collectd后台监控程序

[toc]

简介

collectd 是一个后台监控程序，用来采集其所运行系统上的系统信息，并提供各种存储方式来存储为不同值的格式，例如 RRD 文件形式、文本格式、MongoDB 等等

连接：官网文档、下载地址、源码地址

优点

C语言编写，性能好，跨平台能力强
插件丰富，方便扩充

缺点

监控简单
不能直接生成图形

使用

配置

修改sudo vim /opt/collectd/etc/collectd.conf选择自己需要的插件

启动

systemctl start collectd 启动服务

查看数据

若开启了rrdtool插件就可在/var/lib/collectd/rrd/目录下看到相应的统计数据

日志存储在/var/log/syslog

主要插件

virt

vcpu

static int get_vcpu_stats(virDomainPtr domain, unsigned short nr_virt_cpu) {
  int max_cpus = VIR_NODEINFO_MAXCPUS(nodeinfo);

  virVcpuInfoPtr vinfo = calloc(nr_virt_cpu, sizeof(*vinfo));
  if (vinfo == NULL) {
    ERROR(PLUGIN_NAME " plugin: calloc failed.");
    return -1;
  }

  int cpu_map_len = 0;
  unsigned char *cpumaps = NULL;
  if (extra_stats & ex_stats_vcpupin) {
    cpu_map_len = VIR_CPU_MAPLEN(max_cpus);
    cpumaps = calloc(nr_virt_cpu, cpu_map_len);

    if (cpumaps == NULL) {
      ERROR(PLUGIN_NAME " plugin: calloc failed.");
      sfree(vinfo);
      return -1;
    }
  }

  int status =
      virDomainGetVcpus(domain, vinfo, nr_virt_cpu, cpumaps, cpu_map_len);
  if (status < 0) {
    ERROR(PLUGIN_NAME " plugin: virDomainGetVcpus failed with status %i.",
          status);

    virErrorPtr err = virGetLastError();
    if (err->code == VIR_ERR_NO_SUPPORT) {
      if (extra_stats & ex_stats_vcpu)
        ERROR(PLUGIN_NAME
              " plugin: Disabled unsupported ExtraStats selector: vcpu");
      if (extra_stats & ex_stats_vcpupin)
        ERROR(PLUGIN_NAME
              " plugin: Disabled unsupported ExtraStats selector: vcpupin");
      extra_stats &= ~(ex_stats_vcpu | ex_stats_vcpupin);
    }

    sfree(cpumaps);
    sfree(vinfo);
    return -1;
  }

  for (int i = 0; i < nr_virt_cpu; ++i) {
    if (extra_stats & ex_stats_vcpu)
      vcpu_submit(vinfo[i].cpuTime, domain, vinfo[i].number, "virt_vcpu");
    if (extra_stats & ex_stats_vcpupin)
      vcpu_pin_submit(domain, max_cpus, i, cpumaps, cpu_map_len);
  }

  sfree(cpumaps);
  sfree(vinfo);
  return 0;
}

static void vcpu_submit(derive_t value, virDomainPtr dom, int vcpu_nr,
                        const char *type) {
  char type_instance[DATA_MAX_NAME_LEN];

  ssnprintf(type_instance, sizeof(type_instance), "%d", vcpu_nr);
  submit(dom, type, type_instance, &(value_t){.derive = value}, 1);
}

static void submit(virDomainPtr dom, char const *type,
                   char const *type_instance, value_t *values,
                   size_t values_len) {
  value_list_t vl = VALUE_LIST_INIT;
  init_value_list(&vl, dom);

  vl.values = values;
  vl.values_len = values_len;

  sstrncpy(vl.type, type, sizeof(vl.type));
  if (type_instance != NULL)
    sstrncpy(vl.type_instance, type_instance, sizeof(vl.type_instance));

  plugin_dispatch_values(&vl);
}