node_cpu：系统CPU使用量
node_disk*：磁盘IO
node_filesystem*：文件系统用量
node_load1：系统负载
node_memeory*：内存使用量
node_network*：网络带宽
node_time：当前系统时间
go_*：node exporter中go相关指标
process_*：node exporter自身进程相关运行指标
* node_cpu -> node_cpu_seconds_total
* node_memory_MemTotal -> node_memory_MemTotal_bytes
* node_memory_MemFree -> node_memory_MemFree_bytes
* node_filesystem_avail -> node_filesystem_avail_bytes
* node_filesystem_size -> node_filesystem_size_bytes
* node_disk_io_time_ms -> node_disk_io_time_seconds_total
* node_disk_reads_completed -> node_disk_reads_completed_total
* node_disk_sectors_written -> node_disk_written_bytes_total
* node_time -> node_time_seconds
* node_boot_time -> node_boot_time_seconds
* node_intr -> node_intr_total
