Using halyard with rest api

[ganesh chandra]

Hello All,

I have been using halyard to run rdf4j on aws emr. I have been trying to use the rest api provided by rdf4j to access the server. But I have not been successful. I have been trying to see the repos that I have created on the server. But have been unable to do so.

The command I have been using:

curl -X GET -H  "Content-Type: application/x-www-form-urlencoded" "http://18.111.23.158:8080/rdf4j-workbench/repositories/" .

What i have done:

1. I scp'd the halyard zip package

2. I unziped the folder.

3. I created the repo with 

• create hbase
• clicked enter a lot of times and gave the name and id as 'hal1'
• open hal1
• load data

Then I tried to do the run the above curl command.

Is there something wrong that I am doing?

Thanks,

Ganesh

[Adam Sotona]

Hi Ganesh,

I'm trying to understand what steps you exactly did.

From your description I see you have an EMR cluster and on one node you've probably setup a web server with rdf4j-server and rdf4j-workbench web applications.

However you also mention "create hbase", which is a console command.

Rdf4j as well as Halyard consist of several layers.

Rdf4j rest API is a part of rdf4j-server web application, it is managed through rdf4j-workbench and it must be deployed in an application web server (Tomcat deployment is described in the documentation). 

If you need SPARQL endpoint rest api to access particular dataset, you can rely on particular repository within the rd4j-server (created using rdf4j-workbench). Or alternatively (as a very new and experimental Halyard feature) you can run Halyard Endpoint to query-only one specific dataset through SPARQL query rest api.

If you need just access the data using SPARQL queries and SPARQL updates, you can do it using rdf4j-workbench, or through rest calls to rdf4j-server, or rest calls to Halyard Endpoint (query only), or from rd4j console, or by using Halyard command-line tools.

However rdf4-console does not setup any rest server, it has just embedded Halyard layer and embedded rdf4j framework and direct access to the data in HBase. Also please notice the difference between datasets and repositories paragraph in Halyard documentation. Rdf4j repositories are meta-descriptors individually locally configured in each server or console instance, however datasets are backed by Hbase tables and they exist across the whole cluster globally.

I hope this helped to better understand the architecture.

Thanks,

Adam

-------- Původní zpráva --------

Od: ganesh chandra <ganesh....@gmail.com>

Datum: 26.03.19 6:14 (GMT+01:00)

Komu: Halyard Users <halyar...@googlegroups.com>

Předmět: Using halyard with rest api

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