why no LOGOUT event record on some OSes

[Li Zhijian]

Hi guys

I'm new to audit, then i observed that there is no LOGOUT event record 
in audit.log
on my ubuntu 18.04 and debian 8 OSes, while the centos7.4 and fedora33 
have it.

I google it but get no answer, so am I missing something about the audit 
rules or
special audit configuration ?

Below are part of records of audit in my several OSes.

debian 8
lizhijian at lkp-bingo:~$ sudo aureport -e -i --summary | grep -i USER
[sudo] password for lizhijian:
6  USER_START
6  USER_END
4  USER_ACCT
4  USER_CMD
2  USER_AUTH
2  USER_LOGIN

ubuntu 18.04
lizj at FNSTPC:~$ sudo aureport -e -i --summary | grep USER
43241  USER_END
16946  USER_START
16718  USER_ACCT
658  USER_AUTH
543  USER_CMD
255  USER_LOGIN
9  USER_ROLE_CHANGE
5  USER_ERR
2  USER_CHAUTHTOK
1  ADD_USER

fedora 33
[root at iaas-rpma linux]# aureport -e -i --summary | grep USER
7356  CRYPTO_KEY_USER
2103  USER_START
1649  USER_END
1268  USER_ACCT
1108  USER_ROLE_CHANGE
1029  USER_AUTH
895  USER_LOGIN
789  USER_LOGOUT
60  USER_CMD
14  USER_ERR
3  USER_MGMT
3  USER_CHAUTHTOK
1  ADD_USER

Thanks