This topic does not apply to MemSQL Helios.
As of the time of this publication, audit logging features are made available and licensed only as part of the MemSQL Advanced Security Option. Before using or implementing this functionality, please consult with your enterprise’s licensing administrator to confirm that your enterprise has purchased the necessary Advanced Security Option license from MemSQL.
Before you can enable audit logging, you must configure each MemSQL node’s memsql.cnf file. There are five configuration variables associated with audit logging:
auditlog_level(Required)auditlog_rotation_size(Required if logging is enabled)auditlog_rotation_time(Required if logging is enabled)auditlogsdir(Required if logging is enabled)auditlog_disk_sync
Each of these variables have a default setting when MemSQL is first installed. You can show the default settings by executing the following statement:
SHOW GLOBAL VARIABLES LIKE 'audit%';
****
+------------------------+-----------------------------------------+
| Variable_name | Value |
+------------------------+-----------------------------------------+
| auditlog_level | OFF |
| auditlog_disk_sync | OFF |
| auditlog_rotation_size | 134217728 |
| auditlog_rotation_time | 3600 |
| auditlogsdir | /var/lib/memsql/master-3306-1/auditlogs |
+------------------------+-----------------------------------------+
These variables are described in the table below:
| Variable Name | Value |
|---|---|
auditlog_level |
Specifies the audit logging level. By default, this value is set to OFF. Ten other levels are available — see Logging Levels for more information. |
auditlog_disk_sync |
Specifies whether every audit log record is synchronously written and persisted to the disk. By default, this value is set to OFF and audit log disk syncs are delayed. |
auditlog_rotation_size |
Specifies the maximum size per log file in bytes. By default, this value is set to 128MB, or 134217728 bytes. |
auditlog_rotation_time |
Specifies the maximum time duration to write to a single log file in seconds. The log rotation check happens when SingleStore DB writes audit entries to the log. Therefore, in some rare cases (and especially on leaf nodes) where there are not a lot of entries written to the log, it is possible that the log is not rotated for greater periods of time than configured in auditlog_rotation_time. By default, this value is set to 1 hour, or 3600 seconds. |
auditlogsdir |
Specifies the local or network directory to write log files. By default, this value is set to the auditlogs directory in your node’s MemSQL directory. For example: /var/lib/memsql/<node-type>-<port>/auditlogs |
Before enabling audit logging, ensure that the default configuration settings are acceptable. Namely, validate the settings for the following engine variables:
auditlog_rotation_sizeauditlog_rotation_timeauditlogsdir
These settings should be set to acceptable values before enabling logging. While they can be changed later, these settings are loaded only upon MemSQL startup from each node’s memsql.cnf file. Therefore, whenever a change is made to any audit logging setting (including auditlog_level), each node in your cluster must be restarted to apply the new configuration.
How to Enable and Configure Audit Logging
Audit logging variables are set in the memsql.cnf file in each node’s MemSQL path. By default, this path is /var/lib/memsql/<node-type>-<port>, or /var/lib/memsql/master-3306 for a typical master aggregator node.
Always ensure that each node in your cluster has been stopped before making audit logging configuration changes.
-
Open a new console window with access to the node you want to configure.
-
Stop any MemSQL processes on the node. There are two common ways to stop MemSQL nodes:
- Using the sdb-admin stop-node command
sdb-admin stop-node --all- Using the memsqlctl stop-node command
memsqlctl stop-node --all -
After the node has been stopped, navigate to the memsql.cnf path for the node and open the file with a text editor.
-
Add the four required audit logging variables. For example, consider the following sample configuration:
max-pooled-connections = 100 max-connection-threads = 256 default-partitions-per-leaf = 8 max_subselect_aggregator_rowcount = 0 allow_user_functions auditlog_level = ADMIN-ONLY auditlog_disk_sync = OFF auditlog_rotation_size = 134217728 auditlog_rotation_time = 3600 auditlogsdir = /var/lib/memsql/master-3306-1/auditlogs -
When your configuration is complete, save the memsql.cnf file and exit the text editor.
WarningRepeat the configuration update process for each node in your cluster before continuing.
-
Restart the node in one of two ways:
sdb-admin start-node --all
memsqlctl start-node --all
- Ensure that MemSQL starts successfully. Once started, validate that your settings have been loaded successfully by executing the following command:
SHOW GLOBAL VARIABLES LIKE 'audit%';
****
+------------------------+-----------------------------------------+
| Variable_name | Value |
+------------------------+-----------------------------------------+
| auditlog_level | ADMIN-ONLY |
| auditlog_disk_sync | OFF |
| auditlog_rotation_size | 134217728 |
| auditlog_rotation_time | 3600 |
| auditlogsdir | /var/lib/memsql/master-3306-1/auditlogs |
+------------------------+-----------------------------------------+
Once each node in your cluster has been updated with the new configuration changes, audit logging has been successfully configured and enabled.
