[cgl_discussion] CGL requirement - checkpointing

Pan, Deng deng.pan at intel.com
Thu Jun 19 20:12:05 PDT 2003


My idea is to implement the data checkpointing based on Linux-HA
Heartbeat project. You know, checkpointing has to depend on the low
level services provided by 
Heartbeat project. It will be served as loadable module of Heartbeat
because some customers may think that stateless failover is enough, as
Peter pointed out.

As for the API compliance, it is my biggest headache. Linux-HA Heartbeat
is the reference implementation of OCF and its API will be OCF
compliant. But currently, OCF has no data checkpointing API published.
But if I implement AIS based on OCF, it is hard to be accepted by the
OCF community. The most optimistic result is I create a new set of data
checkpointing API and publish it as one part of OCF, just throwing AIS
away. Anyway, we can still borrow some ideas from AIS.

For the licensing model, it should be GPL because Linux-HA heartbeat is
GPL.

-----Original Message-----
From: Peter Badovinatz [mailto:tabmowzo at us.ibm.com] 
Sent: 2003-06-20 3:02
To: Pan, Deng
Cc: cgl_discussion at osdl.org
Subject: Re: [cgl_discussion] CGL requirement - checkpointing

"Pan, Deng" wrote:
> 
> Hi, steven:
> In my opinion, the main gap between customer clustering requirement
and
> the existing open source clustering project is the stateful failover,
> because we have already had the stateless failover solution such as
> Linux-HA and FailSafe. Without checkpointing, we can not do the
stateful
> failover and our osdl clutering efforts will be dimmed too much.

Deng,

You're correct that stateful failover is the gap here.  I'll point out
that stateless failover support has a very broad market in itself, so we
shouldn't consider existing OSDL clustering efforts to be as dim as you
imply.  

But as we're talking "Carrier" Grade Linux, then yes, checkpointing is a
key missing element, and we've no current open path to support it.

> 
> Yes, I am considering solving this requirement. Although currently
there
> is no open source project aimed at this requirement, there do have
> several commercial solutions available from SAF members right now.
> Actually, SAF Application Interface Specification was based on those
> solutions :-)

We're well aware of the SAF AIS.  A specification is not an open
implementation though, that and the existence of commercial solutions
leads us to place checkpointing in the "future resolution" category at
this time.  Note that the commercial solutions do not exactly map to SAF
AIS, despite being the inspiration for it.  The specification evolved
away from direct match to any one implementation as it was being
developed.

> 
> I will put more my ideas here later.

We welcome them, as Steve states.

> 
> -----Original Message-----
> From: Steven Dake [mailto:sdake at mvista.com]
> Sent: 2003-06-17 23:30
> To: Pan, Deng
> Cc: cgl_discussion at osdl.org
> Subject: Re: [cgl_discussion] FYI - PoC Tracking Sheets updated
> 
> Deng,
> 
> At the Helsinki F2F, checkpointing and several other cluster
> requirements were moved to be resolved in a future specification.  The
> reasoning was that making it a priority 3 requirement (since no
projects
> 
> exist) would make it seem unvaluable (when it is critical for many
> solutions) and encoding it as priority 1 would require something in
the
> community to use, when no real solutions currently exist.
> 
> If you are involved in solving this requirement or considering a
> project, the PoC would be happy to track that information.  Please let
> me know and I'll get the information added to the tracking sheet.  At
> this time, I know of no projects that are looking at this from an
> application standpoint that are heading towards the requirements set
> forth in the OSDL specs.
> 
> Thanks
> -steve
> 
> Pan, Deng wrote:
> 
> >Checkpointing is the priority 1 requirement of CGL 2.0, but till now,
I
> >can not find any discussion neither in julie's PoC tracking sheet,
nor
> >in andy's CGL project list. Is there anybody looking into this
> >requirement?
> >
> >-----Original Message-----
> >From: Fleischer, Julie N
> >Sent: 2003-06-17 7:54
> >To: cgl_discussion at osdl.org
> >Subject: [cgl_discussion] FYI - PoC Tracking Sheets updated
> >
> >Just thought you might like to know that I have updated the PoC
> tracking
> >sheet on the web with the best data I have so far.  The only area
where
> >there are blanks is in the "carryover, unchanged" requirements.  This
> >should be a simple port from Andy's spreadsheet when we get the time.
> >
> >The file names are:
> >XLS format -
> >http://www.osdl.org/docs/poc_cgl_20_priority_1_solutions.xls
> >PDF format -
> >http://www.osdl.org/docs/cgl_20_p1_project_list___pdf_format.pdf
> >HTML format - attached
> >
> >- Julie

Peter
--
Peter R. Badovinatz aka 'Wombat' -- IBM Linux Technology Center
preferred: tabmowzo at us.ibm.com / alternate: wombat at us.ibm.com
These are my opinions and absolutely not official opinions of IBM, Corp.




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