[gpfsug-discuss] gpfsug-discuss Digest, Vol 108, Issue 18

[Owen Morgan]

Jonathan,

If I have a single policy file with all the related department rules and each time they want to add additional rules with different working day thresholds maybe using this -M method is easier. Its clear that the 'maths' and date/timestamp manipulation is easier in shell (my preferred is bash) than in the SQL of the policy (your example is succinct but needs to be repeated everytime a new rule is added with a different working day threshold, which is what I'm trying (if possiblr) to avoid.

It seems to me the IBM SQL engine is perhaps missing more 'SQL' in built date/time functions like DateAdd and DateDiff etc..  as this would be a moot point. Its a shame I can't make one function that given a working day input as an argument spits out how many 'real' days exist between them for the file age comparison all in the SQL. It can be done for 1 specific input argument, but needs the whole function repeated manually for a different input argument, and further repeated for a different argument etc..

Maybe I'm also compounding the issue by trying to make the policy file as concise as possible (for sake of clarity as to what the rules are trying to achieve, and easy expandability), and demanding too much of the SQL-like syntax that IBM have created.

I have options for mmfind or even (as suggested) -M inoput to mmapplypolicy where I us bash to create a small function that does what I need, spits out 'real days' given a working day input, and using arrays and for-loop create a dynamic calling of the mmapplypolicy command (which I'm kinda half doing anyways for other reasons in my launcher script.


As always, I'm seriously amazed at people with soo much experience and knowledge taking time out to help, guide, and offer input like everyone has been doing!! I'm relatively early in my career, so being able to interact and learn from experienced persons is giving me such a wider insight!

Thanks!

Owen.
[Sent from Front]
On 1 February 2021, 20:17 GMT jonathan.buzzard at strath.ac.uk<mailto:jonathan.buzzard at strath.ac.uk> wrote:

On 01/02/2021 18:11, Jan-Frode Myklebust wrote:

> CAUTION: This email originated outside the University. Check before
> clicking links or attachments.
> Agree.. Write a policy that takes a "mmapplypolicy -M var=val" argument,
> and figure out the workdays outside of the policy. Something like:
>
> # cat test.poilcy
> define( access_age,     (DAYS(CURRENT_TIMESTAMP) - DAYS(ACCESS_TIME)))
> /* list migrated files */
> RULE EXTERNAL LIST 'oldFiles' EXEC ''
> RULE 'oldFiles' LIST 'oldFiles'
>     WHERE (access_age > MINAGE)
>
> # mmapplypolicy gpfs01  -P test.policy -I defer -f ./filelist -M MINAGE=5
>

Why bother when you can do it all in the policy?

JAB.

--
Jonathan A. Buzzard Tel: +44141-5483420
HPC System Administrator, ARCHIE-WeSt.
University of Strathclyde, John Anderson Building, Glasgow. G4 0NG


Owen Morgan
Data Wrangler
Motion Picture Solutions Ltd
T: 
E: owen.morgan at motionpicturesolutions.com | W: motionpicturesolutions.com
A: Mission Hall, 9-11 North End Road, London, W14 8ST
Motion Picture Solutions Ltd is a company registered in England and Wales under number 5388229, VAT number 201330482
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