Re: [Neo4j] java.lang.OutOfMemoryError: PermGen space
messages.log extract available here: http://dl.dropbox.com/u/5216304/20110812-neo4j-messages.log -- Tatham -Original Message- From: user-boun...@lists.neo4j.org [mailto:user-boun...@lists.neo4j.org] On Behalf Of Tatham Oddie Sent: Friday, 12 August 2011 3:57 PM To: Neo4j user discussions (user@lists.neo4j.org) Subject: [Neo4j] java.lang.OutOfMemoryError: PermGen space Howdy, We've started experiencing reasonably consistent java.lang.OutOfMemoryError exceptions. We're using neo4j-community-1.4.M04-windows.zip, running on Windows 7 x64 for development + Windows Azure for production. Graph access is exclusively via REST. We perform basic CRUD operations and Gremlin queries. The server spins up like so: 12/08/11 2:39:43 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Starting Neo Server on port [5102] with [80] threads available 12/08/11 2:39:43 PM org.neo4j.server.database.Database INFO: Using database at C:\AzureTemp\neo4j-db 12/08/11 2:39:47 PM org.neo4j.server.modules.DiscoveryModule INFO: Mounted discovery module at [/] 12/08/11 2:39:48 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin CypherPlugin 12/08/11 2:39:48 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin GremlinPlugin 12/08/11 2:39:48 PM org.neo4j.server.modules.RESTApiModule INFO: Mounted REST API at [/db/data/] 12/08/11 2:39:48 PM org.neo4j.server.modules.ManagementApiModule INFO: Mounted management API at [/db/manage/] 12/08/11 2:39:48 PM org.neo4j.server.modules.WebAdminModule INFO: Mounted webadmin at [/webadmin] 12/08/11 2:39:48 PM org.neo4j.server.web.Jetty6WebServer INFO: Mounting static content at [/webadmin] from [webadmin-html] 12/08/11 2:39:50 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Server started on [http://192.168.10.151:5102/] Then, after a relatively small number of queries (sub 500? still confirming more details), we get this: Exception in thread RMI RenewClean-[192.168.10.151:31174] java.lang.OutOfMemoryError: PermGen space Exception in thread Statistics Gatherer java.lang.OutOfMemoryError: PermGen space Java.exe is still running, and consuming around 180MB of RAM (with another 3GB of physical memory still available on the system). REST API returns 500s and the WebAdmin is unavailable. My questions: 1) Is this just that we've got a configuration setting wrong? In my very limited knowledge of Java, I know we can reconfigure the size, but this seems to indicate a potentially larger issue. 2) What should I do to gather more information to help diagnose this? -- Tatham Oddie au mob: +61 414 275 989, us cell: +1 415 598 8201, skype: tathamoddie If you're printing this email, you're doing it wrong. This is a computer, not a typewriter. ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] java.lang.OutOfMemoryError: PermGen space
please update to 1.4.1 the this goes away and change your gremlin queries to use variables instead of concatenating values into the query string thanks Michael mobile mail please excuse brevity and typos Am 12.08.2011 um 07:56 schrieb Tatham Oddie tat...@oddie.com.au: Howdy, We've started experiencing reasonably consistent java.lang.OutOfMemoryError exceptions. We're using neo4j-community-1.4.M04-windows.zip, running on Windows 7 x64 for development + Windows Azure for production. Graph access is exclusively via REST. We perform basic CRUD operations and Gremlin queries. The server spins up like so: 12/08/11 2:39:43 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Starting Neo Server on port [5102] with [80] threads available 12/08/11 2:39:43 PM org.neo4j.server.database.Database INFO: Using database at C:\AzureTemp\neo4j-db 12/08/11 2:39:47 PM org.neo4j.server.modules.DiscoveryModule INFO: Mounted discovery module at [/] 12/08/11 2:39:48 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin CypherPlugin 12/08/11 2:39:48 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin GremlinPlugin 12/08/11 2:39:48 PM org.neo4j.server.modules.RESTApiModule INFO: Mounted REST API at [/db/data/] 12/08/11 2:39:48 PM org.neo4j.server.modules.ManagementApiModule INFO: Mounted management API at [/db/manage/] 12/08/11 2:39:48 PM org.neo4j.server.modules.WebAdminModule INFO: Mounted webadmin at [/webadmin] 12/08/11 2:39:48 PM org.neo4j.server.web.Jetty6WebServer INFO: Mounting static content at [/webadmin] from [webadmin-html] 12/08/11 2:39:50 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Server started on [http://192.168.10.151:5102/] Then, after a relatively small number of queries (sub 500? still confirming more details), we get this: Exception in thread RMI RenewClean-[192.168.10.151:31174] java.lang.OutOfMemoryError: PermGen space Exception in thread Statistics Gatherer java.lang.OutOfMemoryError: PermGen space Java.exe is still running, and consuming around 180MB of RAM (with another 3GB of physical memory still available on the system). REST API returns 500s and the WebAdmin is unavailable. My questions: 1) Is this just that we've got a configuration setting wrong? In my very limited knowledge of Java, I know we can reconfigure the size, but this seems to indicate a potentially larger issue. 2) What should I do to gather more information to help diagnose this? -- Tatham Oddie au mob: +61 414 275 989, us cell: +1 415 598 8201, skype: tathamoddie If you're printing this email, you're doing it wrong. This is a computer, not a typewriter. ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] Indexing - Rest Api
Hi, I am planning to extend the .Net client that we use for CRUD operation and now add indexing support. I am keen to go the route of AutoIndexing, so we just query the index and it automatically gets create. Just a few questions. * Configuration File: Autoindexing enabled here is related to automatically indexing all nodes and relationships? * If I want to add a node to an index following the guidelines, what convention should be used for the Key/Value naming? Imagine we have nodes of type Customers, and we have 1 customers, what sort of key/value would we set for each customer, as I would guess that all properties are indexed for the node? Would it be perhaps a unique auto increment number for example that is in no way related to the data node? e.g. Example request * POST http://localhost:7474/db/data/index/node/favorites/key/the%20value * Accept: application/json * Content-Type: application/json http://localhost:7474/db/data/node/0 * Also, how can we control the properties/fields to index when we add a node to an index with the RestApi, I would imagine we would not want to index all fields on a node via the auto indexing feature? Our plan is to use Lucene Search Queries so we can do funzzy searches, however, we would like to leverage autoindexing but have the option to choose exactly what fields we want to index on a node when we add nodes to indexes. Thank You. ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] some questions : unique property and Rest
1.Does Neo4J support *unique property* (Node/Relationship)? Right now there is no native support for that, you have to implement it on your own - define the properties that are unique and then write an getOrCreateNode method and/or endpoint that exposes the following things: - query the index for the property - if it returns something return it - open tx - grab write lock on a dedicated lock node (e.g. by removing an non-existing property) - query the index for the property - if it returns something return it - if not create the node and add it to the index - close tx It might be added to Neo4j at a later time in the form of a unique index type (or differently). 2.How can I wrap a Node in a MyClass and using it with Rest services? what do you mean by with rest-services ? If you mean something like object graph mapping in the server - you might the existing language bindings to map objects to the graph using unmanaged extensions (Spring Data Graph, jo4neo) or the (J)ruby-script-extensions (neo4j.rb). 3.Can I use in MyClass some JPA annotaions? So if you want to have some cross-store persistence (graph + JPA) then you should look into Spring Data Graph as this supports that mode explicitely. Cheers Michael shlomib -- View this message in context: http://neo4j-community-discussions.438527.n3.nabble.com/some-questions-unique-property-and-Rest-tp3248352p3248352.html Sent from the Neo4j Community Discussions mailing list archive at Nabble.com. ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] neo4j spatial and postgis
Hi, I very interested in neo4j spatial . but I do not know how to import the spatial data. My data are stored in postgis. I read the document http://wiki.neo4j.org/content/Spatial_Data_Storage; and http://wiki.neo4j.org/content/Importing_and_Exporting_Spatial_Data,but I yet do not know to to import data from postgis or import shapfiles. Could you provide some detail information? Please advice. zhao ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
[Neo4j] Database error
After I installed the base (1.4 community) - I felt it necessary to fill existing data (users of the system and relations between them). Total users about 1.6 million and 4.5 million links. I wrote a robot, using REST-requests and creates the necessary link between the top two. After I ran it and measured the rate of filling databases - according to my calculations, the robot had to work 2-3 days. That suits me and I left it running. But after about 4 hours, when the copy already around 200 000 relations - error occurred and the database is not working. Here's from the log: 8/8/11 3:02:54 PM org.neo4j.server.NeoServerBootstrapper INFO: Neo4j Server shutdown initiated by kill signal Unable to close logical log java.io.FileNotFoundException: /path_to_neo4j/data/graph.db/nioneo_logical.log.active (No such file or directory) at java.io.RandomAccessFile.open(Native Method) at java.io.RandomAccessFile.init(Unknown Source) at java.io.RandomAccessFile.init(Unknown Source) at org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog.setActiveLog(XaLogicalLog.java:1478) at org.neo4j.kernel.impl.transaction.xaframework.XaLogicalLog.close(XaLogicalLog.java:692) at org.neo4j.kernel.impl.transaction.xaframework.XaContainer.close(XaContainer.java:109) at org.neo4j.kernel.impl.nioneo.xa.NeoStoreXaDataSource.close(NeoStoreXaDataSource.java:248) at org.neo4j.kernel.impl.nioneo.xa.NioNeoDbPersistenceSource.stop(NioNeoDbPersistenceSource.java:69) at org.neo4j.kernel.GraphDbInstance.shutdown(GraphDbInstance.java:293) at org.neo4j.kernel.EmbeddedGraphDbImpl.shutdown(EmbeddedGraphDbImpl.java:349) at org.neo4j.kernel.EmbeddedGraphDatabase.shutdown(EmbeddedGraphDatabase.java:125) at org.neo4j.server.database.Database.shutdown(Database.java:111) at org.neo4j.server.NeoServerWithEmbeddedWebServer.stopDatabase(NeoServerWithEmbeddedWebServer.java:275) at org.neo4j.server.NeoServerWithEmbeddedWebServer.stop(NeoServerWithEmbeddedWebServer.java:226) at org.neo4j.server.Bootstrapper$1.run(Bootstrapper.java:157) 8/8/11 3:02:57 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Starting Neo Server on port [7474] with [40] threads available 8/8/11 3:02:57 PM org.neo4j.server.database.Database INFO: Using database at /path_to_neo4j/data/graph.db 8/8/11 3:02:59 PM org.neo4j.server.modules.DiscoveryModule INFO: Mounted discovery module at [/] 8/8/11 3:02:59 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin CypherPlugin 8/8/11 3:02:59 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin GremlinPlugin 8/8/11 3:02:59 PM org.neo4j.server.modules.RESTApiModule INFO: Mounted REST API at [/db/data/] 8/8/11 3:02:59 PM org.neo4j.server.modules.ManagementApiModule INFO: Mounted management API at [/db/manage/] 8/8/11 3:02:59 PM org.neo4j.server.modules.WebAdminModule INFO: Mounted webadmin at [/webadmin] 8/8/11 3:02:59 PM org.neo4j.server.web.Jetty6WebServer INFO: Mounting static content at [/webadmin] from [webadmin-html] 8/8/11 3:03:01 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Server started on [http://our_site:7474/] 8/8/11 3:04:46 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Starting Neo Server on port [7474] with [40] threads available 8/8/11 3:04:46 PM org.neo4j.server.database.Database INFO: Using database at /path_to_neo4j/data/graph.db 8/8/11 3:04:46 PM org.neo4j.server.modules.DiscoveryModule INFO: Mounted discovery module at [/] 8/8/11 3:04:47 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin CypherPlugin 8/8/11 3:04:47 PM org.neo4j.server.plugins.PluginManager INFO: Loaded server plugin GremlinPlugin 8/8/11 3:04:47 PM org.neo4j.server.modules.RESTApiModule INFO: Mounted REST API at [/db/data/] 8/8/11 3:04:47 PM org.neo4j.server.modules.ManagementApiModule INFO: Mounted management API at [/db/manage/] 8/8/11 3:04:47 PM org.neo4j.server.modules.WebAdminModule INFO: Mounted webadmin at [/webadmin] 8/8/11 3:04:47 PM org.neo4j.server.web.Jetty6WebServer INFO: Mounting static content at [/webadmin] from [webadmin-html] 8/8/11 3:04:48 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Server started on [http://our_site:7474/] 8/8/11 3:24:31 PM org.neo4j.server.NeoServerBootstrapper INFO: Neo4j Server shutdown initiated by kill signal 8/8/11 3:24:33 PM org.neo4j.server.NeoServerWithEmbeddedWebServer INFO: Starting Neo Server on port [7474] with [40] threads available etc. - The same errors but after 20 minutes have gone there are errors (strange errors): 8/11/11 1:39:43 AM org.neo4j.server.rrd.ScheduledJob WARNING: java.lang.IllegalArgumentException: Bad sample time: 1313012383773. Last update time was 1313012383773, at least one second step is required at org.rrd4j.core.RrdDb.store(Unknown Source) at org.rrd4j.core.Sample.update(Unknown Source) at
Re: [Neo4j] Database error
Did your robot use the REST batch API or the normal REST API? Jim ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Enhanced API wiki page
Hi Peter, I have given your criticism that the API is too heavy to grasp some more thought. I do agree with your assessment that it is heavy to grasp, but don't really know how to make it simpler. N-ary edges (Hyperrelationships) are complex beasts compared to Relationships as defined in the standard Neo4j API. In another post I already showed how BinaryEdge, as a one-on-one mapping of Relationship in standard Neo4j API, is only one of 16 possible two-sided Edges. This added complexity automatically translates into having to deal with more classes. Instead of just Nodes, Relationships and RelationshipTypes, we now have to deal with: Vertices, Edges, EdgeTypes, Connectors and ConnectorTypes. For the n-ary case, there is no other way to deal with this. Of course we could give things a different name, as I have done a couple of times now, but no matter how you slice it, when you want to create an n-ary edge, you will have to provide the vertices to connect. Not only do you have to provide these vertices, it is also imperative you tell where on the edge to place those vertices. This is relatively simple in the case of a BinaryEdge, where we use the method Vertex#createEdgeTo(Vertex, RelationshipType). We only have two Vertices we want to add to the Edge, one of them connecting to the StartConnector, the other connecting to the EndConnector. So in this particular case the choice of Connector can be made implicitly. With arities 2 no such implicit choice of Connector can be made, and with that the entire machinery comes into play. We will need something akin to EdgeType, because that determines the type of Connectors available to an Edge. We need something akin to a Connector, otherwise we don't know were on the Edge to create a connection. We also need something akin to an EdgeElement, otherwise we can't create an Edge in a legal state. I don't think it's smart to allow the user to create a ternary edge, where only one or two sides are connected, just like it's not allowed to create a Relationship in the standard API with one dangling side. I am totally open to renaming things, but I don't think it is possible to really reduce the number of entities involved. As to the names chosen: Connection, Connector, ConnectorType and ConnectionMode follows a neat pattern. There is a Connection, something between a Vertex and an Edge, which is made to a Connector on that Edge. That connector has a type, which defines the Mode of that connector/connection. Initially Connector was named EdgeRole, but that didn't allow the same naming pattern. It's possible to have EdgeRole, EdgeRoleType and EdgeRoleMode, but there is no proper variation on the word EdgeRole that can be used for the denotation of the connection between a Vertex and an Edge. Instead of Connection, Connector, ConnectorType, ConnectorMode, we could use Association, Associator, AssociatorType, AssociatorMode, but I don't know if that makes things simpler. The term EdgeElement is not all the descriptive and I am very much open to suggestions for a better name. It's a class we need when creating n-ary edges. There needs to be some method that creates an Edge, which should have a signature: createEdge(EdgeType, SomethingThatAssociatesVerticesWithAConnectorType...); I have chosen the name EdgeElement instead of SomethingThatAssociatesVerticesWithAConnectorType, but I am not all that happy with that name either. Altogether, n-ary edges are more general than Relationships and with that users of the API need to get acquainted with a couple of more concepts that are left implicit with standard Relationships. It's simply impossible to generalize Relationships to n-ary edges without revealing the underlying complexity. The Wiki page as I have set up now, may need to do more explaining of concepts. It may be that I moved too quickly, that's the down-side of a one-man-project. Things that have become self-evident to me over time may be difficult to grasp for someone new to this model. So, if there are people that see value in having support for n-ary edges in an API on top of Neo4j, please help me out with some of the documentation. A fresh look on things may be helpful to explain things better. Niels From: peter.neuba...@neotechnology.com Date: Thu, 11 Aug 2011 20:46:59 +0200 To: user@lists.neo4j.org Subject: Re: [Neo4j] Enhanced API wiki page Nils, interesting approaches! However, IMHO the API is still too heavy to grasp with ConnectorType, EdgeElement, EdgeType and Edge being involved in creating connections between facts. Is anyone seeing a more fluent/concise approach to this? Also, did you have some ideas about how to traverse or query these hyperedges? Cheers, /peter neubauer GTalk: neubauer.peter Skype peter.neubauer Phone +46 704 106975 LinkedIn http://www.linkedin.com/in/neubauer Twitter http://twitter.com/peterneubauer
[Neo4j] LMAX Disruptor Concurrency Model
I wanted to bring this article the attention of Neo4j engineers. I'm sure many of you have already seen it. The LMAX concurrency system seems to have a few peculiar limitations, but also very specific attention to real hardware limitations. Perhaps their approach to concurrency might have some benefit for Neo4j. http://martinfowler.com/articles/lmax.html http://code.google.com/p/disruptor/ Thanks, McKinley ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Heroku Beta: Neo4j - A Rails Example?
The point is: You don't want to run your webapp in your database. A customer facing rails3 app is an webapp with lots of javascript, UI, images, views etc which also has to be scaled to many instances. On the other hand it needs data to work with. The source of the data is a database in this cause a graph database. But it is much better to talk to your database in terms of your domain (e.g. users, blog posts comments) instead of nodes and relationships. So you basically cut of that lower layer that talks directly to the graph database (and which is very performance sensitive) and move it over to the db. Then you can define the typical use-cases you need for your webapp to render a page and have the domain level endpoints in your database server that provide the _domain level_ data for this rendering process in this granularity and size. HTH Michael P.S: And without a frontend (just having the user management system-domain model running on the graph) (in the neo4j-server in our case) doesn't help you because you don't have to show anything to anyone (no UI). Am 12.08.2011 um 22:02 schrieb Sasha Agafonoff: PPS: I move this discussion to the users list as others probably want to chime in. Hi Michael, Thanks for your email! I am keen to use neo4j.rb rather than neography. The process set out in your example for setting up a back-end neo4j server on Heroku seems pretty straightforward, and I think I understand how I can define domain models and deploy them that way. I think with a bit of effort I could work out how to build something as a Rails front end to work with this, but with my limitations as a coder I don't think I'll do a fantastic job of it. Where I'm struggling is in understanding why I'd need to write two separate apps (backend-frontend) and not be able to write a single app built in the same way as the Rails Project Template (http://neo4j.rubyforge.org/guides/rails3.html) that Andreas has made available on GitHub. Using that template, I could get rolling with a user management system and domain model very quickly. Andreas: not sure if you have any suggestions about bridging this gap? Maybe I'm missing something simple...? Cheers, Sasha On 11 August 2011 18:27, Michael Hunger michael.hun...@neotechnology.com wrote: Sasha, our rails(3) experience is rather limited. We can ask Andreas if he can come up with something, but I can't make any promises. On the frontend web-app side you're free to do whatever rails stuff you want anyway. On the server side we'd like to encourage really tight, persistence centric REST-applicaitions that talk on a domain level to the frontend-webapp that runs on Heroku. So for a backend rails-REST-app it would perhaps best to look for a good rails3-REST-App example and create something similar, just that it uses neo4j.rb instead of the built-in ActiveRecord for persistence. Expose useful domain level endpoints to the frontend webapp and use that one to drive the persistence layer running in the Neo4j Server. If you don't want to use server-side JRuby code, you're limited to a wrapper like neography for the interaction with the graph database. If you'd like to invest time and effort we would be more than happy to integrate it (with attribution) into the documentation. Thanks for your suggestions. Michael P.S. have you seen the general rails3 docs for heroku, I haven't looked into them that much, so I don't know how much one could borrow from there. Am 12.08.2011 um 00:18 schrieb Sasha Agafonoff: Hiya, I'm really pleased to see support kicking off for neo4j on heroku - it's got me interested in picking up my old peoplemap project and doing a full Rails 3-based reboot with the latest version of Andreas' neo4j.rb library. I've joined the beta program, but I'm finding the learning curve pretty challenging... The documentation at http://devcenter.heroku.com/articles/neo4j is really awesome, but it's all centered around two Sinatra-based approaches to accessing the heroku-hosted neo4j instances. The big challenge for me is in working out how to take this (very fine) material and translate it into a Rails 3 context. I will be the first to admit to many limitations as a coder (possibly due to too many years wasted in sales) but I suspect that there will/may be others... :-) Any chance of getting even a very simple Rails 3 example up on this page as well? I think that with just a little more guidance in how to get something configured and running, I could probably go and build something a bit more developed that could contribute to the beta program and advancing neo4j more generally! Cheers, Sasha ___ Neo4j mailing list User@lists.neo4j.org https://lists.neo4j.org/mailman/listinfo/user
Re: [Neo4j] Heroku Beta: Neo4j - A Rails Example?
Sasha you can clone the example github repo (that's also mentioned in the docs): https://github.com/tbaum/script-extension-example Remove the .git directory and add it as a new repo to your github account. Feel free to change whatever you'd like (Gemfile, code, whatever). Michael Am 12.08.2011 um 23:00 schrieb Sasha Agafonoff: Hi Michael, That's all very helpful and makes a huge amount of sense. Thanks very much for committing your time to replying - I appreciate you making the effort! I'd be really grateful for any suggestions from the group/list as to getting started on writing a Rails 3 front end to leverage the backend database. Perhaps if anyone else has started using the Heroku Add-on and they are able to do so, they could share a basic template (perhaps on GitHub) so I could get a better sense of how to get the plumbing working... :-) Cheers, Sasha On 12 August 2011 16:31, Michael Hunger michael.hun...@neotechnology.com wrote: The point is: You don't want to run your webapp in your database. A customer facing rails3 app is an webapp with lots of javascript, UI, images, views etc which also has to be scaled to many instances. On the other hand it needs data to work with. The source of the data is a database in this cause a graph database. But it is much better to talk to your database in terms of your domain (e.g. users, blog posts comments) instead of nodes and relationships. So you basically cut of that lower layer that talks directly to the graph database (and which is very performance sensitive) and move it over to the db. Then you can define the typical use-cases you need for your webapp to render a page and have the domain level endpoints in your database server that provide the _domain level_ data for this rendering process in this granularity and size. HTH Michael P.S: And without a frontend (just having the user management system-domain model running on the graph) (in the neo4j-server in our case) doesn't help you because you don't have to show anything to anyone (no UI). Am 12.08.2011 um 22:02 schrieb Sasha Agafonoff: PPS: I move this discussion to the users list as others probably want to chime in. Hi Michael, Thanks for your email! I am keen to use neo4j.rb rather than neography. The process set out in your example for setting up a back-end neo4j server on Heroku seems pretty straightforward, and I think I understand how I can define domain models and deploy them that way. I think with a bit of effort I could work out how to build something as a Rails front end to work with this, but with my limitations as a coder I don't think I'll do a fantastic job of it. Where I'm struggling is in understanding why I'd need to write two separate apps (backend-frontend) and not be able to write a single app built in the same way as the Rails Project Template (http://neo4j.rubyforge.org/guides/rails3.html) that Andreas has made available on GitHub. Using that template, I could get rolling with a user management system and domain model very quickly. Andreas: not sure if you have any suggestions about bridging this gap? Maybe I'm missing something simple...? Cheers, Sasha On 11 August 2011 18:27, Michael Hunger michael.hun...@neotechnology.com wrote: Sasha, our rails(3) experience is rather limited. We can ask Andreas if he can come up with something, but I can't make any promises. On the frontend web-app side you're free to do whatever rails stuff you want anyway. On the server side we'd like to encourage really tight, persistence centric REST-applicaitions that talk on a domain level to the frontend-webapp that runs on Heroku. So for a backend rails-REST-app it would perhaps best to look for a good rails3-REST-App example and create something similar, just that it uses neo4j.rb instead of the built-in ActiveRecord for persistence. Expose useful domain level endpoints to the frontend webapp and use that one to drive the persistence layer running in the Neo4j Server. If you don't want to use server-side JRuby code, you're limited to a wrapper like neography for the interaction with the graph database. If you'd like to invest time and effort we would be more than happy to integrate it (with attribution) into the documentation. Thanks for your suggestions. Michael P.S. have you seen the general rails3 docs for heroku, I haven't looked into them that much, so I don't know how much one could borrow from there. Am 12.08.2011 um 00:18 schrieb Sasha Agafonoff: Hiya, I'm really pleased to see support kicking off for neo4j on heroku - it's got me interested in picking up my old peoplemap project and doing a full Rails 3-based reboot with the latest version of Andreas' neo4j.rb library. I've joined the beta program, but I'm finding the learning curve pretty challenging... The documentation at
