關於ora-02391問題的總結(r6筆記第40天)
關於ORA問題的分析和解決其實是一個很好的學習思路,抓住一個每一個ORA錯誤,然後進一步分析一些原因,總結,總會有不一樣的收穫,還是那句話,任何問題背後都是有原因的。
今天早上,開發的同事反饋說客戶端中丟擲了ora錯誤。
ORA-02391: exceeded simultaneous SESSIONS_PER_USER limit
希望我們能夠幫忙看看是什麼原因,怎麼修復一下。
這個問題其實還是比較清晰的,就是在我們設定的profile中會定義對應session數限制,比如存在使用者test,sessions_per_user為50,則test使用者最多使用50個session.
預設的profile是DEFAULT ,在建立資料庫之後會做基本的初始化,比如密碼的過期時間等等
SQL> select *from DBA_PROFILES WHERE PROFILE='DEFAULT'
PROFILE RESOURCE_NAME RESOURCE LIMIT
------------------------------ -------------------------------- -------- ----------------------------------------
DEFAULT COMPOSITE_LIMIT KERNEL UNLIMITED
DEFAULT SESSIONS_PER_USER KERNEL UNLIMITED
DEFAULT CPU_PER_SESSION KERNEL UNLIMITED
DEFAULT CPU_PER_CALL KERNEL UNLIMITED
DEFAULT LOGICAL_READS_PER_SESSION KERNEL UNLIMITED
DEFAULT LOGICAL_READS_PER_CALL KERNEL UNLIMITED
DEFAULT IDLE_TIME KERNEL UNLIMITED
DEFAULT CONNECT_TIME KERNEL UNLIMITED
DEFAULT PRIVATE_SGA KERNEL UNLIMITED
DEFAULT FAILED_LOGIN_ATTEMPTS PASSWORD UNLIMITED
DEFAULT PASSWORD_LIFE_TIME PASSWORD UNLIMITED
DEFAULT PASSWORD_REUSE_TIME PASSWORD UNLIMITED
DEFAULT PASSWORD_REUSE_MAX PASSWORD UNLIMITED
DEFAULT PASSWORD_VERIFY_FUNCTION PASSWORD NULL
DEFAULT PASSWORD_LOCK_TIME PASSWORD UNLIMITED
DEFAULT PASSWORD_GRACE_TIME PASSWORD UNLIMITED
sql> select username,profile from dba_users where username=’ USER_TEST’;
USERNAME PROFILE
------------------------------ ------------------------------
USER_TEST APP_TEST
SQL> select * from dba_profiles where profile='APP_TEST';
PROFILE RESOURCE_NAME RESOURCE LIMIT
------------------ -------------------------------- -------- ----------------------------------------
APP_TEST COMPOSITE_LIMIT KERNEL DEFAULT
APP_TEST SESSIONS_PER_USER KERNEL 20
APP_TEST CPU_PER_SESSION KERNEL DEFAULT
APP_TEST CPU_PER_CALL KERNEL DEFAULT
APP_TEST LOGICAL_READS_PER_SESSION KERNEL DEFAULT
APP_TEST LOGICAL_READS_PER_CALL KERNEL DEFAULT
APP_TEST IDLE_TIME KERNEL DEFAULT
APP_TEST CONNECT_TIME KERNEL DEFAULT
APP_TEST PRIVATE_SGA KERNEL DEFAULT
APP_TEST FAILED_LOGIN_ATTEMPTS PASSWORD DEFAULT
APP_TEST PASSWORD_LIFE_TIME PASSWORD DEFAULT
APP_TEST PASSWORD_REUSE_TIME PASSWORD DEFAULT
APP_TEST PASSWORD_REUSE_MAX PASSWORD DEFAULT
APP_TEST PASSWORD_VERIFY_FUNCTION PASSWORD DEFAULT
APP_TEST PASSWORD_LOCK_TIME PASSWORD DEFAULT
APP_TEST PASSWORD_GRACE_TIME PASSWORD DEFAULT
select u.username||' with related profile '||p.profile||' has potential issue on '||p.resource_name ||' current value is '||s.cnt||' of '||p.limit
from dba_profiles p,
(select username,count(*)cnt from v$session where username is not null group by username) s,
dba_users u
where p.RESOURCE_NAME = 'SESSIONS_PER_USER'
and p.profile=u.profile
and s.username=u.username
and p.profile !='DEFAULT'
and s.cnt*100/decode(p.limit,'DEFAULT',999)>=90;
返回結果類似下面的形式。
-------------------------------------------------------------------------------------------------------------
APP_TEST with related profile PF_APP_TEST1 has potential issue on SESSIONS_PER_USER current value is 29 of 31
APP_TEST2 with related profile PF_APP_TEST2 has potential issue on SESSIONS_PER_USER current value is 60 of 6
進一步改進,我們可以加入orabbix中,這樣我們可能比開發還早收到報警郵件,問題處理也更有效