+// Manage the configuration of setup_instruments.
package setup_instruments
import (
"database/sql"
+ "fmt"
"log"
"github.com/sjmudd/pstop/lib"
)
-// Error 1142: UPDATE command denied to user
-const UPDATE_FAILED = "Error 1142"
+// constants
+const sql_select = "SELECT NAME, ENABLED, TIMED FROM setup_instruments WHERE NAME LIKE ? AND 'YES NOT IN (enabled,timed)"
-type setup_instruments_row struct {
+// We only match on the error number
+// Error 1142: UPDATE command denied to user 'cacti'@'10.164.132.182' for table 'setup_instruments'
+// Error 1290: The MySQL server is running with the --read-only option so it cannot execute this statement
+var EXPECTED_UPDATE_ERRORS = []string{
+ "Error 1142:",
+ "Error 1290:",
+}
+
+// one row of performance_schema.setup_instruments
+type table_row struct {
NAME string
ENABLED string
TIMED string
}
+type table_rows []table_row
+
+// SetupInstruments "object"
type SetupInstruments struct {
+ update_tried bool
update_succeeded bool
- rows []setup_instruments_row
+ rows table_rows
+ dbh *sql.DB
+}
+
+// Return a newly initialised SetupInstruments structure with a handle to the database.
+// Better to return a pointer ?
+func NewSetupInstruments(dbh *sql.DB) SetupInstruments {
+ return SetupInstruments{dbh: dbh}
+}
+
+// enable mutex and stage monitoring
+func (si *SetupInstruments) EnableMonitoring() {
+ si.EnableMutexMonitoring()
+ si.EnableStageMonitoring()
+}
+
+// Change settings to monitor stage/sql/%
+func (si *SetupInstruments) EnableStageMonitoring() {
+ lib.Logger.Println("EnableStageMonitoring")
+ sql_match := "stage/sql/%"
+ collecting := "Collecting setup_instruments stage/sql configuration settings"
+ updating := "Updating setup_instruments configuration for: stage/sql"
+
+ si.Configure(sql_match, collecting, updating)
+ lib.Logger.Println("EnableStageMonitoring finishes")
}
// Change settings to monitor wait/synch/mutex/%
-func (si *SetupInstruments) EnableMutexMonitoring(dbh *sql.DB) {
- si.rows = make([]setup_instruments_row, 0, 100)
+func (si *SetupInstruments) EnableMutexMonitoring() {
+ lib.Logger.Println("EnableMutexMonitoring")
+ sql_match := "wait/synch/mutex/%"
+ collecting := "Collecting setup_instruments wait/synch/mutex configuration settings"
+ updating := "Updating setup_instruments configuration for: wait/synch/mutex"
+
+ si.Configure(sql_match, collecting, updating)
+ lib.Logger.Println("EnableMutexMonitoring finishes")
+}
+
+// return true if the error is not in the expected list
+func error_in_expected_list(actual_error string, expected_errors []string) bool {
+ lib.Logger.Println("checking if", actual_error, "is in", expected_errors)
+ e := actual_error[0:11]
+ expected_error := false
+ for i := range expected_errors {
+ if e == expected_errors[i] {
+ lib.Logger.Println("found an expected error", expected_errors[i])
+ expected_error = true
+ break
+ }
+ }
+ lib.Logger.Println("returning", expected_error)
+ return expected_error
+}
+
+// generic routine (now) to update some rows in setup instruments
+func (si *SetupInstruments) Configure(sql_match string, collecting, updating string) {
+ lib.Logger.Println(fmt.Sprintf("Configure(%q,%q,%q)", sql_match, collecting, updating))
+ // skip if we've tried and failed
+ if si.update_tried && !si.update_succeeded {
+ lib.Logger.Println("Configure() - Skipping further configuration")
+ return
+ }
- // populate the rows which are not set
- sql := "SELECT NAME, ENABLED, TIMED FROM setup_instruments WHERE NAME LIKE 'wait/synch/mutex/%' AND ( enabled <> 'YES' OR timed <> 'YES' )"
+ // setup the old values in case they're not set
+ if si.rows == nil {
+ si.rows = make([]table_row, 0, 500)
+ }
- lib.Logger.Println("Collecting p_s.setup_instruments wait/synch/mutex configuration settings")
+ lib.Logger.Println(collecting)
- rows, err := dbh.Query(sql)
+ lib.Logger.Println("dbh.query", sql_select, sql_match)
+ rows, err := si.dbh.Query(sql_select, sql_match)
if err != nil {
log.Fatal(err)
-
-
}
- defer rows.Close()
count := 0
for rows.Next() {
- var r setup_instruments_row
+ var r table_row
if err := rows.Scan(
&r.NAME,
&r.ENABLED,
&r.TIMED); err != nil {
log.Fatal(err)
}
- // we collect all information even if it's mainly empty as we may reference it later
si.rows = append(si.rows, r)
count++
}
if err := rows.Err(); err != nil {
log.Fatal(err)
}
+ rows.Close()
lib.Logger.Println("- found", count, "rows whose configuration need changing")
// update the rows which need to be set - do multiple updates but I don't care
- lib.Logger.Println("Updating p_s.setup_instruments to allow wait/synch/mutex configuration")
+ lib.Logger.Println(updating)
- count = 0
- for i := range si.rows {
- sql := "UPDATE setup_instruments SET enabled = 'YES', TIMED = 'YES' WHERE NAME = '" + si.rows[i].NAME + "'"
- if _, err := dbh.Exec(sql); err == nil {
- si.update_succeeded = true
+ const update_sql = "UPDATE setup_instruments SET enabled = ?, TIMED = ? WHERE NAME = ?"
+ lib.Logger.Println("Preparing statement:", update_sql)
+ si.update_tried = true
+ lib.Logger.Println("dbh.Prepare", update_sql)
+ stmt, err := si.dbh.Prepare(update_sql)
+ if err != nil {
+ lib.Logger.Println("- prepare gave error:", err.Error())
+ if !error_in_expected_list(err.Error(), EXPECTED_UPDATE_ERRORS) {
+ log.Fatal("Not expected error so giving up")
} else {
- if err.Error()[0:10] != UPDATE_FAILED {
- log.Fatal(err)
+ lib.Logger.Println("- expected error so not running statement")
+ }
+ } else {
+ lib.Logger.Println("Prepare succeeded, trying to update", len(si.rows), "row(s)")
+ count = 0
+ for i := range si.rows {
+ lib.Logger.Println("- changing row:", si.rows[i].NAME)
+ lib.Logger.Println("stmt.Exec", "YES", "YES", si.rows[i].NAME)
+ if res, err := stmt.Exec("YES", "YES", si.rows[i].NAME); err == nil {
+ lib.Logger.Println("update succeeded")
+ si.update_succeeded = true
+ c, _ := res.RowsAffected()
+ count += int(c)
+ } else {
+ si.update_succeeded = false
+ if error_in_expected_list(err.Error(), EXPECTED_UPDATE_ERRORS) {
+ lib.Logger.Println("Insufficient privileges to UPDATE setup_instruments: " + err.Error())
+ lib.Logger.Println("Not attempting further updates")
+ return
+ } else {
+ log.Fatal(err)
+ }
}
- break
-
}
- count++
+ if si.update_succeeded {
+ lib.Logger.Println(count, "rows changed in p_s.setup_instruments")
+ }
+ stmt.Close()
}
- lib.Logger.Println(count, "rows changed in p_s.setup_instruments")
+ lib.Logger.Println("Configure() returns update_tried", si.update_tried, ", update_succeeded", si.update_succeeded)
}
-// restore any changed rows back to their original state
-func (si *SetupInstruments) Restore(dbh *sql.DB) {
+// Restore setup_instruments rows to their previous settings (if changed previously).
+func (si *SetupInstruments) RestoreConfiguration() {
+ lib.Logger.Println("RestoreConfiguration()")
// If the previous update didn't work then don't try to restore
- if ! si.update_succeeded {
- lib.Logger.Println("Not restoring p_s.setup_instruments to its original settings as previous UPDATE had failed")
+ if !si.update_succeeded {
+ lib.Logger.Println("Not restoring p_s.setup_instruments to original settings as initial configuration attempt failed")
return
} else {
lib.Logger.Println("Restoring p_s.setup_instruments to its original settings")
}
// update the rows which need to be set - do multiple updates but I don't care
+ update_sql := "UPDATE setup_instruments SET enabled = ?, TIMED = ? WHERE NAME = ?"
+ lib.Logger.Println("dbh.Prepare(", update_sql, ")")
+ stmt, err := si.dbh.Prepare(update_sql)
+ if err != nil {
+ log.Fatal(err)
+ }
count := 0
for i := range si.rows {
- sql := "UPDATE setup_instruments SET enabled = '" + si.rows[i].ENABLED + "', TIMED = '" + si.rows[i].TIMED + "' WHERE NAME = '" + si.rows[i].NAME + "'"
- if _, err := dbh.Exec(sql); err != nil {
+ lib.Logger.Println("stmt.Exec(", si.rows[i].ENABLED, si.rows[i].TIMED, si.rows[i].NAME, ")")
+ if _, err := stmt.Exec(si.rows[i].ENABLED, si.rows[i].TIMED, si.rows[i].NAME); err != nil {
log.Fatal(err)
}
count++
}
+ lib.Logger.Println("stmt.Close()")
+ stmt.Close()
lib.Logger.Println(count, "rows changed in p_s.setup_instruments")
}
git://git.iain.cx/iain / pstop.git / blobdiff