Use same URL for both query and update - sparql

Question

I know that by default fuseki provides different urls for both query and update, allowing some elegant management.
Now, i want to get a single URL for both update and query. The rationale behind this need is to avoid the propagation of two urls in the codebase.
I know that update and query codes should be separated, but my requests are not mixed. It's just to avoid the propagation of two objects instead of one.
My current config looks like:
<#service1> rdf:type fuseki:Service ;
fuseki:name "dataset" ; # http://host:port/dataset
fuseki:serviceQuery "endpoint" ; # SPARQL query service
fuseki:serviceUpdate "endpoint" ; # SPARQL update service
fuseki:dataset <#dataset> ;
.
In theory, an interface exists at /endpoint, but only accept update. When query with:
prefix sfm: <sfm/>
SELECT DISTINCT ?value
WHERE {
sfm:config sfm:component ?value.
}
the server reports many lines like the following:
INFO [4] POST http://localhost:9876/sfm/endpoint
INFO [4] POST /sfm :: 'endpoint' :: [application/x-www-form-urlencoded] ?
INFO [4] 400 SPARQL Update: No 'update=' parameter (0 ms)
I can't find anything in the doc that specify that query and update service can't be at same place, so i'm assume it's possible and i've just missed something.
However the last line of log is explicit: fuseki waits for an update.
One other solution could be to define the url as localhost/dataset/, and depending if i query or update, add the relevant part at the end, giving respectively localhost/dataset/query and localhost/dataset/update.
But (1) this lead the database to need to have a particular url naming, and (2) it looks like a strong requirement about the triplestore: when i will use another one, it will have to provide the same interface, which could be not possible. (don't know if this feature is implemented in other triplestores)
EDIT: fix the POST/GET error

Answer 1

405 HTTP method not allowed: SPARQL Update : use POST
It looks like you are using GET for an SPARQL Update.
It has correctly routed the operation to the update processor (you can use the same endpoint - including dropping the service part and just using the dataset URL).
However, in HTTP, GET are cacheable operations and should not be used when they can cause changes. a GET may not actually reach the end server but some intermediate respond to it from a web cache.
Use POST.
The same is true if you separate services for query and update.
Original Context
The original question has been edited. The original report was asking about this:
INFO [1] 405 HTTP method not allowed: SPARQL Update : use POST (2 ms)

Answer 2

Answer to the revised and different question:
The endpoint for shared services is the dataset URL:
http://localhost:9876/sfm
Whether update, query or services are available is controlled by the configuration file.
Setting fuseki:serviceQuery and fuseki:serviceUpdate the same is not necessary and is discouraged.