Simon, you should have joined the discussion sooner.
I believe that now we might actually be able to get to the bottom of this.
Inline comments
----- Original Message -----
From: "Simon Grinberg" <simon(a)redhat.com>
To: "Saggi Mizrahi" <smizrahi(a)redhat.com>
Cc: vdsm-devel(a)lists.fedorahosted.org, "Dan Yasny" <dyasny(a)redhat.com>,
"Ayal Baron" <abaron(a)redhat.com>
Sent: Thursday, February 16, 2012 1:11:46 PM
Subject: Re: [vdsm] flowID schema
Lot's of stuff inline,
----- Original Message -----
> From: "Saggi Mizrahi" <smizrahi(a)redhat.com>
> To: "Simon Grinberg" <simon(a)redhat.com>
> Cc: vdsm-devel(a)lists.fedorahosted.org, "Dan Yasny"
> <dyasny(a)redhat.com>, "Ayal Baron" <abaron(a)redhat.com>
> Sent: Thursday, February 16, 2012 7:02:02 PM
> Subject: Re: [vdsm] flowID schema
>
> Pinning down specific moments where stuff went horribly wrong is
> usually quite simple. The only reason I can't think of for someone
> to track a problem is if there was a bug in the storage subsystem
> that cause a corruption that only became apparent later on. But
> this
> can't benefit from flowID.
>
> I'm going to to day this again. I want to hear someone to give a
> case
> where this is useful. Don't say things like.
> "It will allow me to do X"
Allows me to do X is a valid argument if I believe X based on my
experience (16 years out of which 4 of them is ovirt or whatever is
was called at a specific time) debug is helpful or time saving.
Based on my,
admittedly less rich background, there are many cases where people think they need
something when actually need something else.
The thing is I understand that people are having a hard time debugging issues in ovirt.
There is no argument there. The argument is on what is the best way to go about solving
this.
I don't just want to hear, "I want a hammer". Nor would I would like to
hear, "I had to nail nails to a plank but because I didn't have a hammer it took
me a lot of time". I want to hear, "Someone came complaining about a hole in his
wall and the cold wind was getting in. I looked at the hole and decided that nailing a
plank covering the hole would fix the problem. Because I didn't have a hammer it took
me a lot of time".
Putting the argument this way opens up the possibility of alternative solutions to the
problem instead of arguing whether the problem exists or whether this solution is the only
possible one. Going back to the allegory, I could say, "We already have a drill and
screws, you could have used that. There is no need for a hammer".
The thing is I don't *understand* what is the issue we are trying to solve.
> or
> "I know of a guy who spent 2 years doing X to VDSM\Engine logs"
>
> I want an example like:
>
> The user complained about X. So I had to do Y to figure out what is
> wrong and it was a pain.
I actually did it myself plenty of times - sometimes 20 hours strait
just to understand what the hell was going wrong. Now think about a
sysadmin or a front line support person?
To tell you that I recall the exact details of every case would be
just too much.
One or two would suffice.
>
> The Only reason I can think of is someone trying to figure out what
> wrong knowing nothing about how VDSM\Engine works.
> While I just jump from place to place because I know what is going
> on, other people would just want to go step by step to get the
> complete picture.
Exactly - This person is called your end user.
Unless it's only intended to use by the development community
I actually
addressed that in the next paragraph.
>
> But even with that I don't see why you would want to keep going
> from
> the Engine down to VDSM and back out again.
>
> Other then that I just simply can't imagine a use case where I'd
> need
> to do the stuff you talk about.
> But again, I usually get my bug reports from QA and QE, and they
> are
> more skilled at bug reporting then the general public.
Right - you get your cases after someone else has actually did the
initial time consuming search through the logs to get you around the
place that the issue actually occurred.
People already analyzed the engine logs, ruled out other issues, got
to the understanding that this issue is related to storage (in your
case) and not to other modules in VDSM and even got to the suspected
operation that have failed.
Guess who this someone was in numerous cases coming from customers in
the middle of the night?
I to had to figure out various bugs that ended up being in
weird places.
>
> Further more, WHAT IS A FLOW? When does it start? When does it end?
> create Image is a flow? is the connect to the domain included?
> isn't
> it all just part of a big flow to create a VM? Does the engine even
> track it as a flow?
>
> Flows depend on the debugger the problem and the scope.
Indeed :)
I didn't say it is easy, a flow definition is something elusive and
may change context according to operation types.
PS.
A good design actually starts with flows (user flows) and then
translated to design.
You have a UI to lock a user to specific "user
flows". But the program should be designed around the abstract concepts of the
entities at play. The "flow" should just be one way of using the internal
entities. "User Flows" change all the time. If you abstracted the entity
correctly you will be able to modify the program more easily. Ovirt is actually built that
way. A "user flow" could be a script using the RHEV API.
A lot of people treat flows as a composite. Big flow containing little flows that contain
smaller flows. This true if you look through the view point of the *user* the problem that
if you try and look from the view point an entity you actually get a cross cutting flow.
When debugging a lot of the time people try and follow the user flow. This, I guess, is
because of using an interactive debugger too much. When doing a postmortem, you usually
have an actual complaint. This issue is tied to an entity. Being able to follow that
entity is what you actually want to do. Not to follow the user flow.
If I know that the value of i came out wrong. I don't care what exactly happened at
every point. I just want to know when and where i changed to and to what value.
To sum up:
I don't think a "flow" is an entity you want to track, ever. Further more, I
don't think you can define such entity correctly in VDSM or the Engine as they each
have independent flows and some flows that are controlled by higher beings (GUIs,
scripts).
Again, I implore, someone please send an example use case. I'm not just saying this.
Unless I know what this feature will be used for I can't design it correctly as
currently I don't understand why one would need such a thing.
>Throwing
> another useless ID in the pile will give you nothing. What you want
> is to be able to map sophisticated connections between resources
> and
> operations inside every component and between them. For instance,
> in
> VDSM. To track a resource locking issues you use the resourceID. It
> crosses "flows". To debug connection issues you use the connection
> information (and soon, the reference ID). An it crosses "flows" as
> well.
>
> I'm not saying that debugging Ovirt is easy. I'm just saying that
> this is not the solution IMHO. Good anchors to resources like
> taskIDs, connection reference IDs, domain IDs and resource IDs give
> you the ability to track whatever you want. You just need better
> tools to cross reference them across log files so that the log
> tricks I *know* are implemented in a way that everyone can use
> them.
Very good, if you'll write it then you don't need flows - but this
tool needs to come with the engine :)
However you will loose the benefit of catching design/architectural
issues that are often discovered when you put some thought into what
are your flows while you do the design.
Don't get me wrong, I'm not saying that flows are the only valid
solution, everything you say makes a lot of sense, and everything
you've suggested is important and I'll vote for it. Flows (if we
agree on this) should be on top not instead. Farther more flows will
not solve all the illness of the world and even if you'll do
everything that you've just mentioned above I'll be happy.
The problem is that the more you wait, the harder it is to do it.
In this specific case that so much is already written - it may make
sense to try first everything you've suggested and then wait for a
feedback on the new logs usability. As I've said flow ID is on top
not instead. As long as you'll be willing to except more API changes
:).
>
> This is when good tools come in to play. Think about it like a DB.
> Should something be a table with an index or should it just be a
> view.
>
> (more inline)
>
> ----- Original Message -----
> > From: "Simon Grinberg" <simon(a)redhat.com>
> > To: "Saggi Mizrahi" <smizrahi(a)redhat.com>
> > Cc: vdsm-devel(a)lists.fedorahosted.org, "Dan Yasny"
> > <dyasny(a)redhat.com>, "Ayal Baron" <abaron(a)redhat.com>
> > Sent: Thursday, February 16, 2012 11:07:34 AM
> > Subject: Re: [vdsm] flowID schema
> >
> >
> >
> > ----- Original Message -----
> > > From: "Saggi Mizrahi" <smizrahi(a)redhat.com>
> > > To: "Simon Grinberg" <simon(a)redhat.com>
> > > Cc: vdsm-devel(a)lists.fedorahosted.org, "Dan Yasny"
> > > <dyasny(a)redhat.com>, "Ayal Baron"
<abaron(a)redhat.com>
> > > Sent: Thursday, February 16, 2012 5:18:26 PM
> > > Subject: Re: [vdsm] flowID schema
> > >
> > > You could just cross check flowID (that is printed in RHEV-M to
> > > all
> > > the call IDs in that flow, It's a simple enough tool to make).
> > >
> > > Also if you look at the way VDSM is heading you will see that
> > > just
> > > grepping for the flow ID will gradually give you a smaller and
> > > smaller picture of the actual flow.
> > >
> > > - The new connection management means that the actual connect
> > > is
> > > not
> > > a direct part of the flow anymore.
> > > - We plan to have a similar mechanism for domains.
> > > - The new image code will do a lot of things "out of band".
> > > - There will be more flows using multiple hosts because of SDM
> > > and
> > > the increased safety gained by sanlock and they will not share
> > > the
> > > flow ID in internal communication.
> > > - Engine actually polls all tasks in a single thread (with it's
> > > own
> > > flow ID? No flowID?) so even the actual result for async tasks
> > > might
> > > have a different flowID in the VDSM log.
> >
> > OK so they may be a terminology mismatch here:
> > A flow as an end user would see it is: Everything that happened
> > since
> > the moment he clicked "OK" and to the moment the operation failed
> > succeeded.
> > Same goes for internal/auto triggered actions in response to an
> > event
> > (Storage failure etc).
> >
> > It may be composed as you notes above of several connections,
> > multiple tasks etc.
> > The flow ID as I see it is the linkage that makes sense in all of
> > these. Everything that you've wrote above just convinces me that
> > such an ID is a must.
> I understood that. The point is that the system is too complex to
> be
> able to find certain operations to flows.
> If you connect in FlowX but use a resource provided by the
> connection
> in flowY. The connection breaks and you loose the resource.
> As long as you somehow pinned the flowID value to the connection
> object it might be logged as flowX. The actual problem happened in
> flowY.
This someone is called oVirt engine
> My point is that the logical leaps required to extract only
> relevant
> data to a flow are impossible at run time as VDSM is too low in the
> stack to know the context and figure out what's related and what
> isn't. For simple log syncing you could just force users to use
> NTP.
Agree - This is why I've defined a flow as something initiated by the
end user/event.
It should not be up to VDSM to determine the flow ID it is given to
it.
It is up to the engine to determine flow id.
> >
> >
> > >
> > > In order to keep flowID sane in that kind of environment, there
> > > will
> > > have to be a lot of code moving that value around just to log
> > > it.
> >
> > Indeed, write well once and serve many later, that is what coding
> > is
> > all about.
> > If you do it while you code you'll simplify the external tools
> > required while making even manual debug tasks more reasonable.
> > And
> > more important - faster
> >
> > It is called Design for Debug!!! And in hardware world, it
> > consumes
> > 20% more resources. It saves much more afterwards.
> >
> > Most important, it will save escalations to developers, meaning
> > that
> > a developer that will invest in that actually does this for his
> > own
> > sanity (unless he does not care :)). The easier it is to debug
> > the
> > system by the end user first then by community as an escalation
> > point and only then developers, the more time you'll have to do
> > what
> > you love to do best - develop.
> >
> > Remember, developers are few, community is larger and users (if
> > you
> > are lucky) are in order of magnitudes larger. Every effort you
> > spend
> > in the design phase to reduce escalations will reward you later.
> >
> >
> >
> > >
> > > What we really need is something like the systemd journal
> > > (
http://bit.ly/vbZEBQ).
> > > The project is still in it's infancy but the actual ideas are
> > > solid.
> > > * Always log in UTC
> > > * Log in a query-able format with typed key\value pairs instead
> > > of
> > > just free text messages
> > > * Use MSGID for *some* of the more important log lines for easy
> > > matching (and use UUID for MSGID instead of a rolling number)
> >
> > That is a good start - always good to have regardless of the
> > above
> > discussion.
> >
> > >
> > > With this kind of format you can easily write tools that sync
> > > up
> > > logs
> > > and do any other post processing.
> > > It will also allow us to easily migrate to the systemd journal
> > > when
> > > it's available.
> > >
> > > We could just log to an sqlite db but I have a felling the
> > > constant
> > > fsyncing\flocking will be a performance issue.
> >
> > Some will agree, some will disagree, not sure that having another
> > DB
> > in the system is advisable.
> >
> > >
> > > So I suggest implementing this by having a log target which
> > > writes
> > > json objects and have a tool to put it all in an sqlite DB when
> > > necessary. This way you don't get a performance hit for doing
> > > something drastically different then appending to text files
> > > but
> > > you
> > > can later easily "pack" the logs to a db file that can easily
> > > be
> > > navigated, merged and processed.
> > >
> > > You could get the "classic view" by just using the msg field
> > > from
> > > the
> > > json object for each line. You could do that without going
> > > through
> > > the "packing" process so it's instantly available.
> > >
> > > I've been pondering this for quite some time and this might be
> > > a
> > > good
> > > excuse to give it a shot. As long as all the components in
> > > OVIRT
> > > write json objects we could merge all logs together to a single
> > > log
> > > db.
> > > You could then try and detect small time time drifts using
> > > heuristics
> > > and have a unified view of everything.
> > >
> > > I can do a more in depth write up if people think it's a good
> > > direction to go to.
> > >
> > > ----- Original Message -----
> > > > From: "Simon Grinberg" <simon(a)redhat.com>
> > > > To: "Ayal Baron" <abaron(a)redhat.com>, "Saggi
Mizrahi"
> > > > <smizrahi(a)redhat.com>
> > > > Cc: vdsm-devel(a)lists.fedorahosted.org, "Dan Yasny"
> > > > <dyasny(a)redhat.com>
> > > > Sent: Wednesday, February 15, 2012 5:50:34 AM
> > > > Subject: Re: [vdsm] flowID schema
> > > >
> > > > Hi Ayal,
> > > >
> > > > > > actual use case where someone would have actually
> > > > > > benefited
> > > > > > from
> > > > > > this.
> > > >
> > > >
> > > > Sorry joining that late into the discussion.
> > > >
> > > > Forget the automatic analyses/past issues recognition that
> > > > may
> > > > or
> > > > may
> > > > not be possible if we do have flow ID. (Personally I believe
> > > > it's
> > > > possible for known issues)
> > > >
> > > > Think of large setups, not the few hosts setups that are
> > > > running
> > > > in
> > > > the labs.
> > > > Dozens of hosts, hundreds of VMs and tasks, running for few
> > > > months.
> > > > --->>> Huge logs (yes we even got 50G sized logs)
> > > >
> > > > Now try to do what you and Saggy are suggesting said, yes it
> > > > will
> > > > work!!! Sometimes it is the only approach that will be
> > > > possible.
> > > >
> > > > But what about efficiency?
> > > >
> > > > Some times I found myself spending 30 minutes just getting to
> > > > the
> > > > files that I need to view and to the approximate location of
> > > > the
> > > > error.
> > > > If you have a flow ID you can have a tool that will extract
> > > > all
> > > > the
> > > > relevant information from all the hosts participating in that
> > > > flow
> > > > and correlate that with the rhevm.log as the anchor.
> > > >
> > > > (Valdik actually wrote a tool that follows the SPM and
> > > > creates
> > > > an
> > > > SPM
> > > > log no matter on which host it resides - this allowed
> > > > tracking
> > > > flows
> > > > and proved itself useful and time saving, especially since
> > > > when
> > > > storage issues begin SPM tends to move around :))
> > > >
> > > > In addition to that think about skill levels,
> > > > For you it's very easy to go and debug, you wrote the code,
> > > > you
> > > > know
> > > > what to expect and what is the normal behavior (most of the
> > > > time).
> > > > But what about others?
> > > > When encountering an issue within a flow for a front line or
> > > > a
> > > > customer self debug the easiest way will be to actually
> > > > compare
> > > > it
> > > > to the same flow that succeed (if exist) and understand what
> > > > was
> > > > supposed to happen next (or before) and did not. I actually
> > > > used
> > > > that technique a lot. Again a flow ID will save time. All you
> > > > have
> > > > to do is extract an identical flow that worked using the
> > > > flow-extractor utility and then compare.
> > > >
> > > >
> > > > I agree that when you get to the really tough cases, they
> > > > will
> > > > span
> > > > across flows and your only alternative may be just to dig in.
> > > > However for many others, flows tracking will save support
> > > > calls,
> > > > support escalations and will considerably help with
> > > > education.
> > > > For
> > > > 2.2 we had Marina going into the code and documenting flows,
> > > > so
> > > > support people can learn what to expect and what to look for
> > > > in
> > > > the
> > > > logs.
> > > >
> > > > I believe it will also help engineering, lot's of times I had
> > > > to
> > > > gather 3 engineers and sat together just to understand a flow
> > > > in
> > > > order to debug an issue or understand what to expect if
> > > > someone
> > > > complained about a weird behavior. Since each of them only
> > > > new
> > > > what
> > > > his part is doing - all had to go into their code and
> > > > discuss.
> > > > With
> > > > flow ID you can just extract the flow and easily see what is
> > > > being
> > > > done (you may find out as happened before that it's not
> > > > exactly
> > > > what
> > > > they meant to do)
> > > >
> > > > In short, if we aim to look at RHEV as a system, flows are
> > > > helpful
> > > > in
> > > > many aspects. Instead of having discrete components and
> > > > requiring
> > > > a
> > > > high level of expertise and spending a lot of time (finding
> > > > the
> > > > right spot) to debug even minor issues you can look at a
> > > > system
> > > > and
> > > > easily get (most of the time), understand what to expect and
> > > > get
> > > > to
> > > > the most relevant logs fairly fast.
> > > >
> > > > Simon.
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > >
> > > > ----- Original Message -----
> > > > > From: "Dan Yasny" <dyasny(a)redhat.com>
> > > > > To: "Ayal Baron" <abaron(a)redhat.com>
> > > > > Cc: "Simon Grinberg" <simon(a)redhat.com>,
> > > > > vdsm-devel(a)lists.fedorahosted.org
> > > > > Sent: Friday, February 10, 2012 4:01:01 PM
> > > > > Subject: Re: [vdsm] flowID schema
> > > > >
> > > > >
> > > > >
> > > > > ----- Original Message -----
> > > > > > From: "Ayal Baron" <abaron(a)redhat.com>
> > > > > > To: "Dan Yasny" <dyasny(a)redhat.com>
> > > > > > Cc: "Simon Grinberg" <simon(a)redhat.com>,
> > > > > > vdsm-devel(a)lists.fedorahosted.org
> > > > > > Sent: Friday, 10 February, 2012 3:51:01 PM
> > > > > > Subject: Re: [vdsm] flowID schema
> > > > > >
> > > > > >
> > > > > >
> > > > > > ----- Original Message -----
> > > > > > >
> > > > > > >
> > > > > > > ----- Original Message -----
> > > > > > > > From: "Ayal Baron"
<abaron(a)redhat.com>
> > > > > > > > To: "Dan Yasny"
<dyasny(a)redhat.com>
> > > > > > > > Cc: "Simon Grinberg"
<simon(a)redhat.com>,
> > > > > > > > vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > Sent: Friday, 10 February, 2012 2:55:46 PM
> > > > > > > > Subject: Re: [vdsm] flowID schema
> > > > > > > >
> > > > > > > >
> > > > > > > >
> > > > > > > > ----- Original Message -----
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > ----- Original Message -----
> > > > > > > > > > From: "Ayal Baron"
<abaron(a)redhat.com>
> > > > > > > > > > To: "Dan Yasny"
<dyasny(a)redhat.com>
> > > > > > > > > > Cc: "Simon Grinberg"
<simon(a)redhat.com>,
> > > > > > > > > > vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > > > Sent: Friday, 10 February, 2012
12:50:04 AM
> > > > > > > > > > Subject: Re: [vdsm] flowID schema
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > ----- Original Message -----
> > > > > > > > > > > > From: "Saggi
Mizrahi" <smizrahi(a)redhat.com>
> > > > > > > > > > > > To: "Keith
Robertson" <kroberts(a)redhat.com>
> > > > > > > > > > > > Cc: "VDSM Project
Development"
> > > > > > > > > > > >
<vdsm-devel(a)lists.fedorahosted.org>
> > > > > > > > > > > > Sent: Thursday, February 9,
2012 2:24:44 PM
> > > > > > > > > > > > Subject: Re: [vdsm] flowID
schema
> > > > > > > > > > > >
> > > > > > > > > > > > -1
> > > > > > > > > > > >
> > > > > > > > > > > > I agree that for messaging
environment having
> > > > > > > > > > > > a
> > > > > > > > > > > > Message
> > > > > > > > > > > > ID
> > > > > > > > > > > > is
> > > > > > > > > > > > a
> > > > > > > > > > > > must
> > > > > > > > > > > > because you sometimes
don't have a particular
> > > > > > > > > > > > target
> > > > > > > > > > > > so
> > > > > > > > > > > > when
> > > > > > > > > > > > you
> > > > > > > > > > > > get
> > > > > > > > > > > > a response you need to know
what this node is
> > > > > > > > > > > > actually
> > > > > > > > > > > > responding
> > > > > > > > > > > > to.
> > > > > > > > > > > >
> > > > > > > > > > > > The message ID could be
composed with
> > > > > > > > > > > > <FLOWID><MSGID>
> > > > > > > > > > > > so
> > > > > > > > > > > > you
> > > > > > > > > > > > can
> > > > > > > > > > > > reuse the field.
> > > > > > > > > > > >
> > > > > > > > > > > > But that is all besides the
point.
> > > > > > > > > > > >
> > > > > > > > > > > > I understand that someone
might find it fun
> > > > > > > > > > > > to
> > > > > > > > > > > > go
> > > > > > > > > > > > on
> > > > > > > > > > > > following
> > > > > > > > > > > > the
> > > > > > > > > > > > entire flow in the Engine and
in VDSM. But I
> > > > > > > > > > > > would
> > > > > > > > > > > > like
> > > > > > > > > > > > to
> > > > > > > > > > > > hear
> > > > > > > > > > > > an
> > > > > > > > > > > > actual use case where someone
would have
> > > > > > > > > > > > actually
> > > > > > > > > > > > benefited
> > > > > > > > > > > > from
> > > > > > > > > > > > this.
> > > > > > > > > > > > As I see it having VSDM
return the task ID
> > > > > > > > > > > > with
> > > > > > > > > > > > every
> > > > > > > > > > > > response
> > > > > > > > > > > > (and
> > > > > > > > > > > > not just for async tasks) is
a lot more
> > > > > > > > > > > > useful
> > > > > > > > > > > > and
> > > > > > > > > > > > correct.
> > > > > > > > > > >
> > > > > > > > > > > Actually, the only way to
understand what
> > > > > > > > > > > happened
> > > > > > > > > > > in
> > > > > > > > > > > a
> > > > > > > > > > > certain
> > > > > > > > > > > flow
> > > > > > > > > > > is to follow it through. From the
engine log
> > > > > > > > > > > where
> > > > > > > > > > > an
> > > > > > > > > > > action
> > > > > > > > > > > was
> > > > > > > > > > > initiated, down to the hosts that
did the
> > > > > > > > > > > execution.
> > > > > > > > > > > Everything
> > > > > > > > > > > RHEV
> > > > > > > > > > > does is a flow, and with no
correlation between
> > > > > > > > > > > hosts
> > > > > > > > > > > executing
> > > > > > > > > > > parts of the same flow,
troubleshooting turns
> > > > > > > > > > > into
> > > > > > > > > > > guesswork,
> > > > > > > > > > > because the only contact point
left is time,
> > > > > > > > > > > which
> > > > > > > > > > > is
> > > > > > > > > > > useless
> > > > > > > > > > > when
> > > > > > > > > > > you're talking about vdsm -
there are sometimes
> > > > > > > > > > > hundreds
> > > > > > > > > > > of
> > > > > > > > > > > log
> > > > > > > > > > > records in a single second, and
not every host
> > > > > > > > > > > is
> > > > > > > > > > > in
> > > > > > > > > > > absolute
> > > > > > > > > > > sync
> > > > > > > > > > > with every other.
> > > > > > > > > >
> > > > > > > > > > What are you talking about? you know
exactly what
> > > > > > > > > > operation
> > > > > > > > > > the
> > > > > > > > > > engine ran at vdsm level.
> > > > > > > > >
> > > > > > > > > Not always true. Haven't had much chance
to deeply
> > > > > > > > > dive
> > > > > > > > > into
> > > > > > > > > 3.0
> > > > > > > > > logs, and if things changed there, it's
already a
> > > > > > > > > huge
> > > > > > > > > step
> > > > > > > > > in
> > > > > > > > > the
> > > > > > > > > right direction.
> > > > > > > >
> > > > > > > > engine logs now always log calls to vdsm.
> > > > > > >
> > > > > > > finally! :)
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > > If it's a task then you also have a
task
> > > > > > > > > > id which is a uuid so you don't
need anything
> > > > > > > > > > else.
> > > > > > > > >
> > > > > > > > > Right, but 1. not everything is a task and
> > > > > > > >
> > > > > > > > Perhaps that should be fixed...
> > > > > > > >
> > > > > > > > > 2. tasks spawn other tasks, and need to be
followed
> > > > > > > > > through
> > > > > > > > > for
> > > > > > > > > that
> > > > > > > >
> > > > > > > > In vdsm? no they don't
> > > > > > >
> > > > > > > Err, ok, in the engine then. The point being, a flow
> > > > > > > like
> > > > > > > MoveMultipleImages (pardon my bad memory for
spelling)
> > > > > > > spawns
> > > > > > > several tasks, and even within those tasks
there's
> > > > > > > usually
> > > > > > > more
> > > > > > > than
> > > > > > > a single flow.
> > > > > > >
> > > > > > > >
> > > > > > > > > 3. long running tasks are hell to debug,
because
> > > > > > > > > they
> > > > > > > > > span
> > > > > > > > > several
> > > > > > > > > log files and thousands lines of logs
> > > > > > > >
> > > > > > > > flowid would not solve this in any way.
> > > > > > > > All you need to do to see the entire task is grep
the
> > > > > > > > taskID
> > > > > > > > as
> > > > > > > > the
> > > > > > > > thread name is the taskID
> > > > > > >
> > > > > > > which causes me to
> > > > > > > 1. jump between engine and vdsm logs, comparing task
> > > > > > > IDs
> > > > > > > and
> > > > > > > actions.
> > > > > > > 2. do it many times in case of a complex flow
> > > > > > >
> > > > > > > Seeing the entire thing on RHEV/oVirt as a system
would
> > > > > > > make
> > > > > > > a
> > > > > > > better
> > > > > > > picture, and being able to grep the entire set of
logs
> > > > > > > for
> > > > > > > a
> > > > > > > single
> > > > > > > ID is a huge plus, since it would produce one large
log
> > > > > > > that
> > > > > > > (hopefully, and if everything is done right) shows
the
> > > > > > > full
> > > > > > > flow,
> > > > > > > step by step, everywhere it took place
> > > > > >
> > > > > > Which is never what you really want as it is pretty
> > > > > > useless.
> > > > > > What
> > > > > > you want is the point of failure and a few hundred lines
> > > > > > before.
> > > > >
> > > > > The problem is - the point of failure is not always the
> > > > > point
> > > > > with
> > > > > the python traceback. This is why a flow should be
> > > > > follow-able
> > > > >
> > > > > > The rest is just distraction which is the point of this
> > > > > > thread.
> > > > > > I
> > > > > > have never encountered a case where I needed such a flow
> > > > > > to
> > > > > > debug
> > > > > > an
> > > > > > issue (even when it spread across multiple hosts).
> > > > >
> > > > > No, the rest is an indication of flow progress, which can
> > > > > help
> > > > > with
> > > > > troubleshooting of issues that don't end in an error. Like
> > > > > performance and scalability issues
> > > > >
> > > > >
> > > > > >
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > > In addition, now that engine logs
results, you
> > > > > > > > > > can
> > > > > > > > > > just
> > > > > > > > > > grep
> > > > > > > > > > that
> > > > > > > > > > instead of a flow id and land at the
exact
> > > > > > > > > > correct
> > > > > > > > > > command
> > > > > > > > > > and
> > > > > > > > > > not
> > > > > > > > > > have to figure out which out of the 5
run in this
> > > > > > > > > > flow
> > > > > > > > > > is
> > > > > > > > > > the
> > > > > > > > > > relevant one.
> > > > > > > > >
> > > > > > > > > Haven't seen that yet, but again, what
are results?
> > > > > > > > > When
> > > > > > > > > the
> > > > > > > > > failure
> > > > > > > > > is somewhere in the middle of the flow, the
> > > > > > > > > resulting
> > > > > > > > > failure
> > > > > > > > > can
> > > > > > > > > be
> > > > > > > > > totally irrelevant.
> > > > > > > >
> > > > > > > > When you have the failure message then all you
have
> > > > > > > > to
> > > > > > > > do
> > > > > > > > is
> > > > > > > > grep
> > > > > > > > it
> > > > > > > > in the log and reach the exact call that failed.
> > > > > > > > Just
> > > > > > > > search
> > > > > > > > for
> > > > > > > > "ERROR|FAILED" above that and you reach
the place of
> > > > > > > > error.
> > > > > > >
> > > > > > > It's the typical approach to logs, that works for
other
> > > > > > > systems.
> > > > > > > With
> > > > > > > RHEV, just finding the traceback is never the
solution,
> > > > > > > because
> > > > > > > it
> > > > > > > shows where everything finally went offhill, instead
of
> > > > > > > where
> > > > > > > the
> > > > > > > error happened.
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > If you could give a real example where
this would
> > > > > > > > > > be
> > > > > > > > > > beneficial
> > > > > > > > > > (i.e.
> > > > > > > > > > log excerpts, how you correlated them
and how
> > > > > > > > > > flow
> > > > > > > > > > id
> > > > > > > > > > would
> > > > > > > > > > have
> > > > > > > > > > eased your job) that would be great.
> > > > > > > > >
> > > > > > > > > Don't have these handy, guess Vladik,
who was
> > > > > > > > > collecting
> > > > > > > > > interesting
> > > > > > > > > fail flows could have helped.
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > > Note that I've also discussed this
with Yaniv
> > > > > > > > > > from
> > > > > > > > > > qe
> > > > > > > > > > who
> > > > > > > > > > said
> > > > > > > > > > they
> > > > > > > > > > don't really need it.
> > > > > > > > >
> > > > > > > > > I'm not saying I want to see a flow ID
as such,
> > > > > > > > > what
> > > > > > > > > I
> > > > > > > > > _am_
> > > > > > > > > saying
> > > > > > > > > is
> > > > > > > > > that flows are important, and we need an
easy way
> > > > > > > > > of
> > > > > > > > > following
> > > > > > > > > them
> > > > > > > > > through.
> > > > > > > > > When a user starts a process in the engine,
it
> > > > > > > > > should
> > > > > > > > > be
> > > > > > > > > clearly
> > > > > > > > > logged and marked, then it should
consistently
> > > > > > > > > report
> > > > > > > > > progress
> > > > > > > > > and
> > > > > > > > > interim outputs, say which host was picked
for what
> > > > > > > > > action,
> > > > > > > > > and
> > > > > > > > > how
> > > > > > > > > that action can be identified in the vdsm
logs.
> > > > > > > >
> > > > > > > > That's fine (although periodic logging causes
log
> > > > > > > > overflow)
> > > > > > >
> > > > > > > Can't those be aggregated somehow? Or sent into a
> > > > > > > different
> > > > > > > log?
> > > > > > > There was even an idea of maintaining a local db for
> > > > > > > logging
> > > > > > > instead
> > > > > > > of plaintext, sqlite would serve for that purpose
> > > > > > >
> > > > > > > >
> > > > > > > > >
> > > > > > > > > We cannot rely on timing. We cannot rely on
> > > > > > > > > everyone
> > > > > > > > > knowing
> > > > > > > > > obscure
> > > > > > > > > engine/vdsm action naming conventions, that
are not
> > > > > > > > > exactly
> > > > > > > > > the
> > > > > > > > > same
> > > > > > > > > as they look in the GUI. A person with no
> > > > > > > > > understanding
> > > > > > > > > of
> > > > > > > > > engine
> > > > > > > > > and vdsm internals, should be able to easily
follow
> > > > > > > > > an
> > > > > > > > > action
> > > > > > > > > through to conclusion, and understand what
was done
> > > > > > > > > at
> > > > > > > > > each
> > > > > > > > > step,
> > > > > > > > > what the system got in return and how it
reacted.
> > > > > > > > > And
> > > > > > > > > all
> > > > > > > > > of
> > > > > > > > > these
> > > > > > > > > actions should be clearly inter-related, so
a
> > > > > > > > > single
> > > > > > > > > grep
> > > > > > > > > can
> > > > > > > > > select
> > > > > > > > > a flow.
> > > > > > > > >
> > > > > > > > > If you prefer to go in the other direction,
like
> > > > > > > > > turning
> > > > > > > > > everything
> > > > > > > > > into a task, that can also work, but each
task,
> > > > > > > > > when
> > > > > > > > > spawning
> > > > > > > > > another, should very clearly show the
relation as
> > > > > > > > > well,
> > > > > > > > > and
> > > > > > > > > sets
> > > > > > > > > of
> > > > > > > > > tasks should be marked as sets.
> > > > > > > > >
> > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > A generic debugging scenario
as I see it.
> > > > > > > > > > > >
> > > > > > > > > > > > 1. Something went wrong
> > > > > > > > > > > > 2. You go looking in the
ENGINE log trying to
> > > > > > > > > > > > figure
> > > > > > > > > > > > out
> > > > > > > > > > > > what
> > > > > > > > > > > > happend.
> > > > > > > > > > > > 3. You see that ENGINE got
SomeError.
> > > > > > > > > > >
> > > > > > > > > > > ok, the rest are all downhill.
> > > > > > > > > > >
> > > > > > > > > > > 4. You follow the failure back to
the start of
> > > > > > > > > > > the
> > > > > > > > > > > flow,
> > > > > > > > > > > then
> > > > > > > > > > > go
> > > > > > > > > > > with
> > > > > > > > > > > the flow to the point where the
engine exited
> > > > > > > > > > > to
> > > > > > > > > > > vdsm
> > > > > > > > > > > 5. switch over to vdsm logs, make
sure you have
> > > > > > > > > > > the
> > > > > > > > > > > timing
> > > > > > > > > > > right
> > > > > > > > > > > (with no flow ID that's the
olny orientation
> > > > > > > > > > > after
> > > > > > > > > > > all)
> > > > > > > > > > > 6. find the start of the vdsm-side
flow, follow
> > > > > > > > > > > it
> > > > > > > > > > > to
> > > > > > > > > > > the
> > > > > > > > > > > failure,
> > > > > > > > > > > pray the error makes sense.
> > > > > > > > > > >
> > > > > > > > > > > In many cases the answer is not in
the vdsm
> > > > > > > > > > > failure
> > > > > > > > > > > traceback
> > > > > > > > > > > but
> > > > > > > > > > > somewhere in the middle of the
flow, with no
> > > > > > > > > > > errors
> > > > > > > > > > > reported,
> > > > > > > > > > > this
> > > > > > > > > > > is why we need a way to easily
follow things
> > > > > > > > > > > through.
> > > > > > > > > > > Moreover,
> > > > > > > > > > > the
> > > > > > > > > > > logs should be readable enough to
make sense to
> > > > > > > > > > > a
> > > > > > > > > > > typical
> > > > > > > > > > > sysadmin,
> > > > > > > > > > > and not a RHEV expert.
> > > > > > > > > > >
> > > > > > > > > > > > 4. Check to see if this error
makes sense
> > > > > > > > > > > > imagining
> > > > > > > > > > > > that
> > > > > > > > > > > > VDSM
> > > > > > > > > > > > is
> > > > > > > > > > > > always right and is a black
box.
> > > > > > > > > > > > 5. You did your digging and
now you think
> > > > > > > > > > > > that
> > > > > > > > > > > > VDSM
> > > > > > > > > > > > is
> > > > > > > > > > > > as
> > > > > > > > > > > > fault.
> > > > > > > > > > > > 6. Go look for the call that
failed. (If we
> > > > > > > > > > > > returned
> > > > > > > > > > > > the
> > > > > > > > > > > > taskID
> > > > > > > > > > > > it's
> > > > > > > > > > > > pretty simple to find that
call).
> > > > > > > > > > > > 7. Look around the call to
check VDSM state.
> > > > > > > > > > > > 8. Profit.
> > > > > > > > > > > >
> > > > > > > > > > > > There is never a point where
you want to
> > > > > > > > > > > > follow
> > > > > > > > > > > > a
> > > > > > > > > > > > whole
> > > > > > > > > > > > flow
> > > > > > > > > > > > call
> > > > > > > > > > > > by
> > > > > > > > > > > > call going back and forth,
and even if you
> > > > > > > > > > > > did
> > > > > > > > > > > > having
> > > > > > > > > > > > the
> > > > > > > > > > > > VDSM
> > > > > > > > > > > > taskID is a better anchor
then flowID.
> > > > > > > > > > >
> > > > > > > > > > > not everything is a task, flow IDs
would unify
> > > > > > > > > > > entire
> > > > > > > > > > > flows,
> > > > > > > > > > > and
> > > > > > > > > > > make
> > > > > > > > > > > following them easy.
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > VDSM is built in a way that
every call takes
> > > > > > > > > > > > in
> > > > > > > > > > > > to
> > > > > > > > > > > > account
> > > > > > > > > > > > the
> > > > > > > > > > > > current state only. Debugging
it with an
> > > > > > > > > > > > engine
> > > > > > > > > > > > flow
> > > > > > > > > > > > mindset
> > > > > > > > > > > > is
> > > > > > > > > > > > just
> > > > > > > > > > > > wrong and distracting. I see
it doing more
> > > > > > > > > > > > harm
> > > > > > > > > > > > the
> > > > > > > > > > > > good
> > > > > > > > > > > > by
> > > > > > > > > > > > reinforcing bad debugging
practices.
> > > > > > > > > > >
> > > > > > > > > > > Maybe you're right, though I
can't see how from
> > > > > > > > > > > my
> > > > > > > > > > > experience
> > > > > > > > > > > so
> > > > > > > > > > > far,
> > > > > > > > > > > but following the flows is the
only thing that
> > > > > > > > > > > got
> > > > > > > > > > > cases
> > > > > > > > > > > resolved.
> > > > > > > > > > > Not event IDs making every
possible error, and
> > > > > > > > > > > not
> > > > > > > > > > > task
> > > > > > > > > > > IDs
> > > > > > > > > > > (though
> > > > > > > > > > > these do have their uses) - slow
and meticulous
> > > > > > > > > > > mapping
> > > > > > > > > > > of
> > > > > > > > > > > flows
> > > > > > > > > > > to
> > > > > > > > > > > log records.
> > > > > > > > > > >
> > > > > > > > > > > >
> > > > > > > > > > > > ----- Original Message -----
> > > > > > > > > > > > > From: "Keith
Robertson"
> > > > > > > > > > > > >
<kroberts(a)redhat.com>
> > > > > > > > > > > > > To: "VDSM Project
Development"
> > > > > > > > > > > > >
<vdsm-devel(a)lists.fedorahosted.org>
> > > > > > > > > > > > > Sent: Thursday, February
9, 2012 1:34:43 PM
> > > > > > > > > > > > > Subject: Re: [vdsm]
flowID schema
> > > > > > > > > > > > >
> > > > > > > > > > > > > On 02/09/2012 12:18 PM,
Andrew Cathrow
> > > > > > > > > > > > > wrote:
> > > > > > > > > > > > > >
> > > > > > > > > > > > > > ----- Original
Message -----
> > > > > > > > > > > > > >> From:
"Ayal Baron"<abaron(a)redhat.com>
> > > > > > > > > > > > > >> To: "Dan
Kenigsberg"<danken(a)redhat.com>
> > > > > > > > > > > > > >> Cc: "VDSM
Project
> > > > > > > > > > > > > >>
Development"<vdsm-devel(a)lists.fedorahosted.org>
> > > > > > > > > > > > > >> Sent: Monday,
February 6, 2012 10:35:54
> > > > > > > > > > > > > >> AM
> > > > > > > > > > > > > >> Subject: Re:
[vdsm] flowID schema
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >> ----- Original
Message -----
> > > > > > > > > > > > > >>> On Thu, Feb
02, 2012 at 10:32:49AM
> > > > > > > > > > > > > >>> -0500,
> > > > > > > > > > > > > >>> Saggi
> > > > > > > > > > > > > >>> Mizrahi
> > > > > > > > > > > > > >>> wrote:
> > > > > > > > > > > > > >>>> flowID
makes no sense after the
> > > > > > > > > > > > > >>>>
initial
> > > > > > > > > > > > > >>>> API
> > > > > > > > > > > > > >>>> call
> > > > > > > > > > > > > >>>> as
> > > > > > > > > > > > > >>>> stuff
> > > > > > > > > > > > > >>>> like
> > > > > > > > > > > > > >>>>
cacheing\threadpools\samplingtasks\resources\asyncTasks
> > > > > > > > > > > > > >>>> so
> > > > > > > > > > > > > >>>>
flowing
> > > > > > > > > > > > > >>>> a flow
like that will not give you the
> > > > > > > > > > > > > >>>> entire
> > > > > > > > > > > > > >>>>
picture
> > > > > > > > > > > > > >>>> while
> > > > > > > > > > > > > >>>>
debugging.
> > > > > > > > > > > > > >>>>
> > > > > > > > > > > > > >>>> Also
adding it now will make
> > > > > > > > > > > > > >>>>
everything
> > > > > > > > > > > > > >>>> even
> > > > > > > > > > > > > >>>> more
> > > > > > > > > > > > > >>>> ugly.
> > > > > > > > > > > > > >>>> You
know what, just imagine I wrote
> > > > > > > > > > > > > >>>> one
> > > > > > > > > > > > > >>>> of
> > > > > > > > > > > > > >>>> my
> > > > > > > > > > > > > >>>> long
> > > > > > > > > > > > > >>>>
rambles
> > > > > > > > > > > > > >>>> about
> > > > > > > > > > > > > >>>> why I
don't agree with doing this.
> > > > > > > > > > > > > >>> I cannot
imagine you write anything
> > > > > > > > > > > > > >>> like
> > > > > > > > > > > > > >>> that.
> > > > > > > > > > > > > >>> Really.
> > > > > > > > > > > > > >>> I
> > > > > > > > > > > > > >>> do
> > > > > > > > > > > > > >>> not
> > > > > > > > > > > > > >>> understand
why you object logging
> > > > > > > > > > > > > >>> flowID
> > > > > > > > > > > > > >>> on
> > > > > > > > > > > > > >>> API
> > > > > > > > > > > > > >>> entry
> > > > > > > > > > > > > >>> point.
> > > > > > > > > > > > > >> The question
is, what problem is this
> > > > > > > > > > > > > >> really
> > > > > > > > > > > > > >> trying
> > > > > > > > > > > > > >> to
> > > > > > > > > > > > > >> solve
> > > > > > > > > > > > > >> and
> > > > > > > > > > > > > >> is
> > > > > > > > > > > > > >> there a simpler
and less obtrusive
> > > > > > > > > > > > > >> solution
> > > > > > > > > > > > > >> to
> > > > > > > > > > > > > >> that
> > > > > > > > > > > > > >> problem?
> > > > > > > > > > > > > > correlating logs
between ovirt engine and
> > > > > > > > > > > > > > potentially
> > > > > > > > > > > > > > multiple
> > > > > > > > > > > > > > vdsm
> > > > > > > > > > > > > > nodes is a
nightmare. It requires a lot
> > > > > > > > > > > > > > skill
> > > > > > > > > > > > > > to
> > > > > > > > > > > > > > follow
> > > > > > > > > > > > > > a
> > > > > > > > > > > > > > transaction through
from the front end
> > > > > > > > > > > > > > all
> > > > > > > > > > > > > > the
> > > > > > > > > > > > > > way
> > > > > > > > > > > > > > to
> > > > > > > > > > > > > > the
> > > > > > > > > > > > > > node,
> > > > > > > > > > > > > > and even multiple
nodes (eg actions on
> > > > > > > > > > > > > > spm,
> > > > > > > > > > > > > > then
> > > > > > > > > > > > > > actions
> > > > > > > > > > > > > > on
> > > > > > > > > > > > > > other
> > > > > > > > > > > > > > node to run a vm).
> > > > > > > > > > > > > > Having a way to
correlate the logs and
> > > > > > > > > > > > > > follow
> > > > > > > > > > > > > > a
> > > > > > > > > > > > > > single
> > > > > > > > > > > > > > event/flow
> > > > > > > > > > > > > > is vital.
> > > > > > > > > > > > > >
> > > > > > > > > > > > > +1
> > > > > > > > > > > > >
> > > > > > > > > > > > > Knowing what command
caused a sequence of
> > > > > > > > > > > > > events
> > > > > > > > > > > > > in
> > > > > > > > > > > > > VDSM
> > > > > > > > > > > > > would
> > > > > > > > > > > > > be
> > > > > > > > > > > > > really
> > > > > > > > > > > > > helpful particularly in
a threaded
> > > > > > > > > > > > > environment.
> > > > > > > > > > > > > Further,
> > > > > > > > > > > > > wouldn't
> > > > > > > > > > > > > such
> > > > > > > > > > > > > an ID be helpful in an
asynchronous
> > > > > > > > > > > > > request/response
> > > > > > > > > > > > > model?
> > > > > > > > > > > > > I'm
> > > > > > > > > > > > > not
> > > > > > > > > > > > > sure what the plans are
for AMQP or even if
> > > > > > > > > > > > > there
> > > > > > > > > > > > > are
> > > > > > > > > > > > > plans,
> > > > > > > > > > > > > but
> > > > > > > > > > > > > I'd
> > > > > > > > > > > > > think that something
like this would be
> > > > > > > > > > > > > crucial
> > > > > > > > > > > > > for
> > > > > > > > > > > > > an
> > > > > > > > > > > > > async
> > > > > > > > > > > > > response.
> > > > > > > > > > > > > So, if you implemented
it you might be
> > > > > > > > > > > > > killing
> > > > > > > > > > > > > 2
> > > > > > > > > > > > > birds
> > > > > > > > > > > > > with
> > > > > > > > > > > > > 1
> > > > > > > > > > > > > stone.
> > > > > > > > > > > > >
> > > > > > > > > > > > > FYI: If you want to see
examples of other
> > > > > > > > > > > > > systems
> > > > > > > > > > > > > that
> > > > > > > > > > > > > use
> > > > > > > > > > > > > similar
> > > > > > > > > > > > > concepts, take a look at
the correlation ID
> > > > > > > > > > > > > in
> > > > > > > > > > > > > JMS.
> > > > > > > > > > > > >
> > > > > > > > > > > > > Cheers,
> > > > > > > > > > > > > Keith
> > > > > > > > > > > > >
> > > > > > > > > > > > >
> > > > > > > > > > > > > >>>
_______________________________________________
> > > > > > > > > > > > > >>> vdsm-devel
mailing list
> > > > > > > > > > > > > >>>
vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > > > > > > >>>
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > > > > >>>
> > > > > > > > > > > > > >>
_______________________________________________
> > > > > > > > > > > > > >> vdsm-devel
mailing list
> > > > > > > > > > > > > >>
vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > > > > > > >>
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > > > > >>
> > > > > > > > > > > > > >
_______________________________________________
> > > > > > > > > > > > > > vdsm-devel mailing
list
> > > > > > > > > > > > > >
vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > > > > > > >
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > > > >
> > > > > > > > > > > > >
_______________________________________________
> > > > > > > > > > > > > vdsm-devel mailing list
> > > > > > > > > > > > >
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> > > > > > > > > > > > >
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > > > >
> > > > > > > > > > > >
_______________________________________________
> > > > > > > > > > > > vdsm-devel mailing list
> > > > > > > > > > > >
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> > > > > > > > > > > >
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > --
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > >
> > > > > > > > > > > Regards,
> > > > > > > > > > >
> > > > > > > > > > > Dan Yasny
> > > > > > > > > > > Red Hat Israel
> > > > > > > > > > > +972 9769 2280
> > > > > > > > > > >
_______________________________________________
> > > > > > > > > > > vdsm-devel mailing list
> > > > > > > > > > > vdsm-devel(a)lists.fedorahosted.org
> > > > > > > > > > >
https://fedorahosted.org/mailman/listinfo/vdsm-devel
> > > > > > > > > > >
> > > > > > > > > >
> > > > > > > > >
> > > > > > > > > --
> > > > > > > > >
> > > > > > > > >
> > > > > > > > >
> > > > > > > > > Regards,
> > > > > > > > >
> > > > > > > > > Dan Yasny
> > > > > > > > > Red Hat Israel
> > > > > > > > > +972 9769 2280
> > > > > > > > >
> > > > > > > >
> > > > > > >
> > > > > > > --
> > > > > > >
> > > > > > >
> > > > > > >
> > > > > > > Regards,
> > > > > > >
> > > > > > > Dan Yasny
> > > > > > > Red Hat Israel
> > > > > > > +972 9769 2280
> > > > > > >
> > > > > >
> > > > >
> > > > > --
> > > > >
> > > > >
> > > > >
> > > > > Regards,
> > > > >
> > > > > Dan Yasny
> > > > > Red Hat Israel
> > > > > +972 9769 2280
> > > > >
> > > >
> > >
> >
>