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题目部分
在Oracle中,Oracle 10g和11g告警日志文件的位置在哪里?
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答案部分
作为一名DBA,必须知道告警日志是什么,在何处。实时的监控数据库的告警日志是必须进行的工作。监控并且根据不同的告警级别,通过邮件或短信发送告警信息给DBA,这可以帮助DBA及时了解数据库的变化与异常,及时响应并介入处理。
告警日志文件有2种类型,一种是纯文本格式的,另外一种是xml文件格式的,平时查看最多地是纯文本格式的告警日志。告警日志的内容包含:消息和错误的类型、ORA-600内部错误、ORA-1578块损坏错误、ORA-12012作业队列错误、实例启动关闭,恢复等信息、特定的DDL命令、影响表空间,数据文件及回滚段的命令、可持续的命令被挂起、LGWR不能写入到日志文件、归档进程启动信息、调度进程的相关信息和动态参数的修改信息等。
无论是Oracle 10g还是11g,其告警日志的位置都可以由参数BACKGROUND_DUMP_DEST来查询,只不过在Oracle 11g中位置有所变化。在Oracle 10g中,告警日志一般在$ORACLE_BASE/admin/$ORACLE_SID/bdump目录下:
SYS@lhrdb> SHOW PARAMETER BACKGROUND_DUMP_DEST
NAME TYPE VALUE
------------------------------------ ----------- ------------------------------
background_dump_dest string /u01/app/oracle/admin/lhrdb/bdump
在Oracle 11g中,告警日志一般在$ORACLE_BASE/diag/rdbms/$DBNAME/$ORACLE_SID/trace目录下:
SYS@lhrdb> SHOW PARAMETER BACKGROUND_DUMP_DEST
NAME TYPE VALUE
------------------------------------ ---------------------- ------------------------------
background_dump_dest string /oracle/app/oracle/diag/rdbms/lhrdb/lhrdb/trace
[ZFZHLHRDB1:oracle]:/oracle>cd /oracle/app/oracle/diag/rdbms/lhrdb/lhrdb/trace
[ZFZHLHRDB1:oracle]:/oracle/app/oracle/diag/rdbms/lhrdb/lhrdb/trace>ls -l alert*
-rw-r----- 1 oracle asmadmin 13852942 Oct 17 13:22 alert_lhrdb.log
从Oracle 12.1.0.1开始,参数BACKGROUND_DUMP_DEST已废弃,告警日志的位置应该由以下SQL来查询:
SQL> SELECT d.VALUE FROM V$DIAG_INFO d WHERE d.NAME='Diag Trace';
VALUE
---------------------------------------------------------
/u01/app/oracle/diag/rdbms/lhrdb/lhrdb/trace
需要注意的是,该SQL也适用于Oracle 11g的版本。
由于告警日志按时间的先后顺序不断累积存储,久而久之,势必造成告警日志的过大,难以维护,查找相关的信息也不方便。另外,若告警日志超大,也会严重影响系统的性能。这里提供3种办法来管理告警日志:①使用外部表方式来管理告警日志将大大简化维护工作量,也可以更直关的获取所需的信息。②视图V$DIAG_ALERT_EXT对应的基表里存储了告警日志的内容,可以根据该视图将告警日志的内容存储在历史表中。③利用SHELL脚本定时将告警日志进行备份,防止告警日志过大而影响系统性能。
1.外部表管理告警日志的脚本如下所示:
drop directory DIR_ALERT;
create directory DIR_ALERT as '/u01/app/oracle/diag/rdbms/orclasm/orclasm/trace';
drop table alert_log;
create table alert_log(
text varchar2(500)
)organization external
(type oracle_loader
default directory DIR_ALERT
access parameters
(records delimited by newline
)location('alert_orclasm.log')
) reject limit unlimited;
select * from alert_log where text like 'ORA-%';
查看最新的10条告警日志记录:
select * from (
select rownum rn,a.text from alert_log a) b where b.rn>=(select count(1)-10 from alert_log a);
看最新的10条ORA告警日志记录:
SELECT *
FROM (SELECT rownum rn,
a.text
FROM alert_log a
WHERE a.text LIKE 'ORA-%') b
WHERE b.rn >=
(SELECT COUNT(1) - 10 FROM alert_log a WHERE a.text LIKE 'ORA-%');
--2.利用V$DIAG_ALERT_EXT记录历史告警日志的脚本如下所示:
---drop table XB_ALERTLOG_ALL_LHR ;
create table XB_ALERTLOG_ALL_LHR
(
ID NUMBER primary key,
alert_date date,
message_text VARCHAR2(3000),
message_type NUMBER,
message_level NUMBER,
message_id VARCHAR2(67),
message_group VARCHAR2(67),
detailed_location VARCHAR2(163),
problem_key VARCHAR2(67),
record_id NUMBER,
organization_id VARCHAR2(67),
component_id VARCHAR2(67),
host_id VARCHAR2(67),
host_address VARCHAR2(49),
client_id VARCHAR2(67),
module_id VARCHAR2(67),
process_id VARCHAR2(35)
) nologging
partition by range(alert_date)
interval(numtoyminterval(1,'month'))
(partition P201406 VALUES LESS THAN(TO_DATE('201407','YYYYMM')));
--drop SEQUENCE S_XB_SQL_MONITOR_LHR;
CREATE SEQUENCE S_XB_ALERTLOG_ALL_LHR START WITH 1 INCREMENT BY 1 cache 20;
create index ind_ALERTLOG_ALL_In_Date on XB_ALERTLOG_ALL_LHR(ALERT_DATE,Record_Id) local nologging;
---------记录历史告警日志
CREATE PROCEDURE p_alert_log_lhr AS
v_max_recordid NUMBER;
v_max_date DATE;
BEGIN
SELECT MAX(a.record_id),
MAX(a.alert_date)
INTO v_max_recordid,
v_max_date
FROM XB_ALERTLOG_ALL_LHR a
WHERE a.alert_date >= SYSDATE - 360 / 1440 --3h'之前
AND a.alert_date <= SYSDATE;
INSERT INTO XB_ALERTLOG_ALL_LHR nologging
(ID,
ALERT_DATE,
MESSAGE_TEXT,
MESSAGE_TYPE,
MESSAGE_LEVEL,
MESSAGE_ID,
MESSAGE_GROUP,
DETAILED_LOCATION,
PROBLEM_KEY,
RECORD_ID,
ORGANIZATION_ID,
COMPONENT_ID,
HOST_ID,
HOST_ADDRESS,
CLIENT_ID,
MODULE_ID,
PROCESS_ID)
SELECT s_XB_ALERTLOG_ALL_LHR.Nextval,
to_date(to_char(a.ORIGINATING_TIMESTAMP,
'YYYY-MM-DD HH24:MI:SS'),
'YYYY-MM-DD HH24:MI:SS') alert_date,
a.MESSAGE_TEXT,
a.MESSAGE_TYPE,
a.MESSAGE_LEVEL,
a.MESSAGE_ID,
a.MESSAGE_GROUP,
a.DETAILED_LOCATION,
a.PROBLEM_KEY,
a.RECORD_ID,
a.ORGANIZATION_ID,
a.COMPONENT_ID,
a.HOST_ID,
a.HOST_ADDRESS,
a.CLIENT_ID,
a.MODULE_ID,
a.PROCESS_ID
FROM v$diag_alert_ext a
WHERE a.COMPONENT_ID = 'rdbms'
AND a.FILENAME LIKE
'/u01/app/oracle/diag/rdbms/orclasm/orclasm/alert/log.xml%'
AND a.RECORD_ID > v_max_recordid
AND a.ORIGINATING_TIMESTAMP >= v_max_date;
COMMIT;
END p_alert_log_lhr;
/
--定时任务:
BEGIN
DBMS_SCHEDULER.CREATE_JOB(JOB_NAME => 'job_p_alert_log_lhr',
JOB_TYPE => 'STORED_PROCEDURE',
JOB_ACTION => 'p_alert_log_lhr',
ENABLED => TRUE,
START_DATE => SYSDATE,
comments => '记录历史告警日志,每2个小时执行一次');
END;
/
3.利用SHELL脚本定时将告警日志进行备份
利用Linux下的crontab设置每周日早上凌晨归档一次告警日志:
[oracle@rhel6lhr ~]$ crontab -l
2 12 * * 1 /home/oracle/lhr/alert_log_archive.sh
[oracle@rhel6lhr ~]$ more /home/oracle/lhr/alert_log_archive.sh
#*************************************************************************
# FileName :alert_log_archive.sh
#*************************************************************************
# Author :lhr
# CreateDate :2014-07-16
# blogs :http://blog.itpub.net/26736162
# Description :this script is made the alert log archived every day
# crontab : 2 0 * * 0 /home/oracle/lhr/alert_log_archive.sh ---sunday exec
#*************************************************************************
#! /bin/bash
# these solved the oracle variable problem.
export ORACLE_SID=orclasm
export ORACLE_BASE=/u01/app/oracle
mydate=`date +'%Y%m%d%H%M%S'`
alert_log_path="$ORACLE_BASE/diag/rdbms/$ORACLE_SID/$ORACLE_SID/trace/"
alert_log_file="alert_$ORACLE_SID.log"
alert_arc_file="alert_$ORACLE_SID.log""."${mydate}
cd ${alert_log_path};
if [ ! -e "${alert_log_file}" ]; then
echo "the alert log didn't exits, please check file path is correct!";
exit;
fi
if [ -e ${alert_arc_file} ];then
echo "the alert log file have been archived!"
else
mv ${alert_log_file} ${alert_arc_file}
cat /dev/null > ${alert_log_file}
fi
& 说明:
有关告警日志的更多内容可以参考我的BLOG:http://blog.itpub.net/26736162/viewspace-1221559/
本文选自《Oracle程序员面试笔试宝典》,作者:李华荣。