mysqldumpslow: command not found

Maybe Your $PATH variable doesn't contain the default paths? echo $PATH should give something like:

[root@server ~]# echo $PATH
/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin

If it's empty, You may set the PATH variable with this command

export PATH="/usr/local/sbin:/usr/local/bin:/sbin:/bin:/usr/sbin:/usr/bin:/root/bin"

On CentOS possible default full paths are:

/usr/bin/mysqldumpslow - from package: mysql55w-server
/usr/bin/mysqldumpslow - from package: mysql-server

You may install the required package with command yum install {package}

On Debian possible default full paths are:

/usr/bin/mysqldumpslow - from package: mariadb-client-10.0
/usr/bin/mysqldumpslow - from package: mysql-client-5.5

You may install the required package with command apt-get install {package}

Error in other languages:
mysqldumpslow: bevel nie gevind nie
mysqldumpslow: comandă negăsită
mysqldumpslow: comando não encontrado
mysqldumpslow: commande introuvable
mysqldumpslow: command not found
mysqldumpslow: käsku ei ole
mysqldumpslow: không tìm thấy lệnh
mysqldumpslow: komanda nerasta
mysqldumpslow: Kommando nicht gefunden.
mysqldumpslow: kommandot finns inte
mysqldumpslow: komut yok
mysqldumpslow: nie znaleziono polecenia
mysqldumpslow: níor aimsíodh an t-ordú
mysqldumpslow: no se encontró la orden
mysqldumpslow: no s'ha trobat l'ordre
mysqldumpslow: opdracht niet gevonden
mysqldumpslow: parancs nem található
mysqldumpslow: perintah tidak ditemukan
mysqldumpslow: príkaz nenájdený
mysqldumpslow: příkaz nenalezen
mysqldumpslow: команда не найдена
mysqldumpslow: командата не е открита
mysqldumpslow: 命令找不到
mysqldumpslow: コマンドが見つかりません