, nil
}
// loadStatus loads all status entries from the given database into an array.
func (m *MetricSet) loadStatus(db *sql.DB) (map[string]string, error) {
// Returns the global status, also for versions previous 5.0.2
rows, err := db.Query("SHOW /*!50002 GLOBAL */ STATUS LIKE 'wsrep_%';")
if err != nil {
return nil, err
}
defer rows.Close()
galeraStatus := map[string]string{}
for rows.Next() {
var name string
var value string
err = rows.Scan(&name, &value)
if err != nil {
return nil, err
}
galeraStatus[name] = value
}
return galeraStatus, nil
}