categraf/inputs/mysql/processlist.go

package mysql

import (
	"database/sql"
	"log"
	"strings"

	"flashcat.cloud/categraf/inputs"
	"flashcat.cloud/categraf/pkg/tagx"
	"github.com/toolkits/pkg/container/list"
)

// These are const but can't be declared as such because golang doesn't allow const maps
var (
	// status counter
	generalThreadStates = map[string]uint32{
		"after create":              uint32(0),
		"altering table":            uint32(0),
		"analyzing":                 uint32(0),
		"checking permissions":      uint32(0),
		"checking table":            uint32(0),
		"cleaning up":               uint32(0),
		"closing tables":            uint32(0),
		"converting heap to myisam": uint32(0),
		"copying to tmp table":      uint32(0),
		"creating sort index":       uint32(0),
		"creating table":            uint32(0),
		"creating tmp table":        uint32(0),
		"deleting":                  uint32(0),
		"executing":                 uint32(0),
		"execution of init_command": uint32(0),
		"end":                       uint32(0),
		"freeing items":             uint32(0),
		"flushing tables":           uint32(0),
		"fulltext initialization":   uint32(0),
		"idle":                      uint32(0),
		"init":                      uint32(0),
		"killed":                    uint32(0),
		"waiting for lock":          uint32(0),
		"logging slow query":        uint32(0),
		"login":                     uint32(0),
		"manage keys":               uint32(0),
		"opening tables":            uint32(0),
		"optimizing":                uint32(0),
		"preparing":                 uint32(0),
		"reading from net":          uint32(0),
		"removing duplicates":       uint32(0),
		"removing tmp table":        uint32(0),
		"reopen tables":             uint32(0),
		"repair by sorting":         uint32(0),
		"repair done":               uint32(0),
		"repair with keycache":      uint32(0),
		"replication master":        uint32(0),
		"rolling back":              uint32(0),
		"searching rows for update": uint32(0),
		"sending data":              uint32(0),
		"sorting for group":         uint32(0),
		"sorting for order":         uint32(0),
		"sorting index":             uint32(0),
		"sorting result":            uint32(0),
		"statistics":                uint32(0),
		"updating":                  uint32(0),
		"waiting for tables":        uint32(0),
		"waiting for table flush":   uint32(0),
		"waiting on cond":           uint32(0),
		"writing to net":            uint32(0),
		"other":                     uint32(0),
	}
	// plaintext statuses
	stateStatusMappings = map[string]string{
		"user sleep":     "idle",
		"creating index": "altering table",
		"committing alter table to storage engine": "altering table",
		"discard or import tablespace":             "altering table",
		"rename":                                   "altering table",
		"setup":                                    "altering table",
		"renaming result table":                    "altering table",
		"preparing for alter table":                "altering table",
		"copying to group table":                   "copying to tmp table",
		"copy to tmp table":                        "copying to tmp table",
		"query end":                                "end",
		"update":                                   "updating",
		"updating main table":                      "updating",
		"updating reference tables":                "updating",
		"system lock":                              "waiting for lock",
		"user lock":                                "waiting for lock",
		"table lock":                               "waiting for lock",
		"deleting from main table":                 "deleting",
		"deleting from reference tables":           "deleting",
	}
)

func (m *MySQL) gatherProcesslistByState(slist *list.SafeList, ins *Instance, db *sql.DB, globalTags map[string]string) {
	if !ins.GatherProcessListProcessByState {
		return
	}

	rows, err := db.Query(SQL_INFO_SCHEMA_PROCESSLIST)
	if err != nil {
		log.Println("E! failed to get processlist:", err)
		return
	}

	defer rows.Close()

	labels := tagx.Copy(globalTags)

	// mapping of state with its counts
	stateCounts := make(map[string]uint32, len(generalThreadStates))
	// set map with keys and default values
	for k, v := range generalThreadStates {
		stateCounts[k] = v
	}

	for rows.Next() {
		var (
			command string
			state   string
			count   uint32
		)

		err = rows.Scan(&command, &state, &count)
		if err != nil {
			log.Println("W! failed to scan rows:", err)
			return
		}
		// each state has its mapping
		foundState := findThreadState(command, state)
		// count each state
		stateCounts[foundState] += count
	}

	for s, c := range stateCounts {
		slist.PushFront(inputs.NewSample("processlist_processes_by_state", c, labels, map[string]string{"state": s}))
	}
}

// findThreadState can be used to find thread state by command and plain state
func findThreadState(rawCommand, rawState string) string {
	var (
		// replace '_' symbol with space
		command = strings.Replace(strings.ToLower(rawCommand), "_", " ", -1)
		state   = strings.Replace(strings.ToLower(rawState), "_", " ", -1)
	)
	// if the state is already valid, then return it
	if _, ok := generalThreadStates[state]; ok {
		return state
	}

	// if state is plain, return the mapping
	if mappedState, ok := stateStatusMappings[state]; ok {
		return mappedState
	}
	// if the state is any lock, return the special state
	if strings.Contains(state, "waiting for") && strings.Contains(state, "lock") {
		return "waiting for lock"
	}

	if command == "sleep" && state == "" {
		return "idle"
	}

	if command == "query" {
		return "executing"
	}

	if command == "binlog dump" {
		return "replication master"
	}
	// if no mappings found and state is invalid, then return "other" state
	return "other"
}