AllegroGraph always provides an unstructured log of system activity. This is mainly for debugging and to aid in technical support. AllegroGraph also provides a structured system audit log which tracks important changes to the server and its triple-stores. This log is useful for system and database administrators conscious of security and performance. Note that structured logging is not enabled by default but can be turned on by editing the AllegroGraph configuration file (the details are in the server configuration document).
Regardless of the security settings, only superuser has access to the system catalog.
AllegroGraph's AGWebView tool provides an interface to query the audit log; see the AGWebView documentation for more details.
The web interface (again, AGWebView documentation) provides access (for superusers) to audit information and you should look at the examples there to see what is available and what to expect. However, here are details about what is stored.
The log consists of information about a series of events. Each event has a type, a number of parameters specific to the event type, and some contexts that identify the source of the event and the components of the system it passed through. For example, the following event (presented in Turtle describes the creation of a free text index called "foo" at 2013-02-26 10:21:29 UTC. The database for which the index was created goes by the name "test db" and is in catalog "test catalog".
@prefix : <http://franz.com/allegrograph/4.11/audit-log#> . @prefix xsd: <http://www.w3.org/2001/XMLSchema#> . @prefix rdfs: <http://www.w3.org/2000/01/rdf-schema#> . @prefix temp: <http://franz.com/ns/allegrograph/3.0/temporal/> .  a :createFreeTextIndex ; :version "http://www.franz.com/agraph/support/documentation/4.11/" ; temp:time "2013-02-26T10:21:29Z"^^xsd:dateTime ; :db [ a :db ; :name "test db" ; :catalog "test catalog" ] ; :index "foo" ; :backend [ temp:time "2013-02-26T10:21:29Z"^^xsd:dateTime ; a :backend ; :pid 4605 :servicePort 55713 ; :remoteHost "127.0.0.1" ; :remotePort 52307 ; :localHost "127.0.0.1" ; :localPort 44860 ] ; :frontend [ temp:time "2013-02-26T10:21:29Z"^^xsd:dateTime ; a :frontend ; :user "joe" ; :pid 9877 :servicePort 9233 ; :remoteHost "127.0.0.1" ; :remotePort 36927 ; :localHost "127.0.0.1" ; :localPort 42194 ] .
There are three contexts carrying additional information about the event. The request was received at the main port of the front end, from user "joe". It was then forwarded to the backend process with pid 4605. The main port of the backend's http server was 55713.