互联网公司真的不用oracle数据库吗?

互联网公司不使用oracle数据库这个印象对很多同学来说是有点深的;为了打破这个错误印象,老刘根据维基百科上的世界上最大的前20家互联网公司列表做了梳理,其中14家有使用oracle数据库技术占70%,其中5家使用了Exadata一体机占25%,其中5家为重度使用占25%。 ​​​​比较典型的互联网公司例如facebook,其实一直在使用oracle。Apple苹果因为不算互联网公司,所以不列在其中,但其也较为重度使用oracle。

 

持续更新地址: https://github.com/macleanliu/askRDBMS/blob/master/top-oracle-internet-user.md

 

 

MySQL 5.7在Ubuntu 18.04上重新初始化mysqld –initialize mysqld: Can’t create directory (Errcode: 13 – Permission denied)

注意在ubuntu上mysqld –initialize ,要配置apparmor,可以通过修改参数文件 vim /etc/apparmor.d/usr.sbin.mysqld, 也可以像我一样直接禁用mysql的apparmor profile。

否则会出现 Can’t create directory (Errcode: 13 – Permission denied) 错误

 

su -  root


systemctl stop mysql

 
mkdir -p /d01/mysql 


#这里重新初始化的目标目录是/d01/mysql


chown mysql:mysql /d01
chown mysql:mysql /d01/mysql 


#一些权限设置
mkdir /var/run/mysqld
chown mysql:mysql /var/run/mysqld
chown mysql:mysql /var/log/mysql
chown mysql:mysql /var/log/mysql/*

修改 /etc/mysql/mysql.conf.d/mysqld.cnf

 
datadir         = /d01/mysql


下面 禁用mysql的apparmor profile

aa-status |grep mysql
ln -s /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable/
apparmor_parser -R /etc/apparmor.d/usr.sbin.mysqld



重启 apparmor

 systemctl restart apparmor

aa-status |grep mysql

//aa-status |grep mysql 应当无结果



mysqld --initialize --user=mysql




root@vultr:~# grep password  /var/log/mysql/error.log 
2020-04-27T07:39:28.126296Z 1 [Warning] root@localhost is created with an empty password ! Please consider switching off the --initialize-insecure option.
2020-04-27T07:39:32.229124Z 0 [Note] Shutting down plugin 'sha256_password'
2020-04-27T07:39:32.229128Z 0 [Note] Shutting down plugin 'mysql_native_password'
2020-04-27T07:39:44.435551Z 0 [Note] Shutting down plugin 'sha256_password'
2020-04-27T07:39:44.435556Z 0 [Note] Shutting down plugin 'mysql_native_password'
2020-04-27T07:41:01.360902Z 1 [Note] A temporary password is generated for root@localhost: T#jTiKh+d9Og


临时密码T#jTiKh+d9Og

systemctl start mysql 

mysql -uroot -pT#jTiKh+d9Og
 



MySQL 5.7在Ubuntu 18.04上快速安装 不依赖于APT源脚本

wget https://www.dropbox.com/s/uvmtsd1lqpoju8l/libaio1_0.3.112-5_amd64.deb
wget https://www.dropbox.com/s/tiwi2qhhptpgljm/libmecab2_0.996-6_amd64.deb
wget https://www.dropbox.com/s/nem5b480tckdxx9/libssl1.1_1.1.1c-1ubuntu4_amd64.deb
wget https://www.dropbox.com/s/vrzyqn140cfz77k/mysql-server_5.7.29-1ubuntu18.04_amd64.deb-bundle.tar

tar -xvf mysql-server*.tar
dpkg -i libaio1_0.3.112-5_amd64.deb
dpkg -i libmecab2_0.996-6_amd64.deb 
dpkg -i libssl1.1_1.1.1c-1ubuntu4_amd64.deb
# touch /etc/mysql/my.cnf.fallback
dpkg -i mysql-common_*.deb
dpkg -i mysql-community-client*
dpkg -i mysql-client*
dpkg-preconfigure mysql-community-server_*
dpkg -i mysql-community-server*

MySQL 5.7在Ubuntu 18.04上移动数据文件目录DATADIR

注意由于apparmor的存在,以及mysql-systemd-start脚本的影响,导致在Ubuntu上移动MYSQL DATADIR有一些小问题。

 


步骤0 创建目标目录; 移动数据文件目录,常见的原因有 移动数据到新磁盘或逻辑卷等


例如目标目录路径是 /m01/mysql

mkdir -p /m01/mysql
chown mysql:mysql /m01
chown mysql:mysql /m01/mysql






步骤1 确认datadir

su - root 

mysql -u root -p

select @@datadir;
+-----------------+
| @@datadir       |
+-----------------+
| /var/lib/mysql/ |
+-----------------+
1 row in set (0.00 sec)


关闭MYSQL实例守护进程

systemctl stop mysql

确认状态

systemctl status mysql




步骤2 同步数据文件到新目录 


rsync -av /var/lib/mysql /m01


将原目录归档为备份

mv /var/lib/mysql /var/lib/mysql.bak



步骤3 对/etc/mysql/mysql.conf.d/mysqld.cnf参数文件修改datadir 参数 


vi /etc/mysql/mysql.conf.d/mysqld.cnf

修改datadir参数为

datadir         = /m01/mysql



步骤4 禁用apparmor 的mysql profile



aa-status |grep mysql
ln -s /etc/apparmor.d/usr.sbin.mysqld /etc/apparmor.d/disable/
apparmor_parser -R /etc/apparmor.d/usr.sbin.mysqld



重启 apparmor

 systemctl restart apparmor

aa-status |grep mysql

//aa-status |grep mysql 应当无结果


步骤5  针对mysql-systemd-start中的默认路径问题 创建原目录 

mkdir /var/lib/mysql/mysql -p


步骤6 重启mysql实例

systemctl start mysql
systemctl status mysql

mysql -u root -p

确认datadir

select @@datadir;

 

 

oracle rac 12.1以后的脑裂brain split evict踢节点算法改进

oracle 12.1以后RAC发生脑裂时踢节点的算法变了;以前2节点RAC情况下,总是踢不是lower node number(master node)的那个节点;这样一般就是踢2号节点。在12.1以后clusterware维护一个weight权重值,主要是计算每个节点或者说子集群里使用的service和连接这些service的负载情况,这样当发生脑裂时总是踢weight小的节点,即负载轻的节点,保证服务更多用户的节点存活。 具体可以见 文档  12c: Which Node Will Survive when Split Brain Takes Place (Doc ID 1951726.1) 和 Split Brain: What’s new in Oracle Database 12.1.0.2c?   

 

理解 12.1.0.2 开始,脑裂问题发生后,节点保留策略。

在 11.2 及早期版本,在脑裂发生时,节点号小的会保留下来。然而从 12.1.0.2 开始,引入节点权重的概念。从 12.1.0.2 开始,解决脑裂时,权重高的节点将会存活下来。

 

 

这里负责计算 权重weigth的函数是 clssnmrCheckNodeWeight  , clssnm 即 Node Monitoring (clssnm.c) – Node monitoring (NM) is used to verify the health of all members of the cluster. It will maintain consistency with vendor clusterware (if it exists) via skgxn.

 

12c: Which Node Will Survive when Split Brain Takes Place (Doc ID 1951726.1)

 

PURPOSE
To understand the new behavior, from 12.1.0.2, of which node will survive when split brain takes place.

DETAILS
In 11.2 or even older version, the lowest number node will survive when split brain takes place, however this has changed in 12.1.0.2 with the introduction of node weight. Started from 12.1.0.2, during split brain resolution, node with higher weight will survive:

2014-11-24 14:25:41.140603 : CSSD:1117321536: clssnmrCheckNodeWeight: node(1) has weight stamp(0), pebble(0)
2014-11-24 14:25:41.140609 : CSSD:1117321536: clssnmrCheckNodeWeight: node(2) has weight stamp(311972654), pebble(3)
2014-11-24 14:25:41.140612 : CSSD:1117321536: clssnmrCheckNodeWeight: stamp(311972654), completed(1/2)
2014-11-24 14:25:41.140615 : CSSD:1117321536: clssnmrCheckSplit: Waiting for node weights, stamp(311972654)
2014-11-24 14:25:41.188880 : CSSD:1084811584: clssnmvDiskKillCheck: not evicted, file /dev/raw/raw2 flags 0x00000000, kill block unique 0, my unique 1416805718
2014-11-24 14:25:41.558921 : CSSD:1114167616: clssnmvDiskPing: Writing with status 0x3, timestamp 1416810341/1022717334
2014-11-24 14:25:41.731912 : CSSD:1086388544: clssnmvDHBValidateNCopy: node 1, node1, has a disk HB, but no network HB, DHB has rcfg 311972655, wrtcnt, 9527468, LATS 102 2717514, lastSeqNo 9527467, uniqueness 1416808381, timestamp 1416810341/1022722074
2014-11-24 14:25:41.731928 : CSSD:1086388544: clssnmvReadDskHeartbeat: manual shutdown of nodename node1, nodenum 1 epoch 1416810341 msec 1022722074
2014-11-24 14:25:41.732266 : CSSD:1117321536: clssnmrCheckNodeWeight: node(2) has weight stamp(311972654), pebble(3)
2014-11-24 14:25:41.732273 : CSSD:1117321536: clssnmrCheckNodeWeight: stamp(311972654), completed(1/1)
2014-11-24 14:25:41.732294 : CSSD:1117321536: clssnmCheckDskInfo: My cohort: 2
2014-11-24 14:25:41.732299 : CSSD:1117321536: clssnmRemove: Start
2014-11-24 14:25:41.732306 : CSSD:1117321536: (:CSSNM00007:)clssnmrRemoveNode: Evicting node 1, node1, from the cluster in incarnation 311972655, node birth incarnation 311972654, death incarnation 311972655, stateflags 0x225000 uniqueness value 1416808381 The number of the resource executing on each node and others are considered by the weight. Reference

RHEL 7.4装Oracle 11.2.0.4 RAC的一些问题

cat /etc/redhat-release
Red Hat Enterprise Linux Server release 7.4 (Maipo)

 

一、要安装compat-libcap1.x86_64包:

yum install compat-libcap1.x86_64

否则root.sh会因为缺少库文件而报错

clscfg.bin: error while loading shared libraries: libcap.so.1: cannot open shared object file: No such file or directory Failed to create keys in the OLR, rc = 127, Message:

Failed to write the checkpoint:” with status:FAIL.Error code is 256

 

二、 在执行root.sh前要给GRID_HOME打补丁 ,补丁号18370031 否则因为RHEL 7修改了一些RC脚本会导致安装不上

报错如下:

 

The following environment variables are set as:
ORACLE_OWNER= oracle
ORACLE_HOME=  /u01/app/11.2.0/grid
 
Enter the full pathname of the local bin directory: [/usr/local/bin]:
The contents of “dbhome” have not changed. No need to overwrite.
The contents of “oraenv” have not changed. No need to overwrite.
The contents of “coraenv” have not changed. No need to overwrite.
 
Creating /etc/oratab file…
Entries will be added to the /etc/oratab file as needed by
Database Configuration Assistant when a database is created
Finished running generic part of root script.
Now product-specific root actions will be performed.
Using configuration parameter file: /u01/app/11.2.0/grid/crs/install/crsconfig_params
Creating trace directory
User ignored Prerequisites during installation
Installing Trace File Analyzer
OLR initialization – successful
root wallet
root wallet cert
root cert export
peer wallet
profile reader wallet
pa wallet
peer wallet keys
pa wallet keys
peer cert request
pa cert request
peer cert
pa cert
peer root cert TP
profile reader root cert TP
pa root cert TP
peer pa cert TP
pa peer cert TP
profile reader pa cert TP
profile reader peer cert TP
peer user cert
pa user cert
Adding Clusterware entries to inittab
ohasd failed to start
Failed to start the Clusterware. Last 20 lines of the alert log follow:
2018-03-08 10:20:24.544:
[client(17856)]CRS-2101:The OLR was formatted using version 3.

 

因为补丁18370031(Patch 18370031: RC SCRIPTS (/ETC/RC.D/RC.* , /ETC/INIT.D/* ) ON OL7 FOR CLUSTERWARE)   被 20433339( Patch 24333766: MERGE REQUEST ON TOP OF 11.2.0.4.0 FOR BUGS 18370031 20954311)
包含了, 所以目前应该只能下载到20433339了。

 

 

 

opatch napply -local 20433339



opatch lsinventory
Oracle Interim Patch Installer version 11.2.0.3.23
Copyright (c) 2020, Oracle Corporation.  All rights reserved.


Oracle Home       : /u01/app/11.2.0/grid
Central Inventory : /u01/app/oraInventory
   from           : /u01/app/11.2.0/grid/oraInst.loc
OPatch version    : 11.2.0.3.23
OUI version       : 11.2.0.4.0
Log file location : /u01/app/11.2.0/grid/cfgtoollogs/opatch/opatch2020-03-06_09-37-02AM_1.log

Lsinventory Output file location : /u01/app/11.2.0/grid/cfgtoollogs/opatch/lsinv/lsinventory2020-03-06_09-37-02AM.txt
--------------------------------------------------------------------------------
Local Machine Information::
Hostname: rac1
ARU platform id: 226
ARU platform description:: Linux x86-64

Installed Top-level Products (1): 

Oracle Grid Infrastructure 11g                                       11.2.0.4.0
There are 1 products installed in this Oracle Home.


Interim patches (1) :

Patch  24333766     : applied on Fri Mar 06 08:15:04 EST 2020
Unique Patch ID:  20433339
Patch description:  "OCW Interim patch for 24333766"
   Created on 30 Nov 2016, 12:56:34 hrs PST8PDT
   Bugs fixed:
     18370031, 20954311



--------------------------------------------------------------------------------

OPatch succeeded.

 

但是注意要打以上补丁先要将Opatch升级到最新,所以要安装前先去support.oracle.com下载2个包p6880880_112000_Linux-x86-64.zip和p24333766_112040_Linux-x86-64.zip。

三、安装fuser 命令

yum install psmisc

 

 

四、对于RHEL 7下的udev配置可以看这篇文章 https://gruffdba.wordpress.com/2017/02/20/udev-rules-for-asm-disks-on-rhel7/

这里顺便贴出来:

 

 

 

On this blog and elsewhere you will find UDEV rules examples for setting device ownership and naming consistency on older versions of Linux.

With RHEL7 some of the syntax has changed slightly.

This example was created using OEL7 with the Red Hat kernel, but should also work on Red Hat and CentOS.


First, log in as root and check the block device is visible on the Linux host:

[root@unirac02 ~]# ls /dev/sd*
/dev/sda /dev/sda1 /dev/sda2 /dev/sdb /dev/sdb1
In this example I have created a device sdb, and as you can see I have created a partition header on it.

Next, make sure we can see the device’s SCSI ID:

[root@unirac02 ~]# /lib/udev/scsi_id -g -u /dev/sdb
36006016004503e0017f99d58603c7c1e
Next, we are going to create a UDEV rule for this SCSI ID in the file /etc/udev/rules.d/99-oracleasm.rules.

[root@unirac01 ~]# cat /etc/udev/rules.d/99-oracleasm.rules
KERNEL=="sd?", ENV{ID_SERIAL}=="36006016004503e0017f99d58603c7c1e", SYMLINK+="oracleasm/grid1", OWNER="oracle", GROUP="oinstall", MODE="0660"
If you have several devices to add, you can use the following script to automate the rule generation.

[root@unirac02 ~]# mydevs="sdb sdc sdd" ; export count=0 ; for mydev in $mydevs; do ((count+=1)) ; /lib/udev/scsi_id -g -u /dev/$mydev | awk '{print "KERNEL==\"sd?\", ENV{ID_SERIAL}==\""$1"\", SYMLINK+=\"oracleasm/disk"ENVIRON["count"]"\", OWNER=\"oracle\", GROUP=\"oinstall\", MODE=\"0660\""}' ; done
KERNEL=="sd?", ENV{ID_SERIAL}=="36006016004503e0017f99d58603c7c1e", SYMLINK+="oracleasm/disk1", OWNER="oracle", GROUP="oinstall", MODE="0660"
KERNEL=="sd?", ENV{ID_SERIAL}=="36006016004503e0017f99d58603d1a87", SYMLINK+="oracleasm/disk2", OWNER="oracle", GROUP="oinstall", MODE="0660"
KERNEL=="sd?", ENV{ID_SERIAL}=="36006016004503e0017f99d58603d246a", SYMLINK+="oracleasm/disk3", OWNER="oracle", GROUP="oinstall", MODE="0660"
With RHEL7, restarting the UDEV rules is slightly difference than previous releases:

[root@unirac02 ~]# /sbin/udevadm control --reload-rules
[root@unirac02 ~]# /sbin/udevadm trigger
Now check, and a new device should be visible under /dev/oracleasm

[root@unirac02 ~]# ls -al /dev/oracleasm/*
lrwxrwxrwx. 1 root root 6 Feb 20 18:38 /dev/oracleasm/grid1 -> ../sdb


一些相关文档:

 

Requirements for Installing Oracle 11.2.0.4 RDBMS on OL7 or RHEL7 64-bit (x86-64) (Doc ID 1962100.1)

 

APPLIES TO:

Oracle Database – Standard Edition – Version 11.2.0.4 to 11.2.0.4 [Release 11.2]
Oracle Database – Enterprise Edition – Version 11.2.0.4 to 11.2.0.4 [Release 11.2]
Oracle Database Cloud Schema Service – Version N/A and later
Oracle Database Exadata Cloud Machine – Version N/A and later
Oracle Cloud Infrastructure – Database Service – Version N/A and later
Linux x86-64

PURPOSE

This note explains the requirements that need to be met for a successful installation of Oracle 11gR2 RDBMS release 11.2.0.4 on Red Hat Enterprise Linux 7.0 (or higher 7.x version), 64-bit (x86-64).  These guidelines apply to cluster (RAC) or standalone / single instances.

It is NOT the purpose of this NOTE to repeat every “how-to” step that is presented in the 11gR2 Installation Guide manual. For example this NOTE does not include how to create the Linux OS account named “oracle”, nor does it cover how to set environment variables. Both are adequately covered in Chapter 2 “Oracle Database Pre-installation Requirements” of the 11gR2 Installation Guide manual.

You can download Oracle 11.2.0.4 software from My Oracle Support (patch 13390677)

SCOPE

This procedure is meant for those planning/installing Oracle 11gR2 RDBMS release 11.2.0.4.0 (or higher 11.2.0.x version) on Red Hat Enterprise Linux 7.0 (or higher 7.x version) on the 64-bit (x86-64) platform. Since it is the expressed goal to keep Oracle Linux (OL) functionally IDENTICAL to RHEL, this NOTE is also completely applicable to 64-bit (x86-64) OL 7.0 (or higher 7.x version).

This procedure is not meant for those planning/installing Grid Infrastructure (GI) or any other Oracle products.

DETAILS

Requirements for installing Oracle 11gR2 RDBMS release 11.2.0.4 64-bit on RHEL7 or OL7 64-bit (x86_64)

I. Hardware:
===========
1. Minimum Hardware Requirements
a.) At least 1.0 GB (1024MB) of physical RAM
b.) Swap disk space proportional to the system’s physical memory as follows:

 

RAM Swap Space
Between 1 GB and 2 GB 1.5 times the size of RAM
Between 2 GB and 16 GB Equal to the size of RAM
More than 16 GB 16 GB

 

NOTE: The above recommendations (from the 11.2 Database installation guide) are MINIMUM recommendations for installations. Further RAM and swap space may be required to tune/improve RDBMS performance.

c.) 1.0 GB (1024MB) of disk space (and less than 2TB of disk space) in the /tmp directory.
d.) approximately 4.4 GB of local disk space for the database software.
e.) approximately 1.7 GB of disk space for a preconfigured database that uses file system storage (optional).

2. Refer Note:236826.1 for details on certified filesystems for Oracle Database.

II. Software:
============
1. As is specified in section 1.3.2 of the Oracle Database Installation Guide for 11gR2 on Linux (part number E24321-02), Oracle recommends that you install the Linux operating system with the default software packages (RPMs) and do not customize the RPMs during installation. For additional information on “default-RPMs”, please see Note 376183.1, “Defining a “default RPMs” installation of the RHEL OS” or Note 401167.1, “Defining a “default RPMs” installation of the Oracle Enterprise Linux (OEL) OS”.

2.Linux Kernel Requirements

Oracle Linux 7.0 

  • Oracle Linux 7 with Unbreakable Enterprise Kernel : 3.8.13-33.el7uek.x86_64 or later
  • Oracle Linux 7 with the Red Hat Compatible kernel : 3.10.0-54.0.1.el7.x86_64 or later

Red Hat Enterprise Linux Server 7.0

  • Red Hat Enterprise Linux 7 : 3.10.0-54.0.1.el7.x86_64 or later

NOTE:

  • RHEL7 servers must be running Red Hat kernel 3.10.0-54.0.1.el7 (x86_64) or higher or 3.8.13-33.el7uek (x86_64) or higher with UEK kernel. OL7 servers must also be running kernel 3.8.13-33.el7uek (x86_64) or higher version. The product RHEL does not deliver UEK Kernel. Only in OL 7 UEK and RHCK Kernel is included.
  • It is observed there are hang issues in RHEL 7 with many CPU cores and more RAM, due NUMA was enabled. As a work around it is recommended to turn off NUMA.

3. Required OS Components (per Release Notes, and Install Guide)

a.) The exact version number details of this list are based upon 64-bit (x86_64) RHEL 7.0. When a higher “update” level is used, the RPM release numbers (such as 4.4.4-13) may be slightly different. Since updates of RHEL 7 are certified, this is fine so long as you are still using 64-bit Linux (x86_64) RHEL 7 RPMs.
b.) Some of the Install Guide requirements will already be present from the “default-RPMs” foundation of Linux that you started with:

 

compat-libstdc++-33-3.2.3
binutils-2.23.52.0.1-12.el7.x86_64
compat-libcap1-1.10-3.el7.x86_64
gcc-4.8.2-3.el7.x86_64
gcc-c++-4.8.2-3.el7.x86_64
glibc-2.17-36.el7.x86_64
glibc-devel-2.17-36.el7.x86_64
ksh
libaio-0.3.109-9.el7.x86_64
libaio-devel-0.3.109-9.el7.x86_64
libgcc-4.8.2-3.el7.x86_64
libstdc++-4.8.2-3.el7.x86_64
libstdc++-devel-4.8.2-3.el7.x86_64
libXi-1.7.2-1.el7.x86_64
libXtst-1.2.2-1.el7.x86_64
make-3.82-19.el7.x86_64
sysstat-10.1.5-1.el7.x86_64

4. Additional Required OS Components (per the runInstaller OUI)
a.) intentionally blank

5. Additional Required OS Components (per this NOTE)
a.) Please do not rush, skip, or minimize this critical step. This list is based upon a “default-RPMs” installation of 64-bit (x86_64) RHEL 6. Additional RPMs (beyond anything known to Oracle) may be needed if a “less-than-default-RPMs” installation of 64-bit (x86_64) RHEL Server 6 is performed. For more information, please refer to Note 376183.1, “Defining a “default RPMs” installation of the RHEL OS” or Note 401167.1, “Defining a “default RPMs” installation of the Oracle Enterprise Linux (OEL) OS”.
b.) Several RPMs will be required as prerequisites to those listed in section II.3.c:  

cpp-4.8.2-16.el7.x86_64
glibc-headers-2.17-55.el7.x86_64
mpfr-3.1.1-4.el7.x86_64

 6. Oracle Global Customer Support has noticed a recent trend with install problems that originates from installing too many RPMs. For example:
a.) installing your own JDK version (prior to execute the Oracle Software runInstaller) is not needed on Linux, and is not recommended on Linux. A pre-existing JDK often interferes with the correct JDK that the Linux Oracle Software runInstaller will place and use.
b.) installing more than the required version of the gcc / g++ RPMs often leads to accidentally using (aka enabling or activating) the incorrect one. If you have multiple RDBMS versions installed on the same Linux machine, then you will likely have to manage multiple versions of gcc /g++ . For more information, please see Note 444084.1, “Multiple gcc / g++ Versions in Linux”

7. All of the RPMs in section II. are on the Red Hat Enterprise Linux 7 64-bit (x86_64) distribution media.

III. Environment:
================
1. Modify your kernel settings in /etc/sysctl.conf (RedHat) as follows. If the current value for any parameter is higher than the value listed in this table, do not change the value of that parameter. Range values (such as net.ipv4.ip_local_port_range) must match exactly. 

kernel.shmall = physical RAM size / pagesize For most systems, this will be the value 2097152. See Note 301830.1 for more information.
kernel.shmmax = 1/2 of physical RAM. This would be the value 2147483648 for a system with 4GB of physical RAM. See Note:567506.1 for more information.
kernel.shmmni = 4096
kernel.sem = 250 32000 100 128
fs.file-max = 512 x processes (for example 6815744 for 13312 processes)
fs.aio-max-nr = 1048576
net.ipv4.ip_local_port_range = 9000 65500
net.core.rmem_default = 262144
net.core.rmem_max = 4194304
net.core.wmem_default = 262144
net.core.wmem_max = 1048576

2. To activate these new settings into the running kernel space, run the “sysctl -p” command as root.

3. Set Shell Limits for the oracle User. Assuming that the “oracle” Unix user will perform the installation, do the following:

a.) Add the following settings to /etc/security/limits.conf

oracle soft nproc 2047
oracle hard nproc 16384
oracle soft nofile 1024
oracle hard nofile 65536
oracle soft stack 10240

b.) Verify the latest version of PAM is loaded, then add or edit the following line in the /etc/pam.d/login file, if it does not already exist: 

session required pam_limits.so

c.) Verify the current ulimits, and raise if needed.  This can be done many ways…adding the following lines to /etc/profile is the recommended method: 

if [ $USER = “oracle” ]; then
if [ $SHELL = “/bin/ksh” ]; then
ulimit -u 16384
ulimit -n 65536
else
ulimit -u 16384 -n 65536
fi
fi

 

4. The gcc-4.4.4 and gcc-c++-4.4.4 RPM items above will ensure that the correct gcc / g++ versions are installed. It is also required that you ensure that these correct gcc / g++ versions are active, and in-use. Ensure that the commands “gcc –version” and “g++ –version” each return “4.8.2”.

 

5. If any Java packages are installed on the system, unset the Java environment variables, for example JAVA_HOME.

6. The oracle account that is used to install Oracle 11.2.0.4 should not have the Oracle install related variables set by default. For example setting ORACLE_HOME, PATH, LD_LIBRARY_PATH to include Oracle binaries in .profile, .login file and /etc/profile.d should be completely avoided.
a.) Setting $ORACLE_BASE (not $ORACLE_HOME) is recommended, since it eases a few prompts in the OUI runInstaller tool.
b.) Following the successful install, it is recommended to set $ORACLE_HOME, and to set $PATH to include $ORACLE_HOME/bin at the beginning of the $PATH string.

7. By default, RHEL 7 x86_64 Linux is installed with SELinux as “enforcing”. This is fine for the 11gR2 installation process. However, to subsequently run “sqlplus”, switch SELinux to the “Permissive” mode. See NOTE 454196.1, “./sqlplus: error on libnnz11.so: cannot restore segment prot after reloc” for more details.

UPDATE: Internal testing suggests that there is no problem running “sqlplus” with SELinux in “enforcing” mode on RHEL7/OL7. The problem only affects RHEL5/OL5.

8. Log in as Oracle user and start the installation as follows: 

$ ./runInstaller -ignorePrereq

a.) It is best practice not to use any form of “su” to start the runInstaller, in order to avoid potential display-related problems.
b.) When performing the 11.2.0.4 installation, make sure to use the “runInstaller” version that comes with 11.2.0.4 software.
c.) When performing any subsequent 11.2.0.x patchset, make sure to use the “runInstaller” version that comes with the patchset.

Known Issue :

01) The installer needs to be launched with “-ignorePrereq” option due to unpublished bug 19947777. This issue occurs since Oracle Linux 7 was not released when Oracle database 11.2.0.4 was made available and hence was not certified. However, Oracle 11.2.0.4 is now certified on OL7. Refer Note 1962046.1 for details.

02) Compilation fails for target ‘relink_exe’ fails with “undefined reference to symbol ‘B_DestroyKeyObject’” error and is reported in unpublished bug 19692824. The solution is to install patch 19692824 as documented in Note 1965691.1.

ADDITIONAL NOTES
—————-
1. Supported distributions of the 32-bit (x86) Linux OS can run on on AMD64/EM64T and Intel Processor Chips that adhere to the x86_64 architecture
a.) Oracle 32-bit Database Server running on AMD64/EM64T with 32-bit OS is supported, but is NOT covered by this NOTE.
b.) Oracle 32-bit Database Server running on AMD64/EM64T with 64-bit OS is not certified and is not supported.
c.) Oracle 32-bit Database Client running on AMD64/EM64T with 64-bit OS is expected to be supported, but is NOT covered by this NOTE.

2. Asynchronous I/O on ext2 and ext3 file systems is supported if your scsi/fc driver supports that functionality. 

Note : Asynchronous I/O on Ext4 file system is supported with Oracle 10g onwards on OEL5.6 and later.
Reference : Oracle Linux, Filesystem & I/O Type Supportability (Note 279069.1)

3. No extra patch is required for the DIRECTIO support for x86_64.

4. No LD_ASSUME_KERNEL value should be used with the 11gR2 product.

5. The following rpm command can be used to distinguish between a 32-bit or 64-bit package.   

# rpm -qa –queryformat “%{NAME}-%{VERSION}-%{RELEASE} (%{ARCH})\n” | grep glibc-devel
glibc-devel-2.12-1.7(x86_64)
glibc-devel-2.12-1.7(i686)
Installation walk-through – Oracle Grid/RAC 11.2.0.4 on Oracle Linux 7 (Doc ID 1951613.1)

APPLIES TO:
Oracle Database – Enterprise Edition – Version 11.2.0.4 to 11.2.0.4 [Release 11.2]
Oracle Database Cloud Schema Service – Version N/A and later
Oracle Database Exadata Cloud Machine – Version N/A and later
Oracle Cloud Infrastructure – Database Service – Version N/A and later
Oracle Database Backup Service – Version N/A and later
Linux x86-64

PURPOSE

This document aims to provide clarity on the installation/patching processes required while installing Oracle Grid 11.2.0.4.0 and Oracle RAC 11.2.0.4.0 on Oracle Linux 7 by providing details on the steps taken to complete an example installation. For general recommendations, refer to Note 1962100.1 “Requirements for Installing Oracle 11.2.0.4 RDBMS on OL7 or RHEL7 64-bit (x86-64)”

SCOPE
This document is intended to complement the official Oracle documentation. If there are any incompatibilities between this document and the official Oracle documentation, they are unintentional, and should be ignored. This document is not meant to be a substitute for official documentation; care should be taken to ensure that all official documentation is reviewed thoroughly.

DETAILS
Operating System Installation & Setup – Recommendations

Yum Repository
Set up public-yum repository and enable the latest AddOns channels, e.g.

# cat /etc/yum.repos.d/public-yum-ol7.repo
[ol7_latest]
name=Oracle Linux $releasever Latest ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL7/latest/$basearch/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
gpgcheck=1
enabled=1

[ol7_addons]
name=Oracle Linux $releasever Add ons ($basearch)
baseurl=http://public-yum.oracle.com/repo/OracleLinux/OL7/addons/$basearch/
gpgkey=file:///etc/pki/rpm-gpg/RPM-GPG-KEY-oracle
gpgcheck=1
enabled=1

 

11gR2 preinstall RPM
Install 11gR2 preinstall rpm. The preinstall rpm installs all dependencies for the Oracle RDBMS server installation, and creates the oracle user and the dba and oinstall groups.

Oracle ASMLib
Download the certified oracleasmlib package from OTN (http://www.oracle.com/technetwork/server-storage/linux/asmlib/ol7-2352094.html)

Install oracleasm packages if oracleasmlib is to be used

 

yum install oracleasm-support.x86_64 oracleasmlib-2.0.8-2.el7.x86_64.rpm

 

Oracle Automatic Storage Management Cluster File System (Oracle ACFS)
For details on ACFS support, including required patches, refer to Note 1369107.1 (ACFS Support On OS Platforms (Certification Matrix)

Disk Naming Consistency
For consistent disk naming, install device-mapper-multipath along with associated dependencies (device-mapper-multipath-libs.x86_64)

 

yum install device-mapper-multipath

 

Multipathing

Start multipathd, and verify status e.g.

 

[root@xxxx ~]# systemctl start multipathd
[root@xxxx ~]# systemctl status multipathd


SELinux
Disable, e.g.

setenforce 0

Oracle Grid Infrastructure – Installation Notes
Patch 19404309

Note: It is presumed that the user has already reviewed the Oracle Grid Infrastructure Installation Guide and associated Release Notes; instructions and/or recommendations from those documents will not be repeated here.

After downloading the Oracle Grid Infrastructure software, and before attempting any installation, download Patch 19404309 from My Oracle Support, and apply the patch using the instructions in the patch README.

Patch 18370031

Download Patch 18370031 from My Oracle Support. Then, start an interactive Oracle Grid Infrastructure installation through the Oracle Universal Installer (OUI), but do not execute root.sh on any node until afterthe application of Patch 18370031. When the OUI prompts the user to execute the root.sh scripts*, Patch 18370031 should be applied by following the instructions in Section 2.3, Case 5 – Patching a Software Only GI Home Installation or Before the GI Home Is Configured – of the patch README. Note: The README should be reviewed in full, as it contains other requirements (e.g. upgrading OPatch, etc.).

* If executing a software-only installation, the patch should be applied after the installation concludes, but before any configuration is attempted.

Once Patch 18370031 has been applied, proceed with the remainder of the installation (or configuration).

Oracle Database/RAC – Installation Notes
Note: As the title suggests, this section applies both to installations of Oracle Database and Oracle Real Application Clusters (RAC).

Patch 19404309
Note: It is presumed that the user has already reviewed the Oracle Database, Oracle RAC Installation Guides and associated Release Notes; instructions and/or recommendations from those documents will not be repeated here.

After downloading the Oracle Database/RAC software, and before attempting any installation, download Patch 19404309 from My Oracle Support, and apply the patch using the instructions in the patch README.

Patch 19692824
During installation of Oracle Database or Oracle RAC on OL7, the following linking error may be encountered:

 

Error in invoking target ‘agent nmhs’ of makefile ‘<ORACLE_HOME>/sysman/lib/ins_emagent.mk’. See ‘<installation log>’ for details.
If this error is encountered, the user should select Continue. Then, after the installation has completed, the user must download Patch 19692824 from My Oracle Support and apply it per the instructions included in the patch README.

Installation/Home Cloning
Note: It may be possible to perform the above steps once, then use Oracle’s cloning technology to clone the installation/home. Further details are available in the cloning sections of the relevant Administration and Deployment guides:

Cloning Oracle Clusterware

Cloning Oracle RAC to Nodes in a New Cluster

Cloning Oracle Software

Devos加密病毒的oracle数据库恢复

某用户的oracle数据库因devos后缀加密病毒devos ransomware malware ,数据文件被全部加密:

 

该加密病毒的后缀为 SYSTEM01.DBF.id[2245DCEC-2700].[geerban@email.tg].Devos, 针对该病毒可以基于prm-dul恢复工具来恢复其中的数据,演示视频可以参考:

https://zcdn.parnassusdata.com/prm%20dul%20recover%20malware%20ransomware%20corrupted%20oracle%20datafile.mp4

 

PRM-DUL 绿色版自带JAVA运行环境

PRM-DUL 绿色版自带JAVA运行环境

https://zcdn.parnassusdata.com/DUL5108rc8_java.zip

 

Oracle中的SYS_NC00$ SYS_C000$ SYS_STU SYS_STS 和虚拟字段

SYS_NC00是一种系统自动生成的辅助列,在Oracle 12c以后大量出现在用户表中,其主要伴随一下这些功能出现:

 

  • row archival;
  • create index t_i on t(upper(v)); 函数索引
  • alter table xxx add (b integer default 1);  default 值

 

property:

0x0008 = virtual column(old)

0x0020 = hidden column(old)

0x00010000 = expression column(new)

default$: is overloaded to store index expression

name: is system generated. It is SYS_NC<5 digit intcol#>$

 

SYS_C000$ 伴随以下功能出现:

 

各种未指定名字的约束

 

CONSTRAINT constraint_name
Specify a name for the constraint. If you omit this identifier, then Oracle Database generates a name with the form SYS_Cn. Oracle stores the name and the definition of the integrity constraint in the USER_, ALL_, and DBA_CONSTRAINTS data dictionary views (in the CONSTRAINT_NAME and SEARCH_CONDITION columns, respectively).

 

The references_clause of the ref_constraint syntax lets you define a foreign key constraint on the REF column. This clause also implicitly restricts the scope of the REF column or attribute to the referenced table. However, whereas a foreign key constraint on a non-REF column references an actual column in the parent table, a foreign key constraint on a REF column references the implicit object identifier column of the parent table.

If you do not specify a constraint name, then Oracle generates a system name for the constraint of the form SYS_Cn.

https://docs.oracle.com/cd/B19306_01/server.102/b14200/clauses002.htm#sthref2891

 

 

SYS_STU  SYS_STS伴随多列统计信息出现 ; 其中STU代表用户创建的多列统计信息, STS是SYS_STS are system generated from the DECODE in ALL_STAT_EXTENSIONS

 

Create column groups for the customers_test table based on the usage information captured during the monitoring window.

For example, run the following query:

SELECT DBMS_STATS.CREATE_EXTENDED_STATS(user, ‘customers_test’) FROM DUAL;
Sample output appears below:

###########################################################################
EXTENSIONS FOR SH.CUSTOMERS_TEST
…………………………..
1. (CUST_CITY, CUST_STATE_PROVINCE,
COUNTRY_ID) :SYS_STUMZ$C3AIHLPBROI#SKA58H_N created
2. (CUST_STATE_PROVINCE, COUNTRY_ID):SYS_STU#S#WF25Z#QAHIHE#MOFFMM_ created
###########################################################################
The database created two column groups for customers_test: one column group for the filter predicate and one group for the GROUP BY operation.

 

用户所自行创建的虚拟列 其SYS.COL$ 的property一般等于65544

flutter Slide拖动滑条


main.dart 

import 'package:flutter/material.dart';

void main() => runApp(MyApp());

class MyApp extends StatelessWidget {
  @override
  Widget build(BuildContext context) {
    return MaterialApp(
        debugShowCheckedModeBanner: false,
        title: 'This is a Slide Example',
        home: Scaffold(
            appBar: AppBar(
              title: Text('ABC'),
            ),
            body: Column(children: [
              Padding(
                child: Text(
                  'This is a Slide Example',
                  style: TextStyle(fontSize: 20),
                ),
                padding: EdgeInsets.all(50),
              ),
              SlideExample(),
              RangeSliderExample()
            ])));
  }
}

class SlideExample extends StatefulWidget {
  @override
  _Slider1State createState() => _Slider1State();
}

class _Slider1State extends State {
  double rating = 0;
  @override
  Widget build(BuildContext context) {
    // TODO: implement build

    return Slider(
      label: "$rating",
      divisions: 10,
      value: rating,
      onChanged: (newRating) {
        setState(() => rating = newRating);
      },
    );
  }
}

class RangeSliderExample extends StatefulWidget {
  @override
  _RangeSliderExampleState createState() => _RangeSliderExampleState();
}

class _RangeSliderExampleState extends State {
  var selectedRange = RangeValues(0.2, 0.8);

  @override
  Widget build(BuildContext context) {
    // TODO: implement build
    return RangeSlider(
      values: selectedRange,
      onChanged: (RangeValues newRange) {
        setState(() {
          selectedRange = newRange;
        });
      },
    );
  }
}


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