崩潰恢複（crash recovery）與 AUTORESTART參數，crashautorestart

崩潰恢複（crash recovery）與 AUTORESTART參數，crashautorestart
       關於這個參數設定的影響，在生產系統中經曆過兩次：
       第一次是有套不太重要的系統安裝在虛擬機器，這套系統所有應用（DB2 WAS IHS）都配置到/etc/rc.local中，每次啟動機器會自動拉起應用，然後有次虛擬機器宕機，重啟後檢查了各個應用進程都正常啟動，但是前台頁面訪問異常無法訪問，然後到後台手動串連資料庫報：
SQL1015N  The database is in an inconsistent state.  SQLSTATE=55025
根據SQL1015N提示：需要執行RESTART DATABASE DBNAME命令，執行後然後資料庫可以正常串連

第二次是一套HA伺服器的主機電源故障發生系統切換，切換到備機後，檢查應用都正常被拉起，但是前台無法訪問，和第一次是相同的問題，AUTORESTART參數被設定了OFF

這個參數解釋如下：
       如果DB2資料庫遭受斷電或者異常關閉，資料庫沒有乾淨的關閉，那麼資料庫在啟動的時候將會進行crash recovery. 但是如果資料庫參數AUTORESTART設定為OFF的話，在啟動資料庫後DB2不會進行CRASH RECOVERY。關於crash recovery，在db2diag.log日誌會有相關體現

下面重現這一情境：

/* 1   設定AUTORESTART為OFF   */[db2inst1@limt ~]$ db2 UPDATE DATABASE CONFIGURATION for limtdb USING AUTORESTART OFF IMMEDIATEDB20000I  The UPDATE DATABASE CONFIGURATION command completed successfully.[db2inst1@limt ~]$ db2 get db cfg for limtdb|grep -i AUTORESTART Auto restart enabled                      (AUTORESTART) = OFF [db2inst1@limt yunwei]$ db2 connect to limtdb   Database Connection Information Database server        = DB2/LINUXX8664 10.1.0 SQL authorization ID   = DB2INST1 Local database alias   = LIMTDB/* 2   插入一條資料但不提交，為了資料庫處於不一致性   */[db2inst1@limt yunwei]$ db2  +c "insert into A values(15485,'asdas','asdas')"DB20000I  The SQL command completed successfully.[db2inst1@limt yunwei]$ /* 3  kill資料庫，類比異常宕機情況   */[db2inst1@limt yunwei]$ ps -ef|grep db2sysdb2inst1  5287  5285  1 08:07 pts/1    00:00:04 db2sysc 0                                      db2inst1  5827  3612  0 08:12 pts/1    00:00:00 grep db2sys[db2inst1@limt yunwei]$ kill -9 5287/* 4  啟動資料庫，此時資料庫沒有進行崩潰恢複，因為AUTORESTART為OFF  */[db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ db2start12/19/2014 08:13:04     0   0   SQL1063N  DB2START processing was successful.SQL1063N  DB2START processing was successful.[db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ /* 5  此處報錯是因為剛才的db2bp進程沒有terminate  */[db2inst1@limt yunwei]$ db2 connect to limtdbSQL0752N  Connecting to a database is not permitted within a logical unit of work when the CONNECT type 1 setting is in use.  SQLSTATE=0A001[db2inst1@limt yunwei]$ db2 terminateDB20000I  The TERMINATE command completed successfully./* 6  再次啟動時候報資料庫不一致 */[db2inst1@limt yunwei]$ db2 connect to limtdbSQL1015N  The database is in an inconsistent state.  SQLSTATE=55025/* 7  db2 ? SQL1015N 有一條建議： using the RESTART DATABASE command*/[db2inst1@limt yunwei]$ db2 restart database limtdbDB20000I  The RESTART DATABASE command completed successfully. /* 8  資料庫可以正常串連*/[db2inst1@limt yunwei]$ db2 connect to limtdb   Database Connection Information Database server        = DB2/LINUXX8664 10.1.0 SQL authorization ID   = DB2INST1 Local database alias   = LIMTDB/* 9   以下是設定AUTORESTART為ON情況下，資料庫宕機重啟(不需要執行RESTART DATABASE) */[db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ db2 UPDATE DATABASE CONFIGURATION for limtdb USING AUTORESTART ON IMMEDIATEDB20000I  The UPDATE DATABASE CONFIGURATION command completed successfully.[db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ db2 get db cfg for limtdb|grep -i AUTORESTART Auto restart enabled                      (AUTORESTART) = ON[db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ [db2inst1@limt yunwei]$ db2  +c "insert into A values(15485,'asdas','asdas')"DB20000I  The SQL command completed successfully.[db2inst1@limt yunwei]$ ps -ef|grep db2sysdb2inst1  5870  5868  1 08:13 pts/1    00:00:03 db2sysc 0                                      db2inst1  6122  3612  0 08:16 pts/1    00:00:00 grep db2sys[db2inst1@limt yunwei]$ kill -9 5870[db2inst1@limt yunwei]$ db2start12/19/2014 08:16:35     0   0   SQL1063N  DB2START processing was successful.SQL1063N  DB2START processing was successful.[db2inst1@limt yunwei]$ db2 connect to limtdbSQL0752N  Connecting to a database is not permitted within a logical unit of work when the CONNECT type 1 setting is in use.[db2inst1@limt yunwei]$ db2 terminateDB20000I  The TERMINATE command completed successfully.[db2inst1@limt yunwei]$ db2 connect to limtdb   Database Connection Information Database server        = DB2/LINUXX8664 10.1.0 SQL authorization ID   = DB2INST1 Local database alias   = LIMTDB