[20190416]查看shared latch gets的变化.txt

1.环境:
SYS@book> @ ver1
PORT_STRING                    VERSION        BANNER
------------------------------ -------------- --------------------------------------------------------------------------------
x86_64/Linux 2.4.xx            11.2.0.4.0     Oracle Database 11g Enterprise Edition Release 11.2.0.4.0 - 64bit Production

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        630         69         73              0                0             0                   0          0  541058918

--//补充一点我发现空扫描v$latch也会导致gets的增加.扫描 v$latch_parent不会.

2.测试:
$ cat peek.sh
#! /bib/bash
# 参数如下:latch_name Monitoring_duration
sqlplus -s -l / as sysdba <<EOF
col laddr new_value laddr
SELECT sysdate,addr laddr FROM v\$latch_parent WHERE NAME='$1';
oradebug setmypid
$(seq $2|xargs -I{} echo -e 'oradebug peek 0x&laddr 60\nhost sleep 1' )
EOF
--//修改peek查看的长度60.

$ cat i3.sh
#! /bin/bash
zdate=$(date '+%H%M%S')
echo $zdate
source peek.sh 'gcs partitioned table hash' 36 | timestamp.pl >| /tmp/peeks_${zdate}.txt &
seq 36 | xargs -I{} echo -e 'sqlplus -s -l / as sysdba <<< @latch_free\nsleep 1'  | bash >| /tmp/latch_free_${zdate}.txt &
# 参数如下: @ latch.txt latch_name willing why where mode sleep_num
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 4 5  8 6 > /dev/null &
sleep 2
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 7 8  8 6 > /dev/null &
sleep 2
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 9 10 8 6 > /dev/null &
sleep 2
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 11 12 8 6 > /dev/null &
wait

$ grep  -v '^.*: $' /tmp/peeks_153425.txt | cut -c10- | uniq -c
      1  SYSDATE             LADDR
      1  ------------------- ----------------
      1  2019-04-16 15:34:25 0000000060018A18
      1  Statement processed.
      2  [060018A18, 060018A54) = 00000001 00000000 00000277 00000096 00000006 00000005 00000004 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      2  [060018A18, 060018A54) = 00000002 00000000 00000278 00000096 00000006 00000008 00000007 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      2  [060018A18, 060018A54) = 00000003 00000000 00000279 00000096 00000006 0000000A 00000009 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      2  [060018A18, 060018A54) = 00000003 00000000 0000027A 00000096 00000006 0000000C 0000000B 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      2  [060018A18, 060018A54) = 00000002 00000000 0000027A 00000096 00000006 0000000C 0000000B 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      2  [060018A18, 060018A54) = 00000001 00000000 0000027A 00000096 00000006 0000000C 0000000B 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
     24  [060018A18, 060018A54) = 00000000 00000000 0000027A 00000096 00000006 0000000C 0000000B 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        634         69         73              0                0             0                   0          0  541058918

--//0x27A=634
--//0x277=631
--//0x45=69
--//0x49=73
--//上下对比可以发现MISSES,SLEEPS次数没有变化.gets增加4次.WAIT_TIME的时间也没有变化.

$ cat i4.sh
#! /bin/bash
zdate=$(date '+%H%M%S')
echo $zdate
source peek.sh 'gcs partitioned table hash' 36 | timestamp.pl >| /tmp/peeks_${zdate}.txt &
seq 36 | xargs -I{} echo -e 'sqlplus -s -l / as sysdba <<< @latch_free\nsleep 1'  | bash >| /tmp/latch_free_${zdate}.txt &
# 参数如下: @ latch.txt latch_name willing why where mode sleep_num
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 4 5  x 6 > /dev/null &
sleep 2
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 7 8  s 6 > /dev/null &
sleep 2
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 9 10 s 6 > /dev/null &
sleep 1.9
sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 11 12 s 6 > /dev/null &
wait

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        634         69         73              0                0             0                   0          0  541058918

$ grep  -v '^.*: $' /tmp/peeks_153730.txt | cut -c10- | uniq -c
      1  SYSDATE             LADDR
      1  ------------------- ----------------
      1  2019-04-16 15:37:30 0000000060018A18
      1  Statement processed.
      6  [060018A18, 060018A54) = 00000015 20000000 0000027B 00000096 00000006 00000005 00000004 00000000 00000000 00000045 00000000 00000000 203FE766 00000000 00000049
      6  [060018A18, 060018A54) = 00000001 00000000 0000027C 00000096 00000006 00000008 00000007 00000000 00000000 00000046 00000000 00000000 207CF91C 00000000 0000004A
      6  [060018A18, 060018A54) = 00000001 00000000 0000027D 00000096 00000006 0000000A 00000009 00000000 00000000 00000047 00000000 00000000 20F71FAA 00000000 0000004B
      6  [060018A18, 060018A54) = 00000001 00000000 0000027E 00000096 00000006 0000000C 0000000B 00000000 00000000 00000048 00000000 00000000 21AFED4D 00000000 0000004C
     12  [060018A18, 060018A54) = 00000000 00000000 0000027E 00000096 00000006 0000000C 0000000B 00000000 00000000 00000048 00000000 00000000 21AFED4D 00000000 0000004C

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        638         72         76              0                0             0                   0          0  565177677

--//上下比较,可以发现GETS增加4次,MISSES,SLEEPS增加3次.WAIT_TIME从565177677=>541058918, 相减等于24118759,可以猜测这个单位是微秒.换算后大约24秒.基本符合.
--//也可以发现持有该latch时,gets数量增加.

3.继续测试:
--//如果大量的并发S mode会出现什么情况呢?
$ cat i5.sh
#! /bin/bash
zdate=$(date '+%H%M%S')
echo $zdate
source peek.sh 'gcs partitioned table hash' 10 | timestamp.pl >| /tmp/peeks_${zdate}.txt &
seq 10 | xargs -I{} echo -e 'sqlplus -s -l / as sysdba <<< @latch_free\nsleep 1'  | bash >| /tmp/latch_free_${zdate}.txt &
# 参数如下: @ latch.txt latch_name willing why where mode sleep_num
sleep 1
seq 100 | xargs -I {} -P 100 sqlplus /nolog @ shared_latch.txt 'gcs partitioned table hash' 1 4 {}  s 6 > /dev/null
wait
--//100个会话并发的情况呢?

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        840         73         76              0                0             0                   0          1  565177677

$ grep  -v '^.*: $' /tmp/peeks_155301.txt | cut -c10- | uniq -c
      1  SYSDATE             LADDR
      1  ------------------- ----------------
      1  2019-04-16 15:53:01 0000000060018A18
      1  Statement processed.
      2  [060018A18, 060018A54) = 00000000 00000000 00000348 00000096 00000006 00000055 00000004 00000000 00000000 00000049 00000000 00000000 21AFED4D 00000000 0000004C
      6  [060018A18, 060018A54) = 00000064 00000000 000003AC 00000096 00000006 0000001C 00000004 00000000 00000000 0000004C 00000000 00000000 21AFED4D 00000000 0000004C
      2  [060018A18, 060018A54) = 00000000 00000000 000003AC 00000096 00000006 0000001C 00000004 00000000 00000000 0000004C 00000000 00000000 21AFED4D 00000000 0000004C

SYS@book> select addr,name,level#,GETS,MISSES,SLEEPS,IMMEDIATE_GETS,IMMEDIATE_MISSES,WAITERS_WOKEN,WAITS_HOLDING_LATCH,SPIN_GETS,WAIT_TIME from v$latch_parent where lower(name) like '%'||lower('&&1')||'%';
ADDR             NAME                                         LEVEL#       GETS     MISSES     SLEEPS IMMEDIATE_GETS IMMEDIATE_MISSES WAITERS_WOKEN WAITS_HOLDING_LATCH  SPIN_GETS  WAIT_TIME
---------------- ---------------------------------------- ---------- ---------- ---------- ---------- -------------- ---------------- ------------- ------------------- ---------- ----------
0000000060018A18 gcs partitioned table hash                        6        940         76         76              0                0             0                   0          4  565177677

--//没有问题计数正确!!没有丢失.
--//0x21AFED4D=565177677,对应的是wait_time总和.

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