Eu tenho um servidor Munin com vários nós Munin, todos configurados usando o Ansible, então a configuração é praticamente a mesma. Os sistemas são o Debian Jessie.
Os gráficos mysql_ * de dois dos servidores estão presentes, mas vazios, enquanto os outros três servidores possuem gráficos completos.
A execução de munin-run --debug mysql_commands em um dos servidores defeituosos retorna a saída correta:
# munin-run --debug mysql_commands
# Processing plugin configuration from /etc/munin/plugin-conf.d/ansible.conf
# Processing plugin configuration from /etc/munin/plugin-conf.d/munin-node
# Setting /rgid/ruid/ to /119/0/
# Setting /egid/euid/ to /119 119/0/
# Setting up environment
# Environment mysqluser = debian-sys-maint
# Environment mysqlconnection = DBI:mysql:mysql;mysql_read_default_file=/etc/mysql/debian.cnf
# Environment mysqlopts = --defaults-file=/etc/mysql/debian.cnf
# About to run '/etc/munin/plugins/mysql_commands'
Com_delete.value 4546376
Com_insert.value 2804559
Com_insert_select.value 341479
Com_load.value 0
Com_replace.value 0
Com_replace_select.value 0
Com_select.value 236967004
Com_update.value 7069348
Com_update_multi.value 0
Então parece que o nó Munin está funcionando bem.
Mas quando executo munin-cron no servidor munin, o plug-in retorna bad exit quando buscado:
# sudo -u munin munin-cron --host server.com --debug
...
2018/01/09 08:35:01 [DEBUG] for my mysql_commands (irqstats mysql_innodb_tnx diskstats apache_accesses smart_sda df ntp_offset vmstat fw_packets mysql_select_types netstat users mysql_qcache mysql_table_locks swap mysql_slow mysql_myisam_indexes if_err_eth0 apt hddtemp_smartctl ntp_kernel_err ntp_kernel_pll_freq mysql_innodb_rows mysql_innodb_bpool forks ntp_kernel_pll_off cpu load postfix_mailvolume postfix_mailqueue mysql_qcache_mem open_inodes processes http_loadtime open_files uptime mysql_commands mysql_innodb_semaphores apt_all mysql_innodb_io smart_sdb memory mysql_connections mysql_files_tables mysql_network_traffic df_inode mysql_sorts if_eth0 entropy proc_pri mysql_innodb_bpool_act apache_processes threads mysql_innodb_log mysql_innodb_insert_buf mysql_tmp_tables mysql_innodb_io_pend interrupts apache_volume)
2018/01/09 08:35:01 [DEBUG] Fetching service configuration for 'mysql_commands'
2018/01/09 08:35:01 [DEBUG] Writing to socket: "config mysql_commands
".
2018/01/09 08:35:02 [DEBUG] Reading from socket: "graph_vlabel Commands per ${graph_period}\ngraph_total Questions\ngraph_args --base 1000\ngraph_title Command Counters\ngraph_category mysql2\nCom_delete.type DERIVE\nCom_delete.label Delete\nCom_delete.draw STACK\nCom_delete.min 0\nCom_insert.draw STACK\nCom_insert.min 0\nCom_insert.type DERIVE\nCom_insert.label Insert\nCom_insert_select.type DERIVE\nCom_insert_select.label Insert select\nCom_insert_select.draw STACK\nCom_insert_select.min 0\nCom_load.label Load Data\nCom_load.type DERIVE\nCom_load.min 0\nCom_load.draw STACK\nCom_replace.type DERIVE\nCom_replace.label Replace\nCom_replace.draw STACK\nCom_replace.min 0\nCom_replace_select.draw STACK\nCom_replace_select.min 0\nCom_replace_select.type DERIVE\nCom_replace_select.label Replace select\nCom_select.type DERIVE\nCom_select.label Select\nCom_select.draw STACK\nCom_select.min 0\nCom_update.type DERIVE\nCom_update.label Update\nCom_update.draw STACK\nCom_update.min 0\nCom_update_multi.label Update multi\nCom_update_multi.type DERIVE\nCom_update_multi.min 0\nCom_update_multi.draw STACK".
2018/01/09 08:35:02 [DEBUG] config: 0.151266 sec for 'mysql_commands' on server.com/1.2.3.4/4949
2018/01/09 08:35:02 [DEBUG] Now parsing config output from plugin mysql_commands on server.com
2018/01/09 08:35:02 [DEBUG] update_rate 0 for mysql_commands on server.com/1.2.3.4:4949
2018/01/09 08:35:02 [DEBUG] No service data for mysql_commands, fetching it
2018/01/09 08:35:02 [DEBUG] Writing to socket: "fetch mysql_commands
".
2018/01/09 08:35:02 [DEBUG] data: 0.175058 sec for 'mysql_commands' on server.com/1.2.3.4/4949
2018/01/09 08:35:02 [DEBUG] Now parsing fetch output from plugin mysql_commands on server.com/1.2.3.4:4949
2018/01/09 08:35:02 [FETCH from mysql_commands] # Bad exit
...
Isso acontece com todos os plug-ins mysql_ * em dois servidores, mas eles funcionam bem em outros três servidores. Outro plugin do Munin funciona bem em todos os servidores, então a configuração geral parece ok.
Configuração para plugins mysql_ *:
[mysql*]
user root
env.mysqlopts --defaults-file=/etc/mysql/debian.cnf
env.mysqluser debian-sys-maint
env.mysqlconnection DBI:mysql:mysql;mysql_read_default_file=/etc/mysql/debian.cnf
Nenhuma entrada nova é adicionada ao log do nó Munin ( /var/log/munin/munin-node.log ) nem ao MySQL quando sudo -u munin munin-cron é executado.
O serviço do nó Munin reporta a operação normal:
# systemctl status munin-node
● munin-node.service - Munin Node
Loaded: loaded (/lib/systemd/system/munin-node.service; enabled)
Active: active (running) since mié 2018-01-17 14:20:10 CET; 19s ago
Docs: man:munin-node(1)
http://munin.readthedocs.org/en/stable-2.0/reference/munin-node.html
Process: 4515 ExecStart=/usr/sbin/munin-node $DAEMON_ARGS (code=exited, status=0/SUCCESS)
Main PID: 4541 (munin-node)
CGroup: /system.slice/munin-node.service
└─4541 /usr/bin/perl -wT /usr/sbin/munin-node
ene 17 14:20:10 example.com systemd[1]: Started Munin Node.
O que pode estar errado com esses nós? Ou como posso depurar o problema?