1 // Manage the configuration of setup_instruments.
2 package setup_instruments
9 "github.com/sjmudd/pstop/lib"
12 // We only match on the error number
13 // Error 1142: UPDATE command denied to user 'cacti'@'10.164.132.182' for table 'setup_instruments'
14 // Error 1290: The MySQL server is running with the --read-only option so it cannot execute this statement
15 var EXPECTED_UPDATE_ERRORS = []string{
20 // one row of performance_schema.setup_instruments
21 type table_row struct {
27 type table_rows []table_row
29 // SetupInstruments "object"
30 type SetupInstruments struct {
37 // Return a newly initialised SetupInstruments structure with a handle to the database.
38 // Better to return a pointer ?
39 func NewSetupInstruments(dbh *sql.DB) SetupInstruments {
40 return SetupInstruments{dbh: dbh}
43 // enable mutex and stage monitoring
44 func (si *SetupInstruments) EnableMonitoring() {
45 si.EnableMutexMonitoring()
46 si.EnableStageMonitoring()
49 // Change settings to monitor stage/sql/%
50 func (si *SetupInstruments) EnableStageMonitoring() {
51 lib.Logger.Println("EnableStageMonitoring")
52 sql := "SELECT NAME, ENABLED, TIMED FROM setup_instruments WHERE NAME LIKE 'stage/sql/%' AND ( enabled <> 'YES' OR timed <> 'YES' )"
53 collecting := "Collecting setup_instruments stage/sql configuration settings"
54 updating := "Updating setup_instruments configuration for: stage/sql"
56 si.Configure(sql, collecting, updating)
57 lib.Logger.Println("EnableStageMonitoring finishes")
60 // Change settings to monitor wait/synch/mutex/%
61 func (si *SetupInstruments) EnableMutexMonitoring() {
62 lib.Logger.Println("EnableMutexMonitoring")
63 sql := "SELECT NAME, ENABLED, TIMED FROM setup_instruments WHERE NAME LIKE 'wait/synch/mutex/%' AND ( enabled <> 'YES' OR timed <> 'YES' )"
64 collecting := "Collecting setup_instruments wait/synch/mutex configuration settings"
65 updating := "Updating setup_instruments configuration for: wait/synch/mutex"
67 si.Configure(sql, collecting, updating)
68 lib.Logger.Println("EnableMutexMonitoring finishes")
71 // return true if the error is not in the expected list
72 func error_in_expected_list(actual_error string, expected_errors []string) bool {
73 lib.Logger.Println("checking if", actual_error, "is in", expected_errors)
74 e := actual_error[0:11]
75 expected_error := false
76 for i := range expected_errors {
77 if e == expected_errors[i] {
78 lib.Logger.Println("found an expected error", expected_errors[i])
83 lib.Logger.Println("returning", expected_error)
87 // generic routine (now) to update some rows in setup instruments
88 func (si *SetupInstruments) Configure(select_sql string, collecting, updating string) {
89 lib.Logger.Println(fmt.Sprintf("Configure(%q,%q,%q)", select_sql, collecting, updating))
90 // skip if we've tried and failed
91 if si.update_tried && !si.update_succeeded {
92 lib.Logger.Println("Configure() - Skipping further configuration")
96 // setup the old values in case they're not set
98 si.rows = make([]table_row, 0, 500)
101 lib.Logger.Println(collecting)
103 lib.Logger.Println("dbh.query", select_sql)
104 rows, err := si.dbh.Query(select_sql)
115 &r.TIMED); err != nil {
118 si.rows = append(si.rows, r)
121 if err := rows.Err(); err != nil {
125 lib.Logger.Println("- found", count, "rows whose configuration need changing")
127 // update the rows which need to be set - do multiple updates but I don't care
128 lib.Logger.Println(updating)
130 const update_sql = "UPDATE setup_instruments SET enabled = ?, TIMED = ? WHERE NAME = ?"
131 lib.Logger.Println("Preparing statement:", update_sql)
132 si.update_tried = true
133 lib.Logger.Println("dbh.Prepare", update_sql)
134 stmt, err := si.dbh.Prepare(update_sql)
136 lib.Logger.Println("- prepare gave error:", err.Error())
137 if !error_in_expected_list(err.Error(), EXPECTED_UPDATE_ERRORS) {
138 log.Fatal("Not expected error so giving up")
140 lib.Logger.Println("- expected error so not running statement")
143 lib.Logger.Println("Prepare succeeded, trying to update", len(si.rows), "row(s)")
145 for i := range si.rows {
146 lib.Logger.Println("- changing row:", si.rows[i].NAME)
147 lib.Logger.Println("stmt.Exec", "YES", "YES", si.rows[i].NAME)
148 if res, err := stmt.Exec("YES", "YES", si.rows[i].NAME); err == nil {
149 lib.Logger.Println("update succeeded")
150 si.update_succeeded = true
151 c, _ := res.RowsAffected()
154 si.update_succeeded = false
155 if error_in_expected_list(err.Error(), EXPECTED_UPDATE_ERRORS) {
156 lib.Logger.Println("Insufficient privileges to UPDATE setup_instruments: " + err.Error())
157 lib.Logger.Println("Not attempting further updates")
164 if si.update_succeeded {
165 lib.Logger.Println(count, "rows changed in p_s.setup_instruments")
169 lib.Logger.Println("Configure() returns update_tried", si.update_tried, ", update_succeeded", si.update_succeeded)
172 // restore setup_instruments rows to their previous settings
173 func (si *SetupInstruments) RestoreConfiguration() {
174 lib.Logger.Println("RestoreConfiguration()")
175 // If the previous update didn't work then don't try to restore
176 if !si.update_succeeded {
177 lib.Logger.Println("Not restoring p_s.setup_instruments to original settings as initial configuration attempt failed")
180 lib.Logger.Println("Restoring p_s.setup_instruments to its original settings")
183 // update the rows which need to be set - do multiple updates but I don't care
184 update_sql := "UPDATE setup_instruments SET enabled = ?, TIMED = ? WHERE NAME = ?"
185 lib.Logger.Println("dbh.Prepare(", update_sql, ")")
186 stmt, err := si.dbh.Prepare(update_sql)
191 for i := range si.rows {
192 lib.Logger.Println("stmt.Exec(", si.rows[i].ENABLED, si.rows[i].TIMED, si.rows[i].NAME, ")")
193 if _, err := stmt.Exec(si.rows[i].ENABLED, si.rows[i].TIMED, si.rows[i].NAME); err != nil {
198 lib.Logger.Println("stmt.Close()")
200 lib.Logger.Println(count, "rows changed in p_s.setup_instruments")