On 2015-10-31 04:08:06 +0000, David Froble said:
> IanD wrote:
>> Dam it. My previous post missed the comment of which I was replying to
>>
>> Also a few typos; meh...
>>
>> I still maintain VMS clusters are nice but what advantage do they hold
>> over other linux clusters (apart from more stability)
Some of these include (reliable) host-based Volume Shadowing (HBVS)
integrated software RAID-1, and — this is a plus and sometimes a minus
— file locking enabled by default, and online volume expansion.
Biggest liability to these discussions is that these aren't features
that end-users usually buy into. It's the ISVs that have to want and
to use these (and other) features.
> Could not answer this, as I have no knowledge of any clustering
> capabilities on anything other than VMS. I've read that IBM has
> something similar, Sysplex, or something like that.
If you're interested in one of the approaches for operating a large
number of systems, see the Apache tools; Hadoop, Mesos, Kafka,
Zookeeper, etc.
There are other approaches and other sets of tools.
> However, Stephen Hoffman recently mentioned something about someone
> using a file for locking a resource. Now, that's totally unacceptable,
> as far as I'm concerned, but I'm sure there are those who will accept
> the practice.
OpenVMS doesn't have a way to use DLM system-wide without privileges;
noth without something somewhere granting SYSLCK.
On some other systems, a developer can digitally sign — a security
mechanism that OpenVMS isn't even remotely good at — an application
bundle — a concept that OpenVMS completely lacks — and part of that
signing and provisioning process also provides coordinated access to
system-wide mechanisms — which is again an approach that OpenVMS lacks.
OpenVMS security was state-of-the-art back in the 1990s. In this era,
consider how many of us could have compromised zip and unzip images
installed in our systems, secondary to some security breach at one of
the main distribution sites? PCSI utterly insanely lacks a way to
audit and verify what's installed, for that matter. One add-on cert
blows away the whole PCSI signing process, too — y'all do know how to
verify you don't have a rogue cert, right?
Why can't an application or an application bundle have its own
system-wide coordination via DLM? Is the old model of isolating stuff
by UICs and groups model really that useful, for that matter? UICs
and groups really aren't all that flexible, even years ago — ACLs were
in response to these limitations.
>> The other clusters are catching and in some instances gone past VMS
>
> Don't know. As for shared everything, I've read that others don't
> agree with this concept, so how could they "go past" VMS?
Usually by having far larger configurations available and operational,
for starters.
>
>> I still think cheap grid computing back-boned off a VMS cluster might
>> win some future sales
>
> Not sure what this might be, but, not all holes are round, and not all
> pegs are square. Not every application needs what VMS clustering
> provides.
Quite true. Conversely, whether the OpenVMS applications and designs
using what OpenVMS clustering provides might also be deployed in other
clusters, too.
>> Having a system that can spin off a sort/cluster for example means you
>> use all the systems in your cluster
>>
>> Having a cluster present it's as a single large system means you can
>> use all of your cluster versus having around for redundancy
>
> I do believe that in a VMS cluster, all systems can be used, none are
> waiting around for others to fail, so no idle systems for redundancy.
> Not saying VMS clusters don't provide redundancy, just saying they
> don't have systems idle and waiting to be needed.
More than a few folks with clusters do use hosts as a sort of warm
standby. This because distributing the activity over the hosts
involved can spin up the DLM and that can end up leading to
host-to-host lock traffic. That can involve links with more latency
or less bandwidth than might be desired, too. There are also
applications which aren't themselves clustered, but are using HBVS or
other features.
>> As I said in another post, just what market is VMS going to target? No
>> vision means no goals, no goals means going nowhere
>
> This is a concept that can be rather hard. When you provide a general
> purpose widget, it's not your job to "target" markets. It's the users
> who decide your widget can help them. Yes, if you are aware of
> potential uses, you can market to that usage, but, targeting specific
> markets sounds too much like limiting yourself to just those markets.
> Goals could be to produce a better widget.
OpenVMS Engineering has long had market segments they have worked with
— more than a few presentations showed these — and where engineering
added features and mechanisms useful for those folks, and reduced
bottlenecks that targeted customers were encountering. This is both a
very great strategy, and an utterly awful strategy. It's great for
the sorts of things that customers have seen and know and tell you
about, and it's awful for developing the sorts of things that customers
don't yet know they want — once they see or use those new features,
then they do want them. This strategy gets you incremental and
evolutionary changes, and far fewer revolutionary changes. The latter
are the sorts of features that tend to attract new applications and new
vendors.
>> I work in a fairly large IT company that is headquartered in the part
>> of the world that see's lots of IT outsourcing
>
> Maybe it's just me, but my opinion is that sometimes that doesn't work
> too well.
There's no panacea. I've seen competent outsourcing work well, and
I've seen insourcing work well, and I've seen both approaches fail
miserably. It's all in how it's managed and funded and monitored.
Biggest issue with outsourcing: the vendors usually won't fight with
the customer, when the customer is doing something stupid. This is the
flip side of the "the customer is always right" mantra. Sometimes the
customer is being an utter idiot. If a manager or a leader have good
staffers, they'll tell you you're being an idiot. Leaders that
surround themselves with sycophants hopefully have their personal exit
strategies completed before the organization imploded. (Outsourcing
your sycophants is cheaper than paying for in-house ones, too.)
> ...
> What's wrong with supporting the current VMS users. They are sort of
> captive, since anybody that could easily get off VMS left long ago.
> Pretty reliable customers, huh?
It's an inherently-declining market.
> ...
> VSI needs to start somewhere, and the current customer base is their
> best choice. If they get things more up to date, then VMS will sink or
> swim on it's own merits. If somebody really needs it, and is for
> example a Microsoft or Linux bigot, and their application fails, then
> they get fired, and perhaps VMS gets a chance. Or perhaps not. But,
> regardless, at this time, the x86 port isn't everything, it's the ONLY
> thing. [1]
And it may well not be enough.
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