coutinhodesousa/tentris

Tentris: A Tensor-based Triple Store

Tentris is a triple store to query RDF data using SPARQL. It is based on tensors and tensor algebra. Currently, it supports SELECT queries with or without DISTINCT and a WHERE-block with triple patterns.

Further SPARQL features will follow.

download

Precompiled linux binaries are provided under Release. Newer release binaries are fully statically linked and have no dependencies.

Docker images of the HTTP endpoint are provided at Docker Hub.

running tentris

Tentris provides two ways of running it. Either as a HTTP endpoint or as a interactive commandline tool. Make sure you build Tentris successfully, before proceeding below.

HTTP endpoint

start

To start Tentris as a HTTP endpoint run

tentris_server -p 8090 -f my_nt_file.nt

to load the data from the provided .nt file and serve SPARQL endpoint at port 8090. For more options commandline options see tentris_server --help.

query

The endpoint may now be queried locally at: 127.0.0.1:8090/sparql?query=*your query*.

Notice: the query string *your query* must be URL encoded. You can use any online URL encoder like https://meyerweb.com/eric/tools/dencoder.

currently deactivated: An additional endpoint is provided at 127.0.0.1:8090/stream using chunk encoded HTTP response. This endpoint should be used for very large responses (>1mio results).

usage example

Consider the query below against a SP²Bench data set:

PREFIX rdf:   <http://www.w3.org/1999/02/22-rdf-syntax-ns#>
PREFIX bench: <http://localhost/vocabulary/bench/>

SELECT DISTINCT ?article
WHERE {
  ?article rdf:type bench:Article .
  ?article ?property ?value 
}

To run the query start Tentris with:

tentris_server -p 3030 -f sp2b.nt 

You can find a populated sp2b.nt file in tests/dataset/sp2b.nt.

now, visit the follwing IRI in a browser to send the query to your Tentris endpoint:

http://127.0.0.1:3030/sparql?query=PREFIX%20rdf%3A%20%20%20%3Chttp%3A%2F%2Fwww.w3.org%2F1999%2F02%2F22-rdf-syntax-ns%23%3E%0APREFIX%20bench%3A%20%3Chttp%3A%2F%2Flocalhost%2Fvocabulary%2Fbench%2F%3E%0A%0ASELECT%20DISTINCT%20%3Farticle%0AWHERE%20%7B%0A%20%20%3Farticle%20rdf%3Atype%20bench%3AArticle%20.%0A%20%20%3Farticle%20%3Fproperty%20%3Fvalue%20%0A%7D

commandline tool

For small experiments it is sometimes more convenient to use a commandline tool for querying an RDF graph. Therefore, Tentris provides a commandline interface.

To start Tentris as a interactive commandline tool, run:

tentris_terminal -f my_nt_file.nt

After the RDF data from my_nt_file.nt is loaded, you type your query and hit ENTER. After the result was printed, you can enter your next query.

For more commandline options see tentris_terminal --help.

prerequisites for compiling

build tools

Tentris is known to build successfully on Ubuntu 18.10 and newer. Building was tested with GCC 9 and clang 9.

The following packages are required to build Tentris:

sudo apt install build-essential uuid-dev g++ git openjdk-8-jdk python3-pip python3-setuptools python3-wheel

Additionally, a recent version of conan is required:

pip3 install --user conan

dependencies

Most required dependencies are installed via conan. Therefore, Add the respective remotes:

conan remote add bincrafters https://api.bintray.com/conan/bincrafters/public-conan
conan remote add tsl https://api.bintray.com/conan/tessil/tsl
conan remote add stiffstream https://api.bintray.com/conan/stiffstream/public 
conan remote add dice-group https://api.bintray.com/conan/dice-group/tentris

Additionally, a statically linked version of the Serd library is required. As the packages in the deb/rpm repositories include only a dynamic library, we need to compile it manually:

clone --branch v0.30.2 https://gitlab.com/drobilla/serd.git
cd serd
git submodule update --init --recursive
./waf configure --static
sudo ./waf install
cd -

build

After you installed all dependencies, you are ready to build Tentris. Make sure you are connected to the internet as Tentris downloads things at several points throughout the build processes.

If you did not so far, clone Tentris:

git clone https://github.com/dice-group/tentris.git

Make sure you are in the cloned folder:

cd tentris

Now, make a build directory and enter it.

mkdir build 
cd build

Get and build the dependencies with conan:

conan install .. --build=missing --settings compiler.libcxx="libstdc++11"

Generate the build skripts with CMAKE and run the build:

cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release .. 
make -j tentris_server tentris_terminal

Now is the time to get yourself a coffee. In about When you build Tentris for the first time, it will take some time.

The binaries will be located at tentris/build/bin.

debug and tests

To compile Tentris with debugging symbols, proceed as above but change the cmake command to cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug .. .

To compile the tests, run cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Debug -DTENTRIS_BUILD_TESTS=True .. for debugging or cmake -G "Unix Makefiles" -DCMAKE_BUILD_TYPE=Release -DTENTRIS_BUILD_TESTS=True .. for release.

docker

• A docker image is available on docker hub. Get it with

  docker pull dicegroup/tentris_server

• To show the available commandline options, run

  docker run --rm dicegroup/tentris_server --help

• Tentris uses by default the port 8090, so make sure you forward it, e.g.

  docker run --publish=9080:9080 dicegroup/tentris_server

• To load data, mount its enclosing directory to the container and tell Tentris, to load it:

  docker run -v /localfolder:/datasets --publish=9080:9080 dicegroup/tentris_server -f /datasets/yourRDFfile.nt

• By default, Tentris writes logs to the /tentris in the container. To make logs available outside the container, you can mount them as well:

  docker run -v /local-log-dir:/tentris --publish=9080:9080 dicegroup/tentris_server

• The other command-line tools tentris_terminal, ids2hypertrie and ids2hypertrie are also available in the container. Run them like:

  docker run -it  dicegroup/tentris_server tentris_terminal