Hi, yes Jackrabbit can handle those numbers. however note the current version of Jackrabbit cannot shard data onto different machines. so this might eventually become an issue.
the other point is that JCR expects much different access patterns than an RDBMS. most people starting off with JCR end up with a content structure that queries too many SQL2 queries rather than path/uuid lookups. the final note is that there arent that many people providing jackrabbit consulting and most of the core contributors focus their support and documentation efforts on CMS products they are working on. regards, Lukas > On 14.11.2013, at 17:51, Ron Wheeler <[email protected]> wrote: > > Remember that Jackrabbit is a free, open source project and you are talking > to other users, not sales or support people. > If you want a consultant who will analyze your requirements and give you a > professional opinion, you have to hire one. > Here, you are getting other users who can share their experience. > You have to decide if their situation and results apply to your situation. > > Ron > >> On 14/11/2013 11:21 AM, Tarun Dogra wrote: >> Hi Enrique, >> >> Thanks for the detailed reply. Unfortunately, I am not familiarised with the >> nodes and the BTree side of Jackrabbit framework. So I was expecting an >> answer in terms of the overall picture of how Jackrabbit as a JCR will fit >> in to our system. >> >> In brief, we need to integrate Jackrabbit (as advised by our vendor) in to >> our clinical trial management system. For this, I have already provided you >> with the server specification on which the system will be hosted. So just >> wanted to know if on such server, Jackrabbit is capable enough to intake >> approximately 15GB data per year and be able to manage those many >> documents/files (as mentioned before) without being affected in terms of its >> performance? We already know it is a much stabilised JCR, but we just wanted >> to confirm if such system is able to suffice our organisation’s requirements. >> >> Regards, >> Tarun >> >> >> From: Enrique Medina Montenegro [mailto:[email protected]] >> Sent: 14 November 2013 14:29 >> To: [email protected]<mailto:[email protected]> >> Cc: Mark Essex >> Subject: Re: Jackrabbits reliability and performance >> >> Hi Tarun, >> >> Let me share my findings with you :-) >> >> At my work we are evaluating the use of Jackrabbit to build a JCR repository >> to store the register of marks (intellectual property) as documents composed >> basically of an ID, some metadata (who created it, when, etc.) and the XML >> and JSON representation of the mark itself. Currently, we have all that >> information spread in several relational DBs and we would like to take >> advantage of the versioning and observation features of the JCR repository. >> >> During our initial evaluation, mostly focused on performance, we noticed >> serious issues when adding the 1 million marks we have currently in our DBs >> underneath the same "parent" node, but we found out that this was actually a >> known limitation by Jackrabbit, which clearly states that no more than 10K >> child nodes should be added to the same "parent "node: >> >> http://wiki.apache.org/jackrabbit/Performance >> >> However, we were still sort of forced to follow that path because we were >> required to perform an initial dump of all the data in the DBs, and just >> adding each mark as a sub-mode proved to be the fastest way to export all >> the data in an acceptable window frame. >> >> Nevertheless, we also tried to shard the nodes as a tree, basically >> splitting the 9-digit ID of our marks into 3-digit groups, so each node >> could only have as much as 1K sub-nodes within itself. For example, mark >> with ID = 000342865 would be saved into --> root (node) -> marks (node) -> >> 000 (node) -> 342 (node) --> 000342865 (node). Theoretically, this would >> perform much better than our original approach, but as a downside, it would >> dramatically slow down the time it takes to export the 1M marks from the >> DBs, going further out of our acceptable window frame (due to the fact that, >> for each mark, it had to previously look up the exact node where to store >> it, and the bigger the JCR repository was growing, the slower the node >> lookup times were, therefore impacting the overall export process). >> >> We also took a look at the BTreeManager, but we just couldn't make it work >> due to the issue I describe here (which BTW has not been answered yet): >> >> http://mail-archives.apache.org/mod_mbox/jackrabbit-users/201311.mbox/ajax/%3CCA%2BdeSP_weUQ0mtSBjoQGy3jq60jZEo7LtmF9kJZkvF1eyNvu-A%40mail.gmail.com%3E >> >> So getting back to the original approach of storing everything under the >> same node, how did we manage to get acceptable read times? Well, it boils >> down to using Lucene's indexation (configured properly to only index the >> "id" property, and not all the XML and JSON stuff - using the >> IndexingConfiguration in the Search section of the repository config file) >> to actually perform the search/retrieval of marks. So for instance, instead >> of: >> >> session.getNode("/marks/000342865") --> takes ~2.4segs with 1M marks under >> the same node >> >> we run this query with SQL2: >> >> SELECT * FROM markType WHERE id = '000342865' --> takes tens of ms with 1M >> marks under the same node thanks to Lucene's indexes >> >> (notice that "markType" is a custom node type that we have created to model >> our domain, in this case the marks) >> >> LESSONS LEARNED: You need to clearly define the scope of your project in >> terms of the functionality you're willing to use from Jackrabbit, and then >> plan for detailed performance workshops to prove your approach. There are >> always trade-offs (for instance, in my case, when I want to get the specific >> version of a mark, I cannot use the "official" API through "VersionManager" >> because it uses direct path to fetch the node prior to getting the revision >> --> >> session.getWorkspace().getVersionManager().getVersionHistory("/marks/000342865").getVersionByLabel("v.6.0"), >> and I have to use the "deprecated" API method from the node itself, once >> I've got it using the SQL2 statement mentioned above --> >> markNode.getVersionHistory().getVersionByLabel("v.6.0"), with the >> uncertainty on when that deprecated API will be removed...). >> >> Please share your findings in the list as you make progress :-) >> >> Regards, >> Enrique Medina. >> >> On Thu, Nov 14, 2013 at 10:40 AM, Tarun Dogra >> <[email protected]<mailto:[email protected]>> wrote: >> Respected Sir/Madam, >> >> In the next couple of months, we (ORION Clinical Services Ltd., UK) are >> about to release a clinical trial management system as a product to be used >> in-house by all our employees. We have bought this product off the shelf >> from a third party vendor. As suggested by our vendor, we would implement >> JackRabbit as the central repository system within this main product. But we >> are still not sure whether jackrabbit is an ideal solution to be integrated >> with our product and this is where we will need your help and would >> appreciate if you could share your expertise. >> >> Just to give you an overview of our organisation, we will have around 7500 >> documents (each of size 250K approximately on an average) per "study" within >> our clinical trial management framework. We usually take on board around >> 7-8 such studies per year. So, on the basis of 8 studies per year, the total >> size of all the documents will grow to 7500 x 250 x 8 = 15GB approximately >> per year. So just wanted to know a couple of things from you: >> >> 1. Is Jackrabbit reliable enough as a system to cater to our above >> mentioned needs? and >> >> 2. Will the management of so many documents have any adverse effects >> on jackrabbit's performance? - considering that Jackrabbit will reside on >> one of our own hosted server with the following spec - >> >> Poweredge R710 >> >> CPU: 2 x Intel X5550 >> >> Memory: 16GB >> >> Operating System: Windows 2008 R2 64bit SP1 >> >> Disk capacity: C: 142gb and D: 1.22Tb >> >> >> Sorry if you are not the correct department to consult to in regards to our >> above mentioned concern and if this is the case, it will be much appreciated >> if you could direct us to the right department/person? Many thanks. >> >> Look forward to hearing from you. >> >> Regards, >> Tarun > > > -- > Ron Wheeler > President > Artifact Software Inc > email: [email protected] > skype: ronaldmwheeler > phone: 866-970-2435, ext 102 >
