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Tacker (devstack Queens) , tracing VM monitoring function

asked 2018-08-23 08:05:30 -0500

AndyW gravatar image

Hi,

devstack queens with Tacker running on single ubuntu16.04 VM on Ubuntu18.04 Host:

I added the Monitoring function to my VDU in my VNFD : (extract)

node_templates:
    VDU1:
      type: tosca.nodes.nfv.VDU.Tacker
      capabilities:
        nfv_compute:
          properties:
            num_cpus: 1
            mem_size: 512 MB
            disk_size: 1 GB
      properties:
        image:  { get_input: image_name}
        config: |
          param0: key1
          param1: key2
        mgmt_driver: noop
        key_name: mykey
        user_data_format: RAW
        user_data: |
          #!/bin/sh
          echo "my hostname is `hostname`" > /tmp/hostname
          df -h > /home/cirros/diskinfo
        monitoring_policy:
          name: ping
          parameters:
            monitoring_delay: 20
            count: 3
            interval: 2
            timeout: 2
          actions:
            failure: respawn
          retry: 6

am using cirros0.4.0 image

(note some examples in Tacker VNFD doc show addition of port: 22 to the monitoring_policy with ping , seems an error to me as icmp doesn't use a port)

launch VNF and check event list:

tacker vnf-events-list --fit-width

| 144 | vnf           | cb292c70-52 | PENDING_CREATE | CREATE     | 2018-08-2 | VNF UUID       |
|     |               | 22-40a8-a76 |                |            | 3         | assigned.      |
|     |               | 3-e8f41ff1b |                |            | 12:17:58  |                |
|     |               | 931         |                |            |           |                |
| 145 | vnf           | cb292c70-52 | PENDING_CREATE | CREATE     | 2018-08-2 | Infra Instance |
|     |               | 22-40a8-a76 |                |            | 3         | ID created:    |
|     |               | 3-e8f41ff1b |                |            | 12:18:10  | 1cf9bc3a-6c2e- |
|     |               | 931         |                |            |           | 4e12-bb7b-     |
|     |               |             |                |            |           | 1e19e5254e5f   |
|     |               |             |                |            |           | and Mgmt URL   |
|     |               |             |                |            |           | set: {"VDU1":  |
|     |               |             |                |            |           | "192.168.120.3 |
|     |               |             |                |            |           | "}             |
| 146 | vnf           | cb292c70-52 | ACTIVE         | CREATE     | 2018-08-2 | VNF creation   |
|     |               | 22-40a8-a76 |                |            | 3         | completed      |
|     |               | 3-e8f41ff1b |                |            | 12:18:10  |                |
|     |               | 931         |                |            |           |                |
| 147 | vnf           | cb292c70-52 | ACTIVE         | MONITOR    | 2018-08-2 | VNF added for  |
|     |               | 22-40a8-a76 |                |            | 3         | monitoring. mo |
|     |               | 3-e8f41ff1b |                |            | 12:18:10  | n_policy_dict  |
|     |               | 931         |                |            |           | = {"vdus":     |
|     |               |             |                |            |           | {"VDU1":       |
|     |               |             |                |            |           | {"ping":       |
|     |               |             |                |            |           | {"actions":    |
|     |               |             |                |            |           | {"failure":    |
|     |               |             |                |            |           | "respawn"},    |
|     |               |             |                |            |           | "name":        |
|     |               |             |                |            |           | "ping",        |
|     |               |             |                |            |           | "parameters":  |
|     |               |             |                |            |           | {"count": 3,   |
|     |               |             |                |            |           | "interval": 2, |
|     |               |             |                |            |           | "monitoring_de |
|     |               |             |                |            |           | lay": 20,      |
|     |               |             |                |            |           | "timeout": 2}, |
|     |               |             |                |            |           | "retry": 6, "m |
|     |               |             |                |            |           | onitoring_para |
|     |               |             |                |            |           | ms": {"count": |
|     |               |             |                |            |           | 3, "interval": |
|     |               |             |                |            |           | 2, "monitoring |
|     |               |             |                |            |           | _delay": 20,   |
|     |               |             |                |            |           | "timeout":     |
|     |               |             |                |            |           | 2}}}}},        |
+-----+---------------+-------------+----------------+------------+-----------+----------------+

Over several minutes , that Event list stays constant , no further events (a respawn would create several events of course) meaning either the Monitor function is working, or , worse, inactive but reporting as working....

Now, as the Monitoring function for the VNFM is ping, assume that is ICMP to the VM, and as this VM has a single interface , I'd expect the VNFM to ping the VM on that interface every 20 secs as described in policy above.

Now if , on the Host, I tcpdump ICMP traffic on the port connecting the VM (cirros unfortunately doesn't have tcpdump), I see , nothing!

sudo tcpdump -e -i qvof3e71d57-33 icmp

even removing icmp filter see no traffic (except an ARP request from VM)

I have the right port, I believe, as if I ping from the Host the floating IP associated with that VM , then I can see icmp traffic.

So , maybe I've misunderstood how the Ping monitor function should work, either there's another mechanism or it's broken (but falsely reporting a ping to the VNFM)

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answered 2018-08-28 11:24:47 -0500

AndyW gravatar image

My own research so far, Monitor function stability seems unstable

Reran stack.sh for devstack and this time could see the Monitor pings (just the simple Ping) via tcpdump

sudo tcpdump  icmp -i qvo5d02ffd8-81
tcpdump: verbose output suppressed, use -v or -vv for full protocol decode
listening on qvo5d02ffd8-81, link-type EN10MB (Ethernet), capture size 262144 bytes
15:47:28.789322 IP 192.168.120.1 > 192.168.120.8: ICMP echo request, id 7985, seq 2, length 64
15:47:28.789626 IP 192.168.120.8 > 192.168.120.1: ICMP echo reply, id 7985, seq 2, length 64
15:47:48.789388 IP 192.168.120.1 > 192.168.120.8: ICMP echo request, id 7985, seq 3, length 64
15:47:48.789879 IP 192.168.120.8 > 192.168.120.1: ICMP echo reply, id 7985, seq 3, length 64
15:47:58.809428 IP 192.168.120.1 > 192.168.120.8: ICMP echo request, id 17388, seq 1, length 64
15:47:58.809686 IP 192.168.120.8 > 192.168.120.1: ICMP echo reply, id 17388, seq 1, length 64

pings are about every 20secs as policy in VNFD 192.168.120.1 is the vRouter interface (GW ip of net_mgmt private net), 192.168.120.8 is the interface of instance (cirros0.4.0) on net_mgmt.

However, I don't find this functionality (devstack queens) stable:

1) If I ssh from Host to the Floating IP of the VM and do an 'ifdown eth0' , I expected a respawn, but in fact the Monitor just was pronounced DEAD , and no respawn .
I manually deleted VNF and reran a VNF-CREATE but Monitor icmp traffic still did not reappear. I had to restart the tacker service on the Host, THEN I could see my ping traffic again.

2) Other times if I just ssh from Host to Floating IP of VM (again cirros0.4.0 ) then I notice my ssh terminal hangs after 15secs as for some reason tacker monitor does a respawn (Monitor:Dead; Respawn) , cirros is using 1vCPU and 512M memory, but would have thought there are sufficient resources to handle just ping and ssh. Unsure why SSH disrupts Ping traffic . was using following Policy here for Monitor:

 monitoring_policy:
      name: ping
      parameters:
        monitoring_delay: 30
        count: 3
        interval: 20
        timeout: 2
      actions:
        failure: respawn
      retry: 6
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Asked: 2018-08-23 08:05:30 -0500

Seen: 52 times

Last updated: Aug 28 '18