From: Simon J Mudd Date: Mon, 1 Dec 2014 19:33:54 +0000 (+0100) Subject: Provide more useful error message if MySQL version is not expected X-Git-Url: http://git.iain.cx/?a=commitdiff_plain;h=fee828471a2ac86d4cc8f4982d444a9d4a9a0344;p=pstop.git Provide more useful error message if MySQL version is not expected --- diff --git a/main.go b/main.go index 708a77a..4825729 100644 --- a/main.go +++ b/main.go @@ -4,11 +4,13 @@ package main import ( "database/sql" + "errors" "flag" "fmt" "log" "os" "os/signal" + "regexp" "runtime/pprof" "syscall" "time" @@ -27,14 +29,19 @@ const ( db = "performance_schema" ) -var flag_version = flag.Bool("version", false, "Show the version of "+lib.MyName()) -var flag_debug = flag.Bool("debug", false, "Enabling debug logging") -var flag_help = flag.Bool("help", false, "Provide some help for "+lib.MyName()) -var cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file") +var ( + flag_version = flag.Bool("version", false, "Show the version of "+lib.MyName()) + flag_debug = flag.Bool("debug", false, "Enabling debug logging") + flag_help = flag.Bool("help", false, "Provide some help for "+lib.MyName()) + cpuprofile = flag.String("cpuprofile", "", "write cpu profile to file") + + re_valid_version = regexp.MustCompile(`^(5\.[67]\.|10\.[01])`) +) func get_db_handle() *sql.DB { var err error var dbh *sql.DB + lib.Logger.Println("get_db_handle() connecting to database") dbh, err = mysql_defaults_file.OpenUsingDefaultsFile(sql_driver, "", "performance_schema") if err != nil { @@ -72,6 +79,24 @@ func usage() { fmt.Println("-version show the version") } +// pstop requires MySQL 5.6+ or MariaDB 10.0+. Check the version +// rather than giving an error message if the requires P_S tables can't +// be found. +func validate_mysql_version(dbh *sql.DB) error { + lib.Logger.Println("validate_mysql_version()") + + _, mysql_version := lib.SelectGlobalVariableByVariableName(dbh, "VERSION") + + lib.Logger.Println("- mysql_version: '" + mysql_version + "'") + if !re_valid_version.MatchString(mysql_version) { + err := errors.New(lib.MyName() + " does not work with MySQL version " + mysql_version) + return err + } + lib.Logger.Println("- MySQL version is valid, continuing") + + return nil +} + func main() { flag.Parse() @@ -98,8 +123,13 @@ func main() { } lib.Logger.Println("Starting " + lib.MyName()) - var state state.State + dbh := get_db_handle() + if err := validate_mysql_version(dbh); err != nil { + log.Fatal(err) + } + + var state state.State interval := time.Second sigChan := make(chan os.Signal, 1) done := make(chan struct{}) @@ -110,7 +140,7 @@ func main() { ticker := time.NewTicker(interval) // generate a periodic signal - state.Setup(get_db_handle()) + state.Setup(dbh) finished := false for !finished {