Dear John, Most sound institutional data repositories use some form of off-site backup. However, not all of them do, and the standards of reliabilty vary. The advantages of an explicit partnering system are both practical and psychological. The practical part is the major improvement in reliability -- even if we start at 6 nines, 12 nines is better. The psychological part is that members of the community can feel reassured that reliability has in been improved to levels at which they can focus on other, more scientific issues, instead ot the question of reliability.
Regards,
Herbert
=====================================================
Herbert J. Bernstein, Professor of Computer Science
Dowling College, Kramer Science Center, KSC 121
Idle Hour Blvd, Oakdale, NY, 11769
+1-631-244-3035
y...@dowling.edu
=====================================================
On Sat, 29 Oct 2011, Jrh wrote:
Dear Herbert, I imagine it likely that eg The Univ Manchester eScholar system will have in place duplicate storage for the reasons you outline below. However for it to be geographically distant is, to my reckoning, less likely, but still possible. I will add that further query to my first query to my eScholar user support re dataset sizes and doi registration. Greetings, John Prof John R Helliwell DSc On 29 Oct 2011, at 15:49, "Herbert J. Bernstein" <y...@bernstein-plus-sons.com> wrote:One important issue to address is how deal with the perceived reliability issues of the federated model and how to start to approach the higher reliability of the centralized model described bu Gerard K, but without incurring what seems to be at present unacceptable costs. One answer comes from the approach followed in communications systems. If the probability of data loss in each communication subsystem is, say, 1/1000, then the probability of data loss in two independent copies of the same lossy system is only 1/1,000,000. We could apply that lesson to the federated data image archive model by asking each institution to partner with a second independent, and hopefully geographically distant, institution, with an agreement for each to host copies of the other's images. If we restrict that duplication protocol, at least at first, to those images strongly related to an actual publication/PDB deposition, the incremental cost of greatly improved reliability would be very low, with no disruption of the basic federated approach being suggested. Please note that I am not suggesting that institutional repositories will have 1/1000 data loss rates, but they will certainly have some data loss rate, and this modest change in the proposal would help to greatly lower the impact of that data loss rate and allow us to go forward with greater confidence. Regards, Herbert At 7:53 AM +0100 10/29/11, Jrh wrote:Dear Gerard K, Many thanks indeed for this. Like Gerard Bricogne you also indicate that the location option being the decentralised one is 'quite simple and very cheap in terms of centralised cost'. The SR Facilities worldwide I hope can surely follow the lead taken by Diamond Light Source and PaN, the European Consortium of SR and Neutron Facilities, and keep their data archives and also assist authors with the doi registration process for those datasets that result in publication. Linking to these dois from the PDB for example is as you confirm straightforward. Gerard B's pressing of the above approach via the 'Pilot project' within the IUCr DDD WG various discussions, with a nicely detailed plan, brought home to me the merit of the above approach for the even greater challenge for raw data archiving for chemical crystallography, both in terms of number of datasets and also the SR Facilities role being much smaller. IUCr Journals also note the challenge of moving large quantities of data around ie if the Journals were to try and host everything for chemical crystallography, and them thus becoming 'the centre' for these datasets. So:- Universities are now establishing their own institutional repositories, driven largely by Open Access demands of funders. For these to host raw datasets that underpin publications is a reasonable role in my view and indeed they already have this category in the University of Manchester eScholar system, for example. I am set to explore locally here whether they would accommodate all our Lab's raw Xray images datasets per annum that underpin our published crystal structures. It would be helpful if readers of this CCP4bb could kindly also explore with their own universities if they have such an institutional repository and if raw data sets could be accommodated. Please do email me off list with this information if you prefer but within the CCP4bb is also good. Such an approach involving institutional repositories would also work of course for the 25% of MX structures that are for non SR datasets. All the best for a splendid PDB40 Event. Greetings, John Prof John R Helliwell DSc On 28 Oct 2011, at 22:02, Gerard DVD Kleywegt <ger...@xray.bmc.uu.se> wrote:Hi all, It appears that during my time here at Cold Spring Harbor, I have missed a small debate on CCP4BB (in which my name has been used in vain to boot). I have not yet had time to read all the contributions, but would like to make a few points that hopefully contribute to the discussion and keep it with two feet on Earth (as opposed to La La Land where the people live who think that image archiving can be done on a shoestring budget... more about this in a bit). Note: all of this is on personal title, i.e. not official wwPDB gospel. Oh, and sorry for the new subject line, but this way I can track the replies more easily. It seems to me that there are a number of issues that need to be separated: (1) the case for/against storing raw data (2) implementation and resources (3) funding (4) location I will say a few things about each of these issues in turn: ----------- (1) Arguments in favour and against the concept of storing raw image data, as well as possible alternative solutions that could address some of the issues at lower cost or complexity. I realise that my views carry a weight=1.0 just like everybody else's, and many of the arguments and counter-arguments have already been made, so I will not add to these at this stage. ----------- (2) Implementation details and required resources. If the community should decide that archiving raw data would be scientifically useful, then it has to decide how best to do it. This will determine the level of resources required to do it. Questions include: - what should be archived? (See Jim H's list from (a) to (z) or so.) An initial plan would perhaps aim for the images associated with the data used in the final refinement of deposited structures. - how much data are we talking about per dataset/structure/year? - should it be stored close to the source (i.e., responsibility and costs for depositors or synchrotrons) or centrally (i.e., costs for some central resource)? If it is going to be stored centrally, the cost will be substantial. For example, at the EBI -the European Bioinformatics Institute- we have 15 PB of storage. We pay about 1500 GBP (~2300 USD) per TB of storage (not the kind you buy at Dixons or Radio Shack, obviously). For stored data, we have a data-duplication factor of ~8, i.e. every file is stored 8 times (at three data centres, plus back-ups, plus a data-duplication centre, plus unreleased versus public versions of the archive). (Note - this is only for the EBI/PDBe! RCSB and PDBj will have to acquire storage as well.) Moreover, disks have to be housed in a building (not free!), with cooling, security measures, security staff, maintenance staff, electricity (substantial cost!), rental of a 1-10 Gb/s connection, etc. All hardware has a life-cycle of three ye!
ars (barring failures) and then needs to be replaced (at lower cost, but still not free).
- if the data is going to be stored centrally, how will it get there? Using ftp will probably not be feasible. - if it is not stored centrally, how will long-term data availability be enforced? (Otherwise I could have my data on a public server until my paper comes out in print, and then remove it.) - what level of annotation will be required? There is no point in having zillions of files lying around if you don't know which structure/crystal/sample they belong to, at what wavelength they were recorded, if they were used in refinement or not, etc. - an issue that has not been raised yet, I think: who is going to validate that the images actually correspond to the structure factor amplitudes or intensities that were used in the refinement? This means that the data will have to be indexed, integrated, scaled, merged, etc. and finally compared to the deposited Fobs or Iobs. This will have to be done for *10,000 data sets a year*... And I can already imagine the arguments that will follow between depositors and "re-processors" about what software to use, what resolution cut-off, what outlier-rejection criteria, etc. How will conflicts and discrepancies be resolved? This could well end up taking a day of working time per data set, i.e. with 200 working days per year, one would need 50 *new* staff for this task alone. For comparison: worldwide, there is currently a *total* of ~25 annotators working for the wwPDB partners... Not many of you know that (about 10 years ago) I spent probably an entire year of my life sorting out the mess that was the PDB structure factor files pre-EDS... We were apparently the first people to ever look at the tens of thousands of structure factor files and try to use all of them to calculate maps for the EDS server. (If there were others who attempted this before us, they had probably run away screaming.) This went well for many files, but there were many, many files that had problems. There were dozens of different kinds of issues: non-CIF files, CIF files with wrong headers, Is instead of Fs, Fcalc instead of Fobs, all "h" equal to 0, non-space-separated columns, etc. For a list, see: http://eds.bmc.uu.se/eds/eds_help.html#PROBLEMS Anyway, my point is that simply having images without annotation and without reprocessing is like having a crystallographic kitchen sink (or bit bucket) which will turn out to be 50% useless when the day comes that somebody wants to do archive-wide analysis/reprocessing/rerefinement etc. And if the point is to "catch cheaters" (which in my opinion is one of the weakest, least-fundable arguments for storage), then the whole operation is in fact pointless without reprocessing by a "third party" at deposition time. ----------- (3) Funding. This is one issue we can't really debate - ultimately, it is the funding agencies who have to be convinced that the cost/benefit ratio is low enough. The community will somehow have to come up with a stable, long-term funding model. The outcome of (2) should enable one to estimate the initial investment cost plus the variable cost per year. Funding could be done in different ways: - centrally - e.g., a big application for funding from NIH or EU - by charging depositors (just like they are charged Open Access charges, which can often be reclaimed from the funding agencies) - would you be willing to pay, say, 5000 USD per dataset to secure "perpetual" storage? - by charging users (i.e., Gerard Bricogne :-) - just kidding! Of course, if the consensus is to go for decentralised storage and a DOI-like identifier system, there will be no need for a central archive, and the identifiers could be captured upon deposition in the PDB. (We could also check once a week if the files still exist where they are supposed to be.) ----------- (4) Location. If the consensus is to have decentralised storage, the solution is quite simple and very cheap in terms of "centralised" cost - wwPDB can capture DOI-like identifiers upon deposition and make them searchable. If central storage is needed, then there has to be an institution willing and able to take on this task. The current wwPDB partners are looking at future funding that is at best flat, with increasing numbers of depositions that also get bigger and more complex. There is *no way on earth* that wwPDB can accept raw data (be it X-ray, NMR or EM! this is not an exclusive X-ray issue) without *at least* double the current level of funding (and not just in the US for RCSB, but also in Japan for PDBj and in Europe for PDBe)! I am pretty confident that this is simply *not* going to happen. [Besides, in my own humble opinion, in order to remain relevant (and fundable!) in the biomedical world, the PDB will have to restyle itself as a biomedical resource instead of a crystallographic archive. We must take the structures to the biologists, and we must expand in breadth of coverage to include emerging hybrid methods that are relevant for structural cell (as opposed to molecular) biology. This mission will be much easier to fund on three continents than archiving TBs of raw data that have little or no tangible (i.e., fundable) impact on our quest to find a cure for various kinds of cancer (or hairloss) or to feed a growing population.] However, there may be a more realistic solution. The role model could be NMR, which has its own global resource for data storage in the BMRB. BMRB is a wwPDB partner - if you deposit an NMR model with us, we take your ensemble coordinates, metadata, restraints and chemical shifts - any other NMR data (including spectra and FIDs) can subsequently be deposited with BMRB. These data will get their own BMRB ID which can be linked to the PDB ID. A model like this has advantages - it could be housed in a single place, run by X-ray experts (just as BMRB is co-located with NMRFAM, the national NMR facility at Madison), and there would be only one place that would need to secure the funding (which would be substantially larger than the estimate of $1000 per year suggested by a previous poster from La La Land). This could for instance be a synchrotron (linked to INSTRUCT?), or perhaps one of the emerging nations could be enticed to take on this challenging task. I would expect that such a centre would be closely affiliated with the wwPDB organisation, or become a member just like BMRB. A similar model could also be employed for archiving raw EM image data. ----------- I've said enough for today. It's almost time for the booze-up that kicks off the PDB40 symposium here at CSHL! Heck, some of you who read this might be here as well! Btw - Colin Nave wrote: "(in increasing order of influence/power do we have the Pope, US president, the Bond Market and finally Gerard K?)" I'm a tad disappointed to be only in fourth place, Colin! What has the Pope ever done for crystallography? --Gerard ****************************************************************** Gerard J. Kleywegt http://xray.bmc.uu.se/gerard mailto:ger...@xray.bmc.uu.se ****************************************************************** The opinions in this message are fictional. Any similarity to actual opinions, living or dead, is purely coincidental. ****************************************************************** Little known gastromathematical curiosity: let "z" be the radius and "a" the thickness of a pizza. Then the volume of that pizza is equal to pi*z*z*a ! ******************************************************************-- ===================================================== Herbert J. Bernstein, Professor of Computer Science Dowling College, Brookhaven Campus, B111B 1300 William Floyd Parkway, Shirley, NY, 11967 +1-631-244-1328 Lab: +1-631-244-1935 Cell: +1-631-428-1397 y...@dowling.edu =====================================================
