I had tried to ask this question earlier and will try and restate the question. I have a graph of people or nodes representing people and each person has a calendar associated with him/her.
The calendar is represented using a Timeline. I came across this old thread (http://lists.neo4j.org/pipermail/user/2011-April/007966.html), which kind of says that implementing the model of Timeline-per-Node is difficult with LuceneTimeline and the older B-tree implementation was more efficient. Is it still true?
Is there a B-tree implementation available in version 1.8 and higher ?
Has anyone faced a similar problem ?
I am working on building a plugin to expose a REST interface for managing Timelines. The problems I'm facing are:
How to retrieve an existing LuceneTimeline ?
How to associate a Timeline with every Node ?
Are there any examples anywhere ?
Thanks,
https://github.com/neo4j/graph-collections/blob/master/src/test/java/org/neo4j/collections/timeline/TestTimeline.java is probably what you should. This however does not work great over REST as it is using the Java Embedded API. Either send over Groovy code, or do a custom Neo4j Server plugin, see http://docs.neo4j.org/chunked/stable/server-plugins.html .
Also, you can do something like that with Cypher, see http://docs.neo4j.org/chunked/stable/cypher-cookbook-path-tree.html
Related
I want to present release data complexity which is associated with each node like at epic, userstory etc in grafana in form of charts but grafana do not support neo4j database.Is there any way Directly or indirectly to present neo4j database in grafana?
I'm having the same issues and found this question among others. From my research I cannot agree with this answer completely, so I felt I should point some things out, here.
Just to clarify: a graph database may seem structurally different from a relational or time series database, but it is possible to build Cypher queries that basically return graph data as tables with proper columns as it would be with any other supported data source. Therefore this sentence of the above mentioned answer:
So what you want to do is just not possible.
is not absolutely true, I'd say.
The actual problem is, there is no datasource plugin for Neo4j available at the moment. You would need to implement one on your own, which will be a lot of work (as far as I can see), but I suspect it to be possible. For me at least, this will be too much work to do, so I won't use any approach to read data directly from Neo4j into Grafana.
As a (possibly dirty) workaround (in my case), a service will regularly copy relevant portions of the Neo4j graph into a relational database (or a time series database, if the data model is sufficiently simple for that), which Grafana is aware of (see datasource plugins), so I can query it from there. This is basically the replication idea also given in the above mentioned answer. In this case you obviously end up with at least 2 different database systems and an additional service, which is not so insanely great, but at the moment it seems to be the quickest way to resolve the problem with the missing datasource plugin. Maybe this is applicable in your case, too.
Using neo4j's graphite metrics you can actually configure data to be sent to grafana, and from there build whichever dashboards you like.
Up until recently, graphite/grafana wasn't supported, but it is now (in the recent 3.4 series releases), along with prometheus and other options.
Update July 2021
There is a new plugin called Node Graph Panel (currently in beta) that can visualise graph structures in Grafana. A prerequisite for displaying your graph is to make sure that you have an API that exposes two data frames, one for nodes and one for edges, and that you set frame.meta.preferredVisualisationType = 'nodeGraph' on both data frames. See the Data API specification for more information.
So, one option would be to setup an API around your Neo4j instance that returns the nodes and edges according to the specifications above. Note that I haven't tried it myself (yet), but it seems like a viable solution to get Neo4j data into Grafana.
Grafana support those databases, but not Neo4j : Graphite, InfluxDB, OpenTSDB, Prometheus, Elasticsearch, CloudWatch
So what you want to do is just not possible.
You can replicate your Neo4j data inside of those database, but the datamodel is really different ... (timeseries vs graph).
If you just want to have some charts, you can use Apache Zeppeline for that.
I need to share a Neo4J graph visualization with end users. They should be able to interact with the graph, and perform some very basic querying. For example:
- show me the relationships up to 3 hops away from node named 'Joe'
A first option would be to just give them the standard user interface (usually exposed at port 7474); however this is too powerful as they could perform anything in Cypher.
Is there any way of restricting this interface (so that they cannot trigger expensive queries or even graph updates)? Or maybe other open source / community alternatives?
Thanks
If you are using the Enterprise Edition of neo4j, you will have access to extensive authentication and authorization capabilities, including the ability to assign a reader role to specific user names.
If you do want to use the standard browser interface, you can apply some settings on the neo4j.conf file that may help you out:
dbms.transaction.timeout=10s
dbms.read_only=true
dbms.transaction.timeout will terminate queries exceeding the timeout, so that can prevent expensive queries.
dbms.read_only makes the entire db instance read-only.
You may also build a custom web UI that calls the REST endpoint (need to auth in headers)
or
create an unmanaged extension
https://neo4j.com/docs/java-reference/3.1/#server-unmanaged-extensions
I suggest you the chapter 8 of the excellent book Learning Neo4j, by Rik Van Bruggen. This book is available for download at Neo4j web site.
One of the sections of this chapter shows some open source visualization libraries and visualization solutions.
EDIT 1:
Analyzing a bit more the chapter 8 of the Learning Neo4j book I believe that a promising tool for your use case is the paid solution Linkurio.us (you can run a demo in the site). This solution has a native integration with Neo4j and others graph databases.
EDIT 2:
Alternatively you can build your own visualization solution with a graph visualization library in JavaScript, for example. Here a very useful answer from another StackOverflow question that lists more some libraries that can help you.
GitHub for Neo4J?
I'm evaluating graph databases as a possible solution for modeling a complex computer network. It occurs to me something like a revision control system would be useful for planning and testing updates to the database. I had been assuming that either we would instantiate a test network graph for such planning and then write a routing to sync the changes.
I see that this question has been asked and answered for relational databases (How do you maintain revision control of your database structure?). But I'm asking for graph databases, probably Neo4J.
In that relational thread someone pitches the Rails approach of making rollback a required element of database development. I like this idea too; I'm not sure how easy it is in graph databases.
How is this handled in the real world?
I found your question while also searching for an answer, so I don't have tested solutions to offer. But I can share that there's some discussion of this at How do I implement revisions with neo4j?, including a specific case at Neo4j / Strategy to keep history of node changes.
There's also a more detailed blog post at http://iansrobinson.com/2014/05/13/time-based-versioned-graphs/, which weighs the read-time / write-time / storage requirements of several alternatives. It also includes a number of diagrams and example queries that helped me wrap my head around what all this would look like.
Hope that's still useful, lo these months later, and sorry I can't be of more help! If you've found something that works in the meantime, can you let us know?
I am planning to write a Node.js-powered RESTful web service that I will use for a mobile application which provides some sort of location based features. The most basic use case is going to look something like this:
the user can create a resource by sending a request to the web service containing the resource's name and the user's current location (latitude and longitude)
the web service will store the metadata about this resource internally in some sort of collection
the user can query the web service for a list of resources within 5km of his current location
One of the first problems that came up in my mind was scalability. Let's suppose that at some point in the future the server will hold metadata for 1 million resources. When a user will query for nearby results, looping through 1 million entries to compute the distance will take forever.
There are many services out there that have the same flow, so I thought implementing something like this is not going to take me a lot of time. I might have been wrong.
I am now two days into researching proven methods and algorithms. By now I have read everything I could put my hands on about QuadTrees, Geohases, databases with spatial indexing support, formulas and so on. However, I still can't get the whole picture of how everything is going to work.
I was hoping that maybe someone who has worked on something similar could share his insight on what approach might be the most suitable considering this use case and the technologies that I am planning to use. Also, a short description of how it can be implemented would help me a lot!
For those who are also looking for more information on this topic out of curiosity, my answer might not provide much clearance. However, some answers in here might help you understand how you could achieve proximity searches using Geohashes.
My approach, after doing a little research on Redis, will be not to overcomplicate things and just use the tools that are already out there. It has out of the box support for spatial indexing and will most probably meet all my persistance requirements for this project.
Apparently MongoDB also comes with built-in support for geodata. In fact, even RDBMS like MySQL or SQLite do come with such capabilities.
I have a Neo4j application that uses the legacy Lucene indexes on certain relationship properties. Whenever I query these I am looking for exact matches, and all of them. While doing some profiling I discovered that the application is spending a highly disproportionate amount of time retrieving these results as it is pulling them in chunks from a prioritized queue. Given that I do not care about the ordering and want all of the results, what can I do to change the underlying behavior?
From my own searching, I came across Lucene's Collector implementations and it seems like a custom one that collects everything and never bothers scoring could be the answer, but I do not know how I can inject one into Neo4j. I am not opposed to using reflection or other means if it is not actually supported by Neo4j.
The application accesses Neo4j via the embedded Java methods.
We're working on some of that as part of our upgrade to Lucene5, there custom collectors for some of these use-case will be implemented. Hopefully we can make something available in the next weeks.