在监控设备的时候，在server端的日志中有时候会见到类似another network error, wait for 15s seconds的异常，今天我们看下这个问题的出现原因和解决方案:

问题定位到poller.c，看下下面两份代码:

这个get_values的部分代码:

    for (i = 0; i < num; i++)
    {
        switch (errcodes[i])
        {
            case SUCCEED:
            case NOTSUPPORTED:
            case AGENT_ERROR:
                if (HOST_AVAILABLE_TRUE != last_available)
                {
                    zbx_activate_item_host(&items[i], &timespec);
                    last_available = HOST_AVAILABLE_TRUE;
                }
                break;
            case NETWORK_ERROR:
            case GATEWAY_ERROR:
            case TIMEOUT_ERROR:
                if (HOST_AVAILABLE_FALSE != last_available)
                {
                    zbx_deactivate_item_host(&items[i], &timespec, results[i].msg);
                    last_available = HOST_AVAILABLE_FALSE;
                }
                break;
            case CONFIG_ERROR:
                /* nothing to do */
                break;
            default:
                zbx_error("unknown response code returned: %d", errcodes[i]);
                THIS_SHOULD_NEVER_HAPPEN;
        }

这里是zbx_deactivate_item_host的代码:

void    zbx_deactivate_item_host(DC_ITEM *item, zbx_timespec_t *ts, const char *error)                       //   #0
{
    const char        *__function_name = "zbx_deactivate_item_host";
    zbx_host_availability_t    in, out;                                                                         //   #1
    unsigned char        agent_type;                                                                          //   #2

    zabbix_log(LOG_LEVEL_DEBUG, "In %s() hostid:" ZBX_FS_UI64 " itemid:" ZBX_FS_UI64 " type:%d",             //   #3
            __function_name, item->host.hostid, item->itemid, (int)item->type);

    zbx_host_availability_init(&in, item->host.hostid);                                                      //   #4
    zbx_host_availability_init(&out,item->host.hostid);                                                      //   #5

    if (ZBX_AGENT_UNKNOWN == (agent_type = host_availability_agent_by_item_type(item->type)))                //   #6
        goto out;

    if (FAIL == host_get_availability(&item->host, agent_type, &in))                                         //   #7
        goto out;

    if (FAIL == DChost_deactivate(item->host.hostid, agent_type, ts, &in.agents[agent_type],                 //   #8
            &out.agents[agent_type], error))
    {
        goto out;
    }

    if (FAIL == db_host_update_availability(&out))                                                           //   #9
        goto out;

    host_set_availability(&item->host, agent_type, &out);                                                    //   #10

    if (0 == in.agents[agent_type].errors_from)                                                              //   #11
    {
        zabbix_log(LOG_LEVEL_WARNING, "%s item \"%s\" on host \"%s\" failed:"                                //   #12
                " first network error, wait for %d seconds",
                zbx_agent_type_string(item->type), item->key_orig, item->host.host,
                out.agents[agent_type].disable_until - ts->sec);
    }
    else
    {
        if (HOST_AVAILABLE_FALSE != in.agents[agent_type].available)                                         //   #13
        {
            if (HOST_AVAILABLE_FALSE != out.agents[agent_type].available)                                    //   #14
            {
                zabbix_log(LOG_LEVEL_WARNING, "%s item \"%s\" on host \"%s\" failed:"                        //   #15
                        " another network error, wait for %d seconds",
                        zbx_agent_type_string(item->type), item->key_orig, item->host.host,
                        out.agents[agent_type].disable_until - ts->sec);
            }
            else
            {
                zabbix_log(LOG_LEVEL_WARNING, "temporarily disabling %s checks on host \"%s\":"              //   #16
                        " host unavailable",
                        zbx_agent_type_string(item->type), item->host.host);
            }
        }
    }

    zabbix_log(LOG_LEVEL_DEBUG, "%s() errors_from:%d available:%d", __function_name,
            out.agents[agent_type].errors_from, out.agents[agent_type].available);
out:
    zbx_host_availability_clean(&out);
    zbx_host_availability_clean(&in);

    zabbix_log(LOG_LEVEL_DEBUG, "End of %s()", __function_name);
}

下