關於oracle裡的process總結(45天)
阿新 • • 發佈:2022-05-04
感覺需要對process做一個簡單的總結。準備瞭如下的測試場景。
session在服務端請求
先用sqlplus / as sysdba在服務端登入。
SQL> show user
USER is "SYS"
得到當前的session為5860.
SQL> select sid from v$mystat where rownum<2;
SID
----------
5860
得到對應的Process。這個其實就是客戶端對應的process,因為是從服務端登入,所以在服務端應該會有兩個process來對應,一個相當於客戶端,一個相當於服務端。paddr是process對應的記憶體地址,在查詢v$process的很有用。
SQL> select sid,username,process,paddr from v$session where sid=5860;
SID USERNAME PROCESS PADDR
---------- ------------------------------ ------------------------ ----------------
5860 SYS 28490 000000035977B488
SQL> host ps -ef|grep 28490
oratestdb 6741 28490 0 14:48 pts/1 00:00:00 /bin/bash -c ps -ef|grep 28490
oratestdb 6743 6741 0 14:48 pts/1 00:00:00 grep 28490
oratestdb 28490 4017 0 14:45 pts/1 00:00:00 sqlplus as sysdba
oratestdb 28491 28490 0 14:45 ? 00:00:00 oraclePETtest1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
SQL> select pid,spid from v$process where addr='000000035977B488';
PID SPID
---------- ------------------------
31 28491
SQL> host ps -ef|grep 28491
oratestdb 14578 28490 0 14:50 pts/1 00:00:00 /bin/bash -c ps -ef|grep 28491
oratestdb 14580 14578 0 14:50 pts/1 00:00:00 grep 28491
oratestdb 28491 28490 0 14:45 ? 00:00:00 oraclePETtest1 (DESCRIPTION=(LOCAL=YES)(ADDRESS=(PROTOCOL=beq)))
再來看另外一個場景。
session在客戶端請求
通過sqlplus從客戶端登陸。
#############
select sid from v$mystat where rownum<2;
SID
----------
6049
select sid,username,process,paddr from v$session where sid=6049
SQL> /
可以看到對應的Process是824. 這個就是客戶端所在的機器對應的process。
SID USERNAME PROCESS PADDR
---------- ------------------------------ ------------------------ ----------------
6049 JIANRONG
824
000000035977C508
SQL> host ps -ef|grep 824
oraccbs1 824 30352 0 17:05 pts/1 00:00:00 sqlplus
root 3824 3051 0 2013 ? 00:00:00 [aio/29]
oraccbs1 11079 824 0 17:06 pts/1 00:00:00 /bin/bash -c ps -ef|grep 824
oraccbs1 11082 11079 0 17:06 pts/1 00:00:00 grep 824
檢視服務端對應的程序,是17175
SQL> select pid,spid ,username from v$process where addr='000000035977C508';
PID SPID USERNAME
---------- ------------------------ ---------------
32
17175
oratestdb
登入服務端,檢視程序情況,與客戶端的場景不同的是,17175的父程序是1,為root根程序。
oratestdb@ccbdbpt4:/opt/app/oracle/dbtestspt1/oratestdb> ps -ef|grep 17175
oratestdb 17175 1 0 17:05 ? 00:00:00 oraclePETtest1 (LOCAL=NO)
oratestdb 27196 24714 0 17:07 pts/1 00:00:00 grep 17175
對於客戶端場景和服務端場景來說,如果一定要刨根問底的看某個session(比如 session 824)的父程序情況。可以看到最終的process 父程序還是1.
oratest1@:/opt/app/oracle/dbtestpt1/oratest1> ps -ef|grep 30352
oratest1 824 30352 0 17:05 pts/1 00:00:00 sqlplus
oratest1 20500 20060 0 17:23 pts/1 00:00:00 grep 30352
oratest1 30352 30347 0 16:34 pts/1 00:00:00 -bash
oratest1@:/opt/app/oracle/dbtestpt1/oratest1> ps -ef|grep 30347
oratest1 21993 20060 0 17:23 pts/1 00:00:00 grep 30347
oratest1 30347 29705 0 16:34 ? 00:00:00 sshd: oratest1@pts/1
oratest1 30352 30347 0 16:34 pts/1 00:00:00 -bash
oratest1@:/opt/app/oracle/dbtestpt1/oratest1> ps -ef|grep 29705
oratest1 23945 20060 0 17:23 pts/1 00:00:00 grep 29705
root 29705 25298 0 16:34 ? 00:00:00 sshd: oratest1 [priv]
oratest1 30347 29705 0 16:34 ? 00:00:00 sshd: oratest1@pts/1
oratest1@:/opt/app/oracle/dbtestpt1/oratest1> ps -ef|grep 25298
root 25298 1 0 2013 ? 00:00:03 /usr/sbin/sshd
oratest1 26659 20060 0 17:24 pts/1 00:00:00 grep 25298
root 29705 25298 0 16:34 ? 00:00:00 sshd: oratest1 [priv]