masterha_master_monitor: 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 Debian possible default full paths are:

/usr/bin/masterha_master_monitor - from package: mha4mysql-manager

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

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