This article describes the information why flowd is crashing and generating core dumps after enabling jflow v9 on SRX.

When Jflow v9 configuration is changed with inactive-timeout less then "previous flow-inactive-timeout + 180" seconds then it may cause flowd process to crash and result in traffic outage. If a flow-inactive-timeout value is not configured, it will take the default value of 60 seconds.

> Jflow config which triggers this issue

set services flow-monitoring version9 template template-name flow-inactive-timeout seconds (any value less then "previous flow-inactive-timeout + 180" seconds) 

> Flowd will generate core dumps like this
User@DEVICE> show system core-dumps no-forwarding

/var/crash/*core*: No such file or directory
-rw-rw----  1 root  wheel  166756476 Dec 13 11:13 /var/tmp/flowd_octeon_hm.core-tarball.0.tgz

This issue is being tracked in PR 1688627.

Workaround:

Please configure flow-inactive-timeout to be greater than the previous "flow-inactive-timeout + 180" seconds. If the "flow-inactive-timeout" if not configured, is default is 60 seconds
set services flow-monitoring version9 template template-name flow-inactive-timeout 220

Resolved in: 

junos:20.2R3-S6

junos:20.3R3-S6

junos:20.4R3-S5

junos:21.1R3-S4 

junos:21.2R3-S4

junos:21.3R3-S3

junos:21.4R3-S2

junos:22.1R3

junos:22.2R2

junos:22.2R3

junos:22.3R2

junos:22.4R1

junos:23.1R1