在GCE上监控postgresql的堆栈驱动程序问题

Question

我在Google Compute Engine (ubuntu)上安装了Stackdriver，并尝试将其配置为监视安装在该实例中的postgresql服务。

日志显示它能够连接到数据库，但在尝试获取统计数据时失败。

这是我执行命令"service stackdriver-agent status“时的结果。

有没有想到我错过了什么？

service stackdriver-agent status
● stackdriver-agent.service - LSB: start and stop Stackdriver Agent
   Loaded: loaded (/etc/init.d/stackdriver-agent)
   Active: active (running) since Tue 2017-06-13 17:41:15 UTC; 14min ago
  Process: 5024 ExecStop=/etc/init.d/stackdriver-agent stop (code=exited, status=0/SUCCESS)
  Process: 5045 ExecStart=/etc/init.d/stackdriver-agent start (code=exited, status=0/SUCCESS)
   CGroup: /system.slice/stackdriver-agent.service
           └─5067 /opt/stackdriver/collectd/sbin/stackdriver-collectd -C /opt/stackdriver/collectd/etc/collectd.conf -P /var/run/stackdriver-agent.pid

Jun 13 17:55:15 prod-postgres collectd[5067]: parse_value: Failed to parse string as derive: .
Jun 13 17:55:15 prod-postgres collectd[5067]: db query utils: udb_result_submit: Parsing `' as derive failed.
Jun 13 17:55:15 prod-postgres collectd[5067]: db query utils: udb_query_handle_result (postgres, queries): All results failed.
Jun 13 17:55:15 prod-postgres collectd[5067]: postgresql: udb_query_handle_result failed with status -1.
Jun 13 17:55:15 prod-postgres collectd[5067]: parse_value: Failed to parse string as gauge: .
Jun 13 17:55:15 prod-postgres collectd[5067]: db query utils: udb_result_submit: Parsing `' as gauge failed.
Jun 13 17:55:15 prod-postgres collectd[5067]: parse_value: Failed to parse string as gauge: .
Jun 13 17:55:15 prod-postgres collectd[5067]: db query utils: udb_result_submit: Parsing `' as gauge failed.
Jun 13 17:55:15 prod-postgres collectd[5067]: db query utils: udb_query_handle_result (postgres, table_states): All results failed.
Jun 13 17:55:15 prod-postgres collectd[5067]: postgresql: udb_query_handle_result failed with status -1.