Configuring and using data auditing
Auditing is implemented as a log4j-based integration. DataStax Enterprise places the audit log in the directory indicated by a log4j.property. After the file reaches a threshold, it rolls over, and the file name is changed. The file names include a numerical suffix determined by the maxBackupIndex.
The audit logger logs information on the node set up for logging. For example, node 0 has audit turned on, node 1 does not. Issuing updates and other commands on node 1 does not generally show up on node 0’s audit log. To get the maximum information from data auditing, turn on data auditing on every node. The log4j supports data stored on the file system or in Cassandra.
Auditing is configured through a text file in the file system, so the file is vulnerable to OS-level security breaches. Store the file on an OS-level encrypted file system using Gazzang, for example, to secure it.
Audit logging of queries and prepared statements submitted to the DataStax Java Driver, which uses the CQL binary protocol, is supported.
Configuring data auditing¶
You can configure which categories of audit events should be logged and also whether operations against any specific keyspaces should be omitted from audit logging.
Open the log4j-server.properties file in the following
- Packaged installs:/etc/dse/cassandra
- Tarball installs:/resources/cassandra/conf
To configure data auditing, uncomment these properties, and ensure that the
default properties are set.
To disable data auditing, comment out log4j.logger.DataAudit, log4j.additivity.DataAudit, and log4jappender.A. This removes almost all auditing overhead. The Log4J audit logger logs at INFO level, so the DataAudit logger must be configured at INFO (or lower) level in log4j-server.properties. Setting the logger to a higher level, such as WARN, prevents any log events from being recorded, but it does not completely disable the data auditing. Some overhead occurs beyond that caused by regular processing.
Property Default Description log4j.logger.DataAudit INFO, A Produce INFO-level logs. log4j.additivity.DataAudit false Prevents logging to the root appender. log4j.appender.A org.apache.log4j.RollingFileAppender Prevents logging to the root appender. log4j.appender.A.File /var/log/cassandra/audit.log Sets the file and path of the log file. log4j.appender.A.bufferedIO true True improves performance but will not be real time; set to false for testing.
Set other general options to tune the logging, for example uncomment these
properties and accept the following defaults:
Uncomment and set log4j.appender.A.filter.1.ActiveCategories to ALL or to a
combination of these settings:
Setting Logging ADMIN Logs describe schema versions, cluster name, version, ring, and other admin events ALL Logs everything: DDL, DML, queries, and errors AUTH Logs login events DML Logs insert, update, delete and other DML events DDL Logs object and user create, alter, drop, and other DDL events DCL Logs grant, revoke, create user, drop user, and list users events QUERY Logs all queriesSet the ActiveCategories property to a comma separated list of the categories to include in the audit log output. By default, this list is empty so unless specified, no events are included in the log. Events are generated even if not included in the log, so set this property.
You can disable logging for specific keyspaces. Set this property as follows to
prevent logging to specified keyspaces:
log4j.appender.A.filter.1.ExemptKeyspaces=do_not_log,also_do_not_logTo prevent the audit logger from logging information about itself when using the Cassandra log4j appender, exempt the keyspace from the appender logs.
The audit log section of the log4j-server.properties file should look something like this:
log4j.logger.DataAudit=INFO, A log4j.additivity.DataAudit=false log4j.appender.A=org.apache.log4j.RollingFileAppender log4j.appender.A.File=/var/log/cassandra/audit.log log4j.appender.A.bufferedIO=true log4j.appender.A.maxFileSize=200MB log4j.appender.A.maxBackupIndex=5 log4j.appender.A.layout=org.apache.log4j.PatternLayout log4j.appender.A.layout.ConversionPattern=%m%n log4j.appender.A.filter.1=com.datastax.bdp.cassandra.audit.AuditLogFilter log4j.appender.A.filter.1.ActiveCategories=ALL log4j.appender.A.filter.1.ExemptKeyspaces=do_not_log,also_do_not_log
Restart the node to see changes in the log.