QDB configuration is optional. The defaults launch a server listening on with no security. This is appropriate for many applications. On startup QDB looks for a qdb.conf or file in /etc and the current directory with settings the latter having priority. Example /etc/

host =
port = 9554
dataDir = data
initialAdminPassword = admin

For an up-to-date listing of configuration properties and default values please look at qdb-default.conf in the source code.

Java Options

The startup scripts define QDB_SERVER_OPTS="-server" and source /etc/default/qdb for overrides. These options are passed to the "java" command that runs QDB. You might want to configure memory usage. Example /etc/default.qdb:

# Start with 16m heap
QDB_SERVER_OPTS="-server -Xmx16m -Xms16m -XX:+UseCompressedOops"


QDB logs messages to the console by default, which the startup scripts redirect to /var/log/qdb/qdb.log (Linux) or to ./qdb.log (Generic). GELF logging to a Graylog2 server is also supported. Sample /etc/

# Port is optional, default is 12201 (Graylog2 default)
graylog2 =
# Default is 0.9.6
graylog2ServerVersion = 0.9.6
# Only INFO, WARN and ERROR messages are sent to Graylog2, DEBUG only to console
logLevel = DEBUG
# Default logLevel is INFO