Can splunk ingestion pipeline drop or route older events?

[hrawat_splunk]

Is there an option to drop older events from the pipeline? Older events can cause frequent bucket rolling and most likely not useful.

[hrawat_splunk · Accepted solution]

Latest splunk release has new added capability that allows older events to be routed or dropped without configuring any regex expression(e.g. INGEST_EVAL).

With this new capability, filtering happens during date time extraction, very early stage in the pipeline by AggregatorProcessor, it's least expensive way to dop/route older events.

New config ROUTE_EVENTS_OLDER_THAN in props.conf can be added to any stanza along with Timestamp extraction configurations. Right after date/time extraction, by default events can be routed to nulllQueue by setting ROUTE_EVENTS_OLDER_THAN.

ROUTE_EVENTS_OLDER_THAN = <non-negative integer>[s|m|h|d]
* If set, AggregatorProcessor routes events older than 'ROUTE_EVENTS_OLDER_THAN'
  to nullQueue after timestamp extraction.
* Default: no default

Example to drop (route to nullQueue) data that is older than 30 days, set ROUTE_EVENTS_OLDER_THAN=30d

[source::/Applications/splunk/var/spool/splunk]
TIME_PREFIX = \d{4}\/\d{2}\/\d{2} \d{2}:\d{2}:\d{2} \w+\s 
MAX_TIMESTAMP_LOOKAHEAD = 21
ROUTE_EVENTS_OLDER_THAN = 30d

[host::foo]
TIME_PREFIX = \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} \w+\s
TIME_FORMAT = %b %d %H:%M:%S %Y
ROUTE_EVENTS_OLDER_THAN = 30d

Routing data based on dest routing key. ( index/queue/_TCP_ROUTING /_SYSLOG_ROUTING)
Route data 30 days and older straight to index queue and avoid regex extraction.

[host::foo]
TIME_PREFIX = \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} \w+\s
TIME_FORMAT = %b %d %H:%M:%S %Y
ROUTE_EVENTS_OLDER_THAN = 30d
queue = indexqueue

Route data 30 days and older to another index

[host::foo]
TIME_PREFIX = \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} \w+\s
TIME_FORMAT = %b %d %H:%M:%S %Y
ROUTE_EVENTS_OLDER_THAN = 30d
index = <30-days-and-older-index>

Index and forward OR HWF specific settings
Route data 30 days and older to another tcpout group

[host::foo]
TIME_PREFIX = \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} \w+\s
TIME_FORMAT = %b %d %H:%M:%S %Y
ROUTE_EVENTS_OLDER_THAN = 30d
_TCP_ROUTING = <send to another cluster - OR - another tcpoutgroup>

Route data 30 days and older to another syslog output group

[host::foo]
TIME_PREFIX = \d{4}/\d{2}/\d{2} \d{2}:\d{2}:\d{2} \w+\s
TIME_FORMAT = %b %d %H:%M:%S %Y
ROUTE_EVENTS_OLDER_THAN = 30d
_SYSLOG_ROUTING = <send to another cluster - OR - another tcpoutgroup>