FortiSIEM Rules

FortiSIEM ClickHouse Storage Space Low

Rule ID

PH_Rule_Avail_PH_58

Default Status

Enabled

Description

Detects that ClickHouse disk space usage has reached a low level. Free space percentage on the lowest tier is less than clickhouseSpaceToFreeFactor. System error generated.

Severity

6

Category

Availability

MITRE ATT&CK® Tactics

FortiSIEM

MITRE ATT&CK® Techniques

No Technique Specified

Impacts

Internal

Data Source

FortiSIEM Self Monitoring

Detection

Correlation

Remediation Guidance

Release space on the disk or enlarge the disk or decrease clickhouseSpaceToFreeFactor.

Time Window

If the following pattern or patterns match an ingested event within the given time window in seconds, trigger an incident.

600 seconds

Trigger Conditions

If the following defined pattern/s occur within a 600 second time window.

CHSpaceLow

SubPattern Definitions

SubPattern Name: CHSpaceLow

This is the named definition of the event query, this is important if multiple subpatterns are defined to distinguish them.

SubPattern Query

This is the query logic that matches incoming events

eventType="PH_CLICKHOUSE_STORAGE_FREE_SPACE_LOW" AND phEventCategory=3

Group by Attributes

This defines how matching events are aggregated, only events with the same matching attribute values are grouped into one unique incident ID

hostIpAddr

Aggregate Constraint

This is most typically a numerical constraint that defines when the rule should trigger an incident

COUNT(*)>0 AND AVG(freeDiskMB)>0

Incident Attribute Mapping

This section defines which fields in matching raw events should be mapped to the incident attributes in the resulting incident.

The available raw event attributes to map are limited to the group by attributes and the aggregate event constraint fields for each subpattern

hostIpAddr=CHSpaceLow.hostIpAddr,
freeDiskMB=CHSpaceLow.AVG(freeDiskMB)