4store

4store is an efficient, scalable and stable RDF database.

4store was designed by Steve Harris and developed at Garlik to underpin their Semantic Web applications. It has been providing the base platform for around 3 years. At times holding and running queries over databases of 15GT, supporting a Web application used by thousands of people.

Getting started

In this section:

1. Installing prerequisites.
2. Installing 4store.
3. Running 4store.
4. Installing frontend tools only.
5. Other installation hints.

Installing prerequisites

To install Raptor (RDF parser) and Rasqal (SPARQL parser):

# install a 64-bit raptor from freshly extracted source
./configure --libdir=/usr/local/lib64 && make
sudo make install

# similarly for 64-bit rasqal
./configure "--enable-query-languages=laqrs sparql rdql" \
 --libdir=/usr/local/lib64 && make
sudo make install

# ensure PKG_CONFIG_PATH is set correctly
# ensure /etc/ld.so.conf.d/ includes /usr/local/lib64
sudo ldconfig

Installing 4store

./autogen.sh
./configure
make
make install

Running 4store

/usr/local/bin/4s-boss -D

Installing frontend tools only

To install just the frontend tools on non-cluster frontends:

# pre-requisites for installing the frontend tools
yum install pcre-devel avahi avahi-tools avahi-devel

# src/common
(cd src/common && make)

# src/frontend
(cd src/frontend && make && make install)

Other installation hints

Make sure /var/lib/4store/ exists (in a cluster, it only needs to exist on backend nodes) and that the user or users who will create new KBs have permission to write to this directory.

For clusters (or to test cluster tools on a single machine) the frontend must have a file /etc/4s-cluster, which lists all machines in the cluster.

To avoid problems running out of Avahi DBUS connections, modify /etc/dbus-1/system.d/avahi-dbus.conf to:

• Increase max_connections_per_user to 200 or so
• Increase max_match_rules_per_connection to 512 or so (optional)