Oracle死锁一例(ORA-00060)，锁表导致的业务死锁问题

1、问题发现

检查客户数据库的时候发现存在大量死锁的情况

Thread  advanced to log sequence  (LGWR switch)
  Current log#  seq#  mem# : /oradata/oracle/online_log/redo16_01.log
  Current log#  seq#  mem# : /oradata/oracle/online_log/redo16_02.log
Tue Jul  ::
Archived Log entry  added for thread  sequence  ID 0x59dc8ffa dest :
Tue Jul  ::
LNS: Standby redo logfile selected for thread  sequence  for destination LOG_ARCHIVE_DEST_2
Tue Jul  ::
opiodr aborting process unknown ospid () as a result of ORA-
Tue Jul  ::
ORA-: Deadlock detected. More info in file /u01/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_25846.trc.
Tue Jul  ::
ORA-: Deadlock detected. More info in file /u01/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_14067.trc.
Tue Jul  ::
ORA-: Deadlock detected. More info in file /u01/oracle/diag/rdbms/orcl/orcl/trace/orcl_ora_20781.trc.
Tue Jul  ::
Thread  cannot allocate new log, sequence
Private strand flush not complete

查看trace文件orcl_ora_25846.trc结果如下

Deadlock graph:
                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds waits
TX-026e0020-000001a5                X                            S
TM-0007fd6c-                 X                          SX

session : DID --000001FEsession : DID --
session : DID --00000014session : DID --000001FE 

Rows waited on:
  Session : obj - rowid = 0007FD6C - AAAAAAAAAAAAAAAAAA
  (dictionary objn - , file - , block - , slot - )
  Session : no row

----- Information for the OTHER waiting sessions -----
Session :
  sid:  ser:  audsid:  user: /FD14
    flags: (0x45) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40009) -/-/INC
  pid:  O/S info: user: oracle, term: UNKNOWN, ospid:
    image: oracle@dbserver1
  client details:
    O/S info: user: TL3050, term: TL3050-WZ, ospid: :
    machine: WORKGROUP\TL3050-WZ program: CWV4.2.8.337_20131204.exe
    application name: CWV4.2.8.337_20131204.exe, hash value=
  current SQL:
  insert into pzd2018
(UNI_NO,ORD,STYPE,STYPE2,SNO,SYEAR,SMONTH,RMONTH,SDAY,SABSTRACT,OPERATOR,J_AMOUNT,D_AMOUNT,SUBJ,SUBJNAME,
OPP_SUBJ,SRC_CODE,ECO_CODE,SRC_PAYTYPE,SRC_BUTYPE,ECO_TYPE,ECO_WARRANT,PRJ_ORDER,PRJ_NAME,OPP_PRJ,CLR_ORDER,
UNIT_CODE,SPECCODE,CONTRACT_NO,CAR_NO,OLPAY_SNO,schedule_date,WB_TYPE,WB_JNUM,WB_DNUM,WB_FACT,NUM_TYPE,
NUM_JNUM,NUM_DNUM,NUM_PRICE,CAP_NO,CAP_ORD,JSFS_CODE,ZPH,BUSS_DATE,OTHER_UNIT,ACNT,BANKNO,ADDRESS1,ADDRESS2,
TNO,ACT_NO,BU_CODE,T_CODE,RESBU_CODE,RESBU_AMT,SPECCODE1,SPECCODE2,SPECCODE3,SPECCODE4,RES_S1,
RES_S2,RES_S3,RES_S4,ASSET_SUBJ,TAX_NO,SRC_NAME,ADDITION,UNI_PRJ_ORDER,Clr_Bu_Code,
Source_Type,Source,SrKey,SMark,Uni_Prj_Name,clrsno,input_name,check_name,attach_act,
attach_act_no,pz_attr,src_type,zj_type,ref_uni_no,charge_sno,charge_name,src_lkx,order_type,c

----- End of information for the OTHER waiting sessions -----

Information for THIS session:

----- Current SQL Statement for this session (sql_id=9ktt36bsngnyx) -----
insert into pz2018
(UNI_NO,STYPE,STYPE2,SNO,SYEAR,SMONTH,RMONTH,SDAY,INPUT_NAME,CHECK_NAME,COMP_NAME,COMP_NAME2,
ADDITION,CHILDNUM,J_AMOUNT,D_AMOUNT,SSTATE,REMARK,PZ_ATTR)
values(:,:,:,:,:,:,:,:,:,:,:,:,:,:,:,:,:,:,:)
===================================================

2、问题分析

可以看出来241号会话持有一个TM锁，在执行insert into pzd2018语句在等待S锁

4468号会话持有一个TX锁，在执行insert into pz2018语句，在等待SX锁

通过与业务沟通与数据库查询发现了以下的锁表操作，并和业务确定了属于业务SQL

lock table pz2018 in exclusive mode

到这里问题已经清楚了，整个逻辑是这样的

241号会话将pz2018全表排他模式进行了锁定，导致4468会话无法对pz2018表进行insert操作，原因是无法在表上获取共享排它锁即SX锁，导致4468号会话进入等待模式

而4468号会话在等待前进行了insert into pzd2018操作，而241号会话在插入时存在唯一约束，导致241会话进行TX锁等待，等待4468号session数据提交或者回滚

这样一个环状等待就形成了即死锁

等待发生时会话的等待情况

SQL> select a.sample_time,
  2         a.session_id,
  3         a.session_serial#,
  4         a.blocking_session bsession,
  5         a.blocking_session_serial# bserial#,
  6         a.event,
  7         a.machine,
  8         a.module,
  9         a.sql_opname
 10    from dba_hist_active_sess_history a
 11   where a.session_id in (241, 4468, 6819, 10817)
 12     and a.sample_time > to_date('', 'yyyymmddhh24')
 13     and a.sample_time < to_date('', 'yyyymmddhh24')
 14     and a.event is not null
 15   order by a.sample_time
 16  ;
SAMPLE_TIME                    SESSION_ID SESSION_SERIAL#   BSESSION   BSERIAL# EVENT                          MACHINE                        MODULE                         SQL_OPNAME
------------------------------ ---------- --------------- ---------- ---------- ------------------------------ ------------------------------ ------------------------------ ----------------------------------------------------------------
03-7月 -18 10.00.40.857 上午          241             425       6587       7875 enq: TM - contention           WORKGROUP\TL3050-WZ            CWV4.2.8.337_20131204.exe      LOCK TABLE
03-7月 -18 10.49.45.384 上午        10817              97      12929       7665 read by other session          webserver                      JDBC Thin Client               SELECT
03-7月 -18 10.51.16.143 上午          241             425       4468       2029 enq: TX - row lock contention  WORKGROUP\TL3050-WZ            CWV4.2.8.337_20131204.exe      INSERT
03-7月 -18 10.51.16.143 上午         4468            2029        241        425 enq: TM - contention           ZDCW\WANGH88208561             XCV5（新5.24）.exe             INSERT
03-7月 -18 10.52.46.903 上午        10817             121                       null event                     dbserver1                                                     SELECT
03-7月 -18 10.53.57.464 上午         6819              99      10817        133 enq: TX - row lock contention  ZDCW\WANGWD88981612            CWV4.exe                       INSERT
03-7月 -18 10.53.57.464 上午        10817             133       6819         99 enq: TM - contention           ZDCW\WANGH88208561             XCV5（新5.24）.exe             INSERT
03-7月 -18 10.54.07.554 上午        10817             133                       db file parallel read          ZDCW\WANGH88208561             XCV5（新5.24）.exe             INSERT
8 rows selected

3、锁等待的模拟，问题复现

---session1
SQL> lock table pz2018 in exclusive mode;
Table(s) Locked.
----session2
SQL> insert into pzd2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZD_Yong');
1 row created.
SQL> insert into pz2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZ_Yong');
----session2执行直接hang住无法完成，在等待TM锁
SQL> select s.SID,s.BLOCKING_SESSION bsid,s.EVENT,s.MACHINE,s.MODULE,s.STATUS,s.STATE  from  v$session s where s.EVENT is not null and s.STATUS='ACTIVE' and s.WAIT_CLASS<>'Idle';
       SID       BSID EVENT                          MACHINE                        MODULE                                   STATUS   STATE
---------- ---------- ------------------------------ ------------------------------ ---------------------------------------- -------- -------------------
        17        143 enq: TM - contention           172-16-8-110                   SQL*Plus                                 ACTIVE   WAITING
----session1执行
SQL> insert into pzd2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZD_Yong');
--session1 直接hang住，session2抛出错误发现死锁
SQL> insert into pz2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZ_Yong');
insert into pz2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZ_Yong')
*
ERROR at line 1:
ORA-00060: deadlock detected while waiting for resource
----检查数据库等待
SQL> set linesize 1000 pagesize 5000
SQL> col EVENT for a30
SQL> col MACHINE for a30
SQL> col MODULE for a40
SQL> select s.SID,s.BLOCKING_SESSION bsid,s.EVENT,s.MACHINE,s.MODULE,s.STATUS,s.STATE  from  v$session s where s.EVENT is not null and s.STATUS='ACTIVE' and s.WAIT_CLASS<>'Idle';
       SID       BSID EVENT                          MACHINE                        MODULE                                   STATUS   STATE
---------- ---------- ------------------------------ ------------------------------ ---------------------------------------- -------- -------------------
       143         17 enq: TX - row lock contention  172-16-8-110                   SQL*Plus    

查看数据库alert日志发现

Thu Jul 05 11:40:40 2018
ORA-00060: Deadlock detected. More info in file /u01/app/oracle/diag/rdbms/dtstack1/dtstack1/trace/dtstack1_ora_29840.trc.

查看死锁trace

Deadlock graph:
                       ---------Blocker(s)--------  ---------Waiter(s)---------
Resource Name          process session holds waits  process session holds waits
TM-0001554c-00000000        28      17     X             27     143          SX
TX-00040008-000002d9        27     143     X             28      17           S

session 17: DID 0001-001C-00000024      session 143: DID 0001-001B-00000155
session 143: DID 0001-001B-00000155     session 17: DID 0001-001C-00000024 

Rows waited on:
  Session 17: no row
  Session 143: obj - rowid = 0001554C - AAAAAAAAAAAAAAAAAA
  (dictionary objn - 87372, file - 0, block - 0, slot - 0)

----- Information for the OTHER waiting sessions -----
Session 143:
  sid: 143 ser: 905 audsid: 610017 user: 85/DTYONG
    flags: (0x45) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
    flags2: (0x40009) -/-/INC
  pid: 27 O/S info: user: oracle, term: UNKNOWN, ospid: 29846
    image: oracle@172-16-8-110 (TNS V1-V3)
  client details:
    O/S info: user: oracle, term: pts/1, ospid: 29845
    machine: 172-16-8-110 program: sqlplus@172-16-8-110 (TNS V1-V3)
    application name: SQL*Plus, hash value=3669949024
  current SQL:
  insert into pz2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZ_Yong')

----- End of information for the OTHER waiting sessions -----

Information for THIS session:

----- Current SQL Statement for this session (sql_id=7jbgf8fc4cac0) -----
insert into pzd2018(OBJECT_ID,OBJECT_NAME) values(100000000,'PZD_Yong')
===================================================
PROCESS STATE
-------------
Process global information:
     process: 0x914c4ed0, call: 0x910d2008, xact: 0x90390710, curses: 0x916aa020, usrses: 0x916aa020
     in_exception_handler: no
  ----------------------------------------
  SO: 0x914c4ed0, type: 2, owner: (nil), flag: INIT/-/-/0x00 if: 0x3 c: 0x3
   proc=0x914c4ed0, name=process, file=ksu.h LINE:12721, pg=0
  (process) Oracle pid:28, ser:23, calls cur/top: 0x910d2008/0x910d2008
            flags : (0x0) -
            flags2: (0x0),  flags3: (0x10)
            intr error: 0, call error: 0, sess error: 0, txn error 0
            intr queue: empty
    ksudlp FALSE at location: 0
  (post info) last post received: 138 0 2
              last post received-location: ksl2.h LINE:2374 ID:kslpsr
              last process to post me: 0x914b3298 1 6
              last post sent: 0 0 26
              last post sent-location: ksa2.h LINE:285 ID:ksasnd
              last process posted by me: 0x914b3298 1 6
    (latch info) wait_event=0 bits=0x0
    Process Group: DEFAULT, pseudo proc: 0x915515e8
    O/S info: user: oracle, term: UNKNOWN, ospid: 29840
    OSD pid info: Unix process pid: 29840, image: oracle@172-16-8-110 (TNS V1-V3)
    ----------------------------------------
    SO: 0x916aa020, type: 4, owner: 0x914c4ed0, flag: INIT/-/-/0x00 if: 0x3 c: 0x3
     proc=0x914c4ed0, name=session, file=ksu.h LINE:12729, pg=0
    (session) sid: 17 ser: 683 trans: 0x90390710, creator: 0x914c4ed0
              flags: (0x45) USR/- flags_idl: (0x1) BSY/-/-/-/-/-
              flags2: (0x40009) -/-/INC