Hi Gorka and Renat

Thanks you for your suggestions and sorry to have forgotten the [mistral] subject prefix .

>Renat:
>workflow should probably be responsible for tracking a status of an operation.

>Gorka:
>Instead of a sleep, which may get you through this issue but fall into a
>different one and won't return the right status code, you should
>probably have a loop checking the status of the backup and return a non
>zero status code if it ends up in "error" state.

The idea of Gorka sounds good.

If you look at the snapshot worflow of Jose Castro, you will find a similar snippet:

    #https://techblog.web.cern.ch/techblog/post/scheduled-snapshots/
    #https://gitlab.cern.ch/cloud-infrastructure/mistral-workflows/raw/master/workflows/instance_snapshot.yaml | sed -e 's%action_region: "cern"%action_region: "ch-zh1"%' >instance_snapshot.yaml

    stop_instance:
      description: 'Stops the instance for consistency'
      action: nova.servers_stop
      input:
        server: <% $.instance %>
        action_region: <% $.action_region %>
      on-success:
        - wait_for_stop_instance
      on-error:
        - error_task

    wait_for_stop_instance:
      description: 'Waits until the instance is shutoff to continue'
      action: nova.servers_find
      input:
        id: <% $.instance %>
        status: 'SHUTOFF'
        action_region: <% $.action_region %>
      retry:
        delay: 5
        count: 40
      on-success:
        - check_boot_source
      on-error:
        - error_task

>We’ve discussed a more generic solution in the past for similar situations but it seems to be virtually impossible to find it.

Ok so it looks that this issue cannot be fixed with a small bugfix.
It would require a feature extension.

I can imagine that quite a few api calls from the different openstack modules/services are asynchronous and would require mistral to check their progress status every time in a different ad hoc manner.
That would make the such a new feature in mistral quite expensive to implement.

It would be great if every async call would return a job_id in a standard form by each service.
So mistral would be able to track them in an uniform way.
This would also allows openstack client to run in sync or async mode, according to the user need.

But such a design requirement better need to be done at day one; it is likely too late to change all openstack services...

However, there is a minor enhancement that could be done:
let the user specify if a cron trigger need to auto-delete itself after its last execution or not.

Keeping expired cron triggers could be nice for:
-avoiding the such racing issues as with swift/radosgw
-allowing the user to edit and reschedule a expired cron trigger

What do you think?

Best Regards

Francois

Hi!

I would kindly ask you to add [mistral] into the subject of the emails related to Mistral. I just saw this thread accidentally (since I can’t read everything) and missed it in the first place.

On the issue itself… So yes, the discovery you made makes perfect sense. I agree that a workflow should probably be responsible for tracking a status of an operation. We’ve discussed a more generic solution in the past for similar situations but it seems to be virtually impossible to find it. If you have some ideas, please share. We can discuss it.

Thanks

Renat Akhmerov
@Nokia

On 23 Sep 2019, 14:41 +0700, Gorka Eguileor <geguileo@redhat.com>, wrote:

On 20/09, Francois Scheurer wrote:

Hi Gorka

Then I assume you prefer the Swift backup driver over the Ceph one
because you are using one of the OpenStack releases that had trouble >with

Incremental Backups on the Ceph backup driver.


You are probably right. But I cannot answer that because I was not involve
in that decision.


Ok in the radosgw logs I see this:


2019-09-20 15:40:06.805529 7f19edb9b700 20 token_id=gAAAAABdhNauRvNev5P90ovX7_cb5_4MkY1tg5JHFpAH8JL-_0vDs06lHW5F9Iphua7fxCWTxxdL-0fRzhR8We_nN6Hx9z3FTWcTXLUMtIUPe0WMKQgW6JkUTP8RwSjAfF4W04OztEg3VAUGN_5gWRlBX-KT9uypnEszadG1yA7gpjkCokNnD8oaIeE6arvs_EjfJib51rao
2019-09-20 15:40:06.805664 7f19edb9b700 20 sending request to
https://keystone.service.stage.ewcs.ch/v3/auth/tokens
2019-09-20 15:40:06.805803 7f19edb9b700 20 ssl verification is set to off
2019-09-20 15:40:07.235356 7f19edb9b700 20 sending request to
https://keystone.service.stage.ewcs.ch/v3/auth/tokens
2019-09-20 15:40:07.235404 7f19edb9b700 20 ssl verification is set to off
2019-09-20 15:40:07.267091 7f19edb9b700  5 Failed keystone auth from
https://keystone.service.stage.ewcs.ch/v3/auth/tokens with 404
BTW: our radosgw is configured to delegate user authentication to keystone.

In keystone logs I see this:

2019-09-20 15:40:07.218 24 INFO keystone.token.provider
[req-21b2f11c-9e67-4487-af05-420acfb65ace - - - - -] Token being processed:
token.user_id [f7c7296949f84a4387c5172808a0965b],
token.expires_at[2019-09-21T13:40:07.000000Z],
token.audit_ids[[u'hFweMPCrSO2D00rNcRNECw']], token.methods[[u'password']],
token.system[None], token.domain_id[None],
token.project_id[4120792f50bc4cf2b4f97c4546462f06], token.trust_id[None],
token.federated_groups[None], token.identity_provider_id[None],
token.protocol_id[None],
token.access_token_id[None],token.application_credential_id[None].
2019-09-20 15:40:07.257 21 INFO keystone.common.wsgi
[req-9f858abb-68f9-42cf-b71a-f1cafca91844 f7c7296949f84a4387c5172808a0965b
4120792f50bc4cf2b4f97c4546462f06 - default default] GET
http://keystone.service.stage.ewcs.ch/v3/auth/tokens
2019-09-20 15:40:07.265 21 WARNING keystone.common.wsgi
[req-9f858abb-68f9-42cf-b71a-f1cafca91844 f7c7296949f84a4387c5172808a0965b
4120792f50bc4cf2b4f97c4546462f06 - default default] Could not find trust:
934ed82d2b14413899023da0bee6a953.: TrustNotFound: Could not find trust:
934ed82d2b14413899023da0bee6a953.


So what happens is following:

1. when the user creates the cron trigger, mistral creates a trust
2. when the cron trigger executes the workflow, openstack create a
volume snapshot (a rbd image) then copy it to swift (rgw) then
delete the snapshot
3. when the execution finishes, if the cron trigger has no remaining
executions scheduled, then mistral remove the cron trigger and the trust

The problem is a racing issue: apprently the copying of the snapshot to
swift run in the background and mistral removes the trust before the
operation completes...

That explains the error in keystone and also the cron trigger execution
result which is "success" even if the resulting backup is actually "failed".


To test this theory I set up the same cron trigger with more than one
scheduled execution and the backups were suddenly created correctly ;-).


So something need to be done on the code to deal with this racing issue.

In the meantime, I will try to put a sleep action after the 'create backup'
action.

Hi,

Congrats on figuring out the issue. :-)

Instead of a sleep, which may get you through this issue but fall into a
different one and won't return the right status code, you should
probably have a loop checking the status of the backup and return a non
zero status code if it ends up in "error" state.

Cheers,
Gorka.

Best Regards

Francois











On 9/20/19 4:02 PM, Gorka Eguileor wrote:

On 20/09, Francois Scheurer wrote:

Hi Gorka


We have a swift endpoint set up on opentstack, which points to our ceph
radosgw backend

Radosgw provides s3 & swift.

So the swift logs are here actually the radosgw logs.

Hi,

OK, thanks for the clarification.

Then I assume you prefer the Swift backup driver over the Ceph one
because you are using one of the OpenStack releases that had trouble
with Incremental Backups on the Ceph backup driver.

Cheers,
Gorka.

Cheers

Francois



On 9/20/19 2:46 PM, Gorka Eguileor wrote:

On 20/09, Francois Scheurer wrote:

Dear Gorka and Hervé


Thanks for your hints.

I have set the debug log level on radosgw.

I will retest now and post here the results.


Cheers

Francois

Hi,

Sorry, I may have missed something in the conversation, weren't you
using Swift?

I think you need to see the Swift logs as well, since that's the API
service that complained about the authorization.

Cheers,
Gorka.

--


EveryWare AG
François Scheurer
Senior Systems Engineer
Zurlindenstrasse 52a
CH-8003 Zürich

tel: +41 44 466 60 00
fax: +41 44 466 60 10
mail: francois.scheurer@everyware.ch
web: http://www.everyware.ch

--


EveryWare AG
François Scheurer
Senior Systems Engineer
Zurlindenstrasse 52a
CH-8003 Zürich

tel: +41 44 466 60 00
fax: +41 44 466 60 10
mail: francois.scheurer@everyware.ch
web: http://www.everyware.ch

--


EveryWare AG
François Scheurer
Senior Systems Engineer
Zurlindenstrasse 52a
CH-8003 Zürich

tel: +41 44 466 60 00
fax: +41 44 466 60 10
mail: francois.scheurer@everyware.ch
web: http://www.everyware.ch

-- 


EveryWare AG
François Scheurer
Senior Systems Engineer
Zurlindenstrasse 52a
CH-8003 Zürich

tel: +41 44 466 60 00
fax: +41 44 466 60 10
mail: francois.scheurer@everyware.ch
web: http://www.everyware.ch