Add minimal MySQL version to Scraper interface (#328)

* Add Version method to Scraper interface.
* Skip scrapers for unsupported MySQL versions.

Signed-off-by: Alexey Palazhchenko <alexey.palazhchenko@percona.com>

collector/binlog.go

@@ -64,6 +64,11 @@ func (ScrapeBinlogSize) Help() string {
 	return "Collect the current size of all registered binlog files"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeBinlogSize) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeBinlogSize) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var logBin uint8
@@ -113,3 +118,6 @@ func (ScrapeBinlogSize) Scrape(ctx context.Context, db *sql.DB, ch chan<- promet
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeBinlogSize{}

collector/engine_innodb.go

@@ -45,6 +45,11 @@ func (ScrapeEngineInnodbStatus) Help() string {
 	return "Collect from SHOW ENGINE INNODB STATUS"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeEngineInnodbStatus) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeEngineInnodbStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	rows, err := db.QueryContext(ctx, engineInnodbStatusQuery)
@@ -92,3 +97,6 @@ func (ScrapeEngineInnodbStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeEngineInnodbStatus{}

collector/engine_tokudb.go

@@ -43,6 +43,11 @@ func (ScrapeEngineTokudbStatus) Help() string {
 	return "Collect from SHOW ENGINE TOKUDB STATUS"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeEngineTokudbStatus) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeEngineTokudbStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	tokudbRows, err := db.QueryContext(ctx, engineTokudbStatusQuery)
@@ -87,3 +92,6 @@ func sanitizeTokudbMetric(metricName string) string {
 	}
 	return metricName
 }
+
+// check interface
+var _ Scraper = ScrapeEngineTokudbStatus{}

collector/exporter.go

@@ -17,6 +17,8 @@ import (
 	"context"
 	"database/sql"
 	"fmt"
+	"regexp"
+	"strconv"
 	"strings"
 	"sync"
 	"time"
@@ -33,14 +35,20 @@ const (
 	exporter = "exporter"
 )
 
-// SQL Queries.
+// SQL queries and parameters.
 const (
+	versionQuery = `SELECT @@version`
+
 	// System variable params formatting.
 	// See: https://github.com/go-sql-driver/mysql#system-variables
 	sessionSettingsParam = `log_slow_filter=%27tmp_table_on_disk,filesort_on_disk%27`
 	timeoutParam         = `lock_wait_timeout=%d`
 )
 
+var (
+	versionRE = regexp.MustCompile(`^\d+\.\d+`)
+)
+
 // Tunable flags.
 var (
 	exporterLockTimeout = kingpin.Flag(
@@ -145,9 +153,14 @@ func (e *Exporter) scrape(ctx context.Context, ch chan<- prometheus.Metric) {
 
 	ch <- prometheus.MustNewConstMetric(scrapeDurationDesc, prometheus.GaugeValue, time.Since(scrapeTime).Seconds(), "connection")
 
-	wg := &sync.WaitGroup{}
+	version := getMySQLVersion(db)
+	var wg sync.WaitGroup
 	defer wg.Wait()
 	for _, scraper := range e.scrapers {
+		if version < scraper.Version() {
+			continue
+		}
+
 		wg.Add(1)
 		go func(scraper Scraper) {
 			defer wg.Done()
@@ -163,6 +176,19 @@ func (e *Exporter) scrape(ctx context.Context, ch chan<- prometheus.Metric) {
 	}
 }
 
+func getMySQLVersion(db *sql.DB) float64 {
+	var versionStr string
+	var versionNum float64
+	if err := db.QueryRow(versionQuery).Scan(&versionStr); err == nil {
+		versionNum, _ = strconv.ParseFloat(versionRE.FindString(versionStr), 64)
+	}
+	// If we can't match/parse the version, set it some big value that matches all versions.
+	if versionNum == 0 {
+		versionNum = 999
+	}
+	return versionNum
+}
+
 // Metrics represents exporter metrics which values can be carried between http requests.
 type Metrics struct {
 	TotalScrapes prometheus.Counter

collector/exporter_test.go

@@ -15,6 +15,7 @@ package collector
 
 import (
 	"context"
+	"database/sql"
 	"testing"
 
 	"github.com/prometheus/client_golang/prometheus"
@@ -63,3 +64,17 @@ func TestExporter(t *testing.T) {
 		}
 	})
 }
+
+func TestGetMySQLVersion(t *testing.T) {
+	if testing.Short() {
+		t.Skip("-short is passed, skipping test")
+	}
+
+	convey.Convey("Version parsing", t, func() {
+		db, err := sql.Open("mysql", dsn)
+		convey.So(err, convey.ShouldBeNil)
+		defer db.Close()
+
+		convey.So(getMySQLVersion(db), convey.ShouldBeBetweenOrEqual, 5.5, 10.3)
+	})
+}

collector/global_status.go

@@ -87,6 +87,11 @@ func (ScrapeGlobalStatus) Help() string {
 	return "Collect from SHOW GLOBAL STATUS"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeGlobalStatus) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeGlobalStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	globalStatusRows, err := db.QueryContext(ctx, globalStatusQuery)
@@ -207,3 +212,6 @@ func (ScrapeGlobalStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prom
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeGlobalStatus{}

collector/global_variables.go

@@ -131,6 +131,11 @@ func (ScrapeGlobalVariables) Help() string {
 	return "Collect from SHOW GLOBAL VARIABLES"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeGlobalVariables) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeGlobalVariables) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	globalVariablesRows, err := db.QueryContext(ctx, globalVariablesQuery)
@@ -227,3 +232,6 @@ func validPrometheusName(s string) string {
 	s = strings.ToLower(s)
 	return s
 }
+
+// check interface
+var _ Scraper = ScrapeGlobalVariables{}

collector/heartbeat.go

@@ -79,6 +79,11 @@ func (ScrapeHeartbeat) Help() string {
 	return "Collect from heartbeat"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeHeartbeat) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeHeartbeat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	query := fmt.Sprintf(heartbeatQuery, *collectHeartbeatDatabase, *collectHeartbeatTable)
@@ -126,3 +131,6 @@ func (ScrapeHeartbeat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometh
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeHeartbeat{}

collector/info_schema_auto_increment.go

@@ -63,6 +63,11 @@ func (ScrapeAutoIncrementColumns) Help() string {
 	return "Collect auto_increment columns and max values from information_schema"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeAutoIncrementColumns) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeAutoIncrementColumns) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	autoIncrementRows, err := db.QueryContext(ctx, infoSchemaAutoIncrementQuery)
@@ -93,3 +98,6 @@ func (ScrapeAutoIncrementColumns) Scrape(ctx context.Context, db *sql.DB, ch cha
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeAutoIncrementColumns{}

collector/info_schema_clientstats.go

@@ -154,6 +154,11 @@ func (ScrapeClientStat) Help() string {
 	return "If running with userstat=1, set to true to collect client statistics"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeClientStat) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeClientStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var varName, varVal string
@@ -213,3 +218,6 @@ func (ScrapeClientStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- promet
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeClientStat{}

collector/info_schema_innodb_cmp.go

@@ -70,6 +70,11 @@ func (ScrapeInnodbCmp) Help() string {
 	return "Collect metrics from information_schema.innodb_cmp"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeInnodbCmp) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeInnodbCmp) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	informationSchemaInnodbCmpRows, err := db.QueryContext(ctx, innodbCmpQuery)
@@ -84,7 +89,6 @@ func (ScrapeInnodbCmp) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometh
 	)
 
 	for informationSchemaInnodbCmpRows.Next() {
-
 		if err := informationSchemaInnodbCmpRows.Scan(
 			&page_size, &compress_ops, &compress_ops_ok, &compress_time, &uncompress_ops, &uncompress_time,
 		); err != nil {
@@ -96,8 +100,10 @@ func (ScrapeInnodbCmp) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometh
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpCompressTime, prometheus.CounterValue, compress_time, page_size)
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpUncompressOps, prometheus.CounterValue, uncompress_ops, page_size)
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpUncompressTime, prometheus.CounterValue, uncompress_time, page_size)
-
 	}
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeInnodbCmp{}

collector/info_schema_innodb_cmpmem.go

@@ -65,6 +65,11 @@ func (ScrapeInnodbCmpMem) Help() string {
 	return "Collect metrics from information_schema.innodb_cmpmem"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeInnodbCmpMem) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeInnodbCmpMem) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	informationSchemaInnodbCmpMemRows, err := db.QueryContext(ctx, innodbCmpMemQuery)
@@ -89,7 +94,9 @@ func (ScrapeInnodbCmpMem) Scrape(ctx context.Context, db *sql.DB, ch chan<- prom
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpMemPagesFree, prometheus.CounterValue, pages_free, page_size, buffer_pool)
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpMemRelocationOps, prometheus.CounterValue, relocation_ops, page_size, buffer_pool)
 		ch <- prometheus.MustNewConstMetric(infoSchemaInnodbCmpMemRelocationTime, prometheus.CounterValue, (relocation_time / 1000), page_size, buffer_pool)
-
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeInnodbCmpMem{}

collector/info_schema_innodb_metrics.go

@@ -75,6 +75,11 @@ func (ScrapeInnodbMetrics) Help() string {
 	return "Collect metrics from information_schema.innodb_metrics"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeInnodbMetrics) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeInnodbMetrics) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	innodbMetricsRows, err := db.QueryContext(ctx, infoSchemaInnodbMetricsQuery)
@@ -164,3 +169,6 @@ func (ScrapeInnodbMetrics) Scrape(ctx context.Context, db *sql.DB, ch chan<- pro
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeInnodbMetrics{}

collector/info_schema_innodb_sys_tablespaces.go

@@ -66,6 +66,11 @@ func (ScrapeInfoSchemaInnodbTablespaces) Help() string {
 	return "Collect metrics from information_schema.innodb_sys_tablespaces"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeInfoSchemaInnodbTablespaces) Version() float64 {
+	return 5.7
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeInfoSchemaInnodbTablespaces) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	tablespacesRows, err := db.QueryContext(ctx, innodbTablespacesQuery)
@@ -113,3 +118,6 @@ func (ScrapeInfoSchemaInnodbTablespaces) Scrape(ctx context.Context, db *sql.DB,
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeInfoSchemaInnodbTablespaces{}

collector/info_schema_processlist.go

@@ -170,6 +170,11 @@ func (ScrapeProcesslist) Help() string {
 	return "Collect current thread state counts from the information_schema.processlist"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeProcesslist) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeProcesslist) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	processQuery := fmt.Sprintf(
@@ -261,3 +266,6 @@ func deriveThreadState(command string, state string) string {
 	}
 	return "other"
 }
+
+// check interface
+var _ Scraper = ScrapeProcesslist{}

collector/info_schema_query_response_time.go

@@ -112,6 +112,11 @@ func (ScrapeQueryResponseTime) Help() string {
 	return "Collect query response time distribution if query_response_time_stats is ON."
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeQueryResponseTime) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeQueryResponseTime) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var queryStats uint8
@@ -135,3 +140,6 @@ func (ScrapeQueryResponseTime) Scrape(ctx context.Context, db *sql.DB, ch chan<-
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeQueryResponseTime{}

collector/info_schema_tables.go

@@ -90,6 +90,11 @@ func (ScrapeTableSchema) Help() string {
 	return "Collect metrics from information_schema.tables"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeTableSchema) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeTableSchema) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var dbList []string
@@ -177,3 +182,6 @@ func (ScrapeTableSchema) Scrape(ctx context.Context, db *sql.DB, ch chan<- prome
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeTableSchema{}

collector/info_schema_tablestats.go

@@ -65,6 +65,11 @@ func (ScrapeTableStat) Help() string {
 	return "If running with userstat=1, set to true to collect table statistics"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeTableStat) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeTableStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var varName, varVal string
@@ -118,3 +123,6 @@ func (ScrapeTableStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometh
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeTableStat{}

collector/info_schema_userstats.go

@@ -150,6 +150,11 @@ func (ScrapeUserStat) Help() string {
 	return "If running with userstat=1, set to true to collect user statistics"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeUserStat) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeUserStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var varName, varVal string
@@ -208,3 +213,6 @@ func (ScrapeUserStat) Scrape(ctx context.Context, db *sql.DB, ch chan<- promethe
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeUserStat{}

collector/perf_schema_events_statements.go

@@ -161,6 +161,11 @@ func (ScrapePerfEventsStatements) Help() string {
 	return "Collect metrics from performance_schema.events_statements_summary_by_digest"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfEventsStatements) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfEventsStatements) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	perfQuery := fmt.Sprintf(
@@ -241,3 +246,6 @@ func (ScrapePerfEventsStatements) Scrape(ctx context.Context, db *sql.DB, ch cha
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfEventsStatements{}

collector/perf_schema_events_waits.go

@@ -54,6 +54,11 @@ func (ScrapePerfEventsWaits) Help() string {
 	return "Collect metrics from performance_schema.events_waits_summary_global_by_event_name"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfEventsWaits) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfEventsWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	// Timers here are returned in picoseconds.
@@ -85,3 +90,6 @@ func (ScrapePerfEventsWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<- p
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfEventsWaits{}

collector/perf_schema_file_events.go

@@ -63,6 +63,11 @@ func (ScrapePerfFileEvents) Help() string {
 	return "Collect metrics from performance_schema.file_summary_by_event_name"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfFileEvents) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfFileEvents) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	// Timers here are returned in picoseconds.
@@ -122,3 +127,6 @@ func (ScrapePerfFileEvents) Scrape(ctx context.Context, db *sql.DB, ch chan<- pr
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfFileEvents{}

collector/perf_schema_file_instances.go

@@ -73,6 +73,11 @@ func (ScrapePerfFileInstances) Help() string {
 	return "Collect metrics from performance_schema.file_summary_by_instance"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfFileInstances) Version() float64 {
+	return 5.5
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfFileInstances) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	// Timers here are returned in picoseconds.
@@ -118,3 +123,6 @@ func (ScrapePerfFileInstances) Scrape(ctx context.Context, db *sql.DB, ch chan<-
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfFileInstances{}

collector/perf_schema_index_io_waits.go

@@ -57,6 +57,11 @@ func (ScrapePerfIndexIOWaits) Help() string {
 	return "Collect metrics from performance_schema.table_io_waits_summary_by_index_usage"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfIndexIOWaits) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfIndexIOWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	perfSchemaIndexWaitsRows, err := db.QueryContext(ctx, perfIndexIOWaitsQuery)
@@ -120,3 +125,6 @@ func (ScrapePerfIndexIOWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<-
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfIndexIOWaits{}

collector/perf_schema_replication_group_member_stats.go

@@ -63,6 +63,11 @@ func (ScrapePerfReplicationGroupMemberStats) Help() string {
 	return "Collect metrics from performance_schema.replication_group_member_stats"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfReplicationGroupMemberStats) Version() float64 {
+	return 5.7
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfReplicationGroupMemberStats) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	perfReplicationGroupMemeberStatsRows, err := db.QueryContext(ctx, perfReplicationGroupMemeberStatsQuery)
@@ -103,3 +108,6 @@ func (ScrapePerfReplicationGroupMemberStats) Scrape(ctx context.Context, db *sql
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfReplicationGroupMemberStats{}

collector/perf_schema_table_io_waits.go

@@ -58,6 +58,11 @@ func (ScrapePerfTableIOWaits) Help() string {
 	return "Collect metrics from performance_schema.table_io_waits_summary_by_table"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfTableIOWaits) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfTableIOWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	perfSchemaTableWaitsRows, err := db.QueryContext(ctx, perfTableIOWaitsQuery)
@@ -114,3 +119,6 @@ func (ScrapePerfTableIOWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<-
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfTableIOWaits{}

collector/perf_schema_table_lock_waits.go

@@ -87,6 +87,11 @@ func (ScrapePerfTableLockWaits) Help() string {
 	return "Collect metrics from performance_schema.table_lock_waits_summary_by_table"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapePerfTableLockWaits) Version() float64 {
+	return 5.6
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapePerfTableLockWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	perfSchemaTableLockWaitsRows, err := db.QueryContext(ctx, perfTableLockWaitsQuery)
@@ -230,3 +235,6 @@ func (ScrapePerfTableLockWaits) Scrape(ctx context.Context, db *sql.DB, ch chan<
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapePerfTableLockWaits{}

collector/scraper.go

@@ -25,9 +25,14 @@ import (
 type Scraper interface {
 	// Name of the Scraper. Should be unique.
 	Name() string
+
 	// Help describes the role of the Scraper.
 	// Example: "Collect from SHOW ENGINE INNODB STATUS"
 	Help() string
+
+	// Version of MySQL from which scraper is available.
+	Version() float64
+
 	// Scrape collects data from database connection and sends it over channel as prometheus metric.
 	Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error
 }

collector/slave_hosts.go

@@ -55,6 +55,11 @@ func (ScrapeSlaveHosts) Help() string {
 	return "Scrape information from 'SHOW SLAVE HOSTS'"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeSlaveHosts) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeSlaveHosts) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	slaveHostsRows, err := db.QueryContext(ctx, slaveHostsQuery)
@@ -110,3 +115,6 @@ func (ScrapeSlaveHosts) Scrape(ctx context.Context, db *sql.DB, ch chan<- promet
 
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeSlaveHosts{}

collector/slave_status.go

@@ -62,6 +62,11 @@ func (ScrapeSlaveStatus) Help() string {
 	return "Collect from SHOW SLAVE STATUS"
 }
 
+// Version of MySQL from which scraper is available.
+func (ScrapeSlaveStatus) Version() float64 {
+	return 5.1
+}
+
 // Scrape collects data from database connection and sends it over channel as prometheus metric.
 func (ScrapeSlaveStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prometheus.Metric) error {
 	var (
@@ -129,3 +134,6 @@ func (ScrapeSlaveStatus) Scrape(ctx context.Context, db *sql.DB, ch chan<- prome
 	}
 	return nil
 }
+
+// check interface
+var _ Scraper = ScrapeSlaveStatus{}