【蘇州IT外包經驗】ping不通的情況下，如何掃描端口

Ping不通對方的主機能掃描到他的端口嗎？答案是肯定的

1、現象：某個IP被網關禁ping了，但想知道它開了哪些端口

2、準備工具：nmap

3、命令格式：nmap X.X.X.X -Pn1-65535

??????? 1-65535是指定端口范圍

4、測試結果如圖

使用“alter system register;”解決動態監聽注冊緩慢問題

感受一下Oracle數據庫實例的動態監聽注冊細節。有如下這樣一個規律，先總結在這里：
①如果是先啟動監聽，后啟動數據庫實例，則動態監聽會自動識別到啟動的數據庫實例；
②在數據庫實例正常運行的情況下重啟監聽，則數據庫實例會等很長時間才能在動態監聽中注冊成功，大約需要1分鐘的等待時間；
③如果是先啟動數據庫實例，后啟動監聽，效果和②一樣；
④如果不希望長時間等待動態監聽注冊的過程，可以使用“alter system register;”命令加速。

真實的體驗一下這個過程。切身體驗之后這些結論將顯得那樣的自然和純真。

1.第①種場景模擬
1）在數據庫實例未啟動時啟動監聽程序
ora11g@secdb /home/oracle$ sqlplus / as sysdba

SQL*Plus: Release 11.2.0.1.0 Production on Tue Jan 18 20:47:22 2011

Copyright (c) 1982, 2009, Oracle.? All rights reserved.

Connected to an idle instance.

NotConnected@> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:48:58

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 29-DEC-2010 02:03:55
Uptime??????????????????? 20 days 18 hr. 45 min. 3 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

因為數據庫實例沒有啟動，監聽理所當然地處于未檢測到任何實例的狀態。

2）啟動數據庫實例
NotConnected@> startup;
ORACLE instance started.

Total System Global Area? 535662592 bytes
Fixed Size????????????????? 1337720 bytes
Variable Size???????????? 411043464 bytes
Database Buffers????????? 117440512 bytes
Redo Buffers??????????????? 5840896 bytes
Database mounted.
Database opened.

3）隨即查看監聽狀態
sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:49:15

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 29-DEC-2010 02:03:55
Uptime??????????????????? 20 days 18 hr. 45 min. 20 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
? Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully

第①種場景結論得到印證：
①如果是先啟動監聽，后啟動數據庫實例，則動態監聽會自動識別到啟動的數據庫實例；

2.第②種場景模擬
1）手工停啟監聽程序
sys@ora11g> !lsnrctl stop

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:52:55

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
The command completed successfully

sys@ora11g> !lsnrctl start

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:03

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Starting /oracle/ora11gR2/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.1.0 - Production
System parameter file is /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 0 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

2）每隔一秒檢查一下監聽的狀態
sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:11

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 7 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

……省略部分狀態檢查信息……

sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:14

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 11 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

……省略部分狀態檢查信息……

sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:22

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 18 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

……省略部分狀態檢查信息……

sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:58

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 55 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

可見，直到20:53:58時數據庫實例仍然沒有注冊到監聽中，此時距離啟動監聽的時候20:53:03已經過去55秒。

最后是在20:53:59成功完成注冊。
sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 20:53:59

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 20:53:03
Uptime??????????????????? 0 days 0 hr. 0 min. 56 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
? Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully

距離啟動監聽時間56秒，大約用了1分鐘的時間才完成數據庫實例到監聽的動態注冊。

第②種場景結論得到印證：
②如果是先啟動數據庫實例，后啟動監聽，則數據庫實例會等很長時間才能在動態監聽中注冊成功，大約需要1分鐘的等待時間；

3.第③種場景和第②種場景式樣的，不贅述。

4.第④種場景模擬
模擬這個場景比較簡單，只需要連續執行如下這幾條命令即可。
!lsnrctl stop
!lsnrctl start
!lsnrctl status
alter system register;
!lsnrctl status

以下是連續執行后的結果。

1）停止監聽程序
sys@ora11g> !lsnrctl stop

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:40

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
The command completed successfully

2）啟動監聽程序
sys@ora11g> !lsnrctl start

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Starting /oracle/ora11gR2/product/11.2.0/dbhome_1/bin/tnslsnr: please wait...

TNSLSNR for Linux: Version 11.2.0.1.0 - Production
System parameter file is /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Log messages written to /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
Listening on: (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 21:30:44
Uptime??????????????????? 0 days 0 hr. 0 min. 0 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

3）查看監聽狀態
sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 21:30:44
Uptime??????????????????? 0 days 0 hr. 0 min. 0 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
The listener supports no services
The command completed successfully

此時，監聽未檢測到數據庫實例信息。

4）手工強制將數據庫實例注冊到監聽
sys@ora11g> alter system register;

System altered.

5）最后確認監聽狀態
sys@ora11g> !lsnrctl status

LSNRCTL for Linux: Version 11.2.0.1.0 - Production on 18-JAN-2011 21:30:44

Copyright (c) 1991, 2009, Oracle.? All rights reserved.

Connecting to (DESCRIPTION=(ADDRESS=(PROTOCOL=IPC)(KEY=EXTPROC1521)))
STATUS of the LISTENER
------------------------
Alias???????????????????? LISTENER
Version?????????????????? TNSLSNR for Linux: Version 11.2.0.1.0 - Production
Start Date??????????????? 18-JAN-2011 21:30:44
Uptime??????????????????? 0 days 0 hr. 0 min. 0 sec
Trace Level?????????????? off
Security????????????????? ON: Local OS Authentication
SNMP????????????????????? OFF
Listener Parameter File?? /oracle/ora11gR2/product/11.2.0/dbhome_1/network/admin/listener.ora
Listener Log File???????? /oracle/ora11gR2/diag/tnslsnr/secdb/listener/alert/log.xml
Listening Endpoints Summary...
? (DESCRIPTION=(ADDRESS=(PROTOCOL=ipc)(KEY=EXTPROC1521)))
? (DESCRIPTION=(ADDRESS=(PROTOCOL=tcp)(HOST=secdb)(PORT=1521)))
Services Summary...
Service "ora11g" has 1 instance(s).
? Instance "ora11g", status READY, has 1 handler(s) for this service...
The command completed successfully

通過手工注冊數據庫實例的方法，立桿見影，實例旋即注冊到了監聽程序中。

第④種場景結論得到印證：
④如果不希望長時間等待動態監聽注冊的過程，可以使用“alter system register;”命令加速。

5.小結
如果您能將這個過程“躬親”一下，也許會有這種很美妙的感覺：一切都是那樣的自然而和諧。

再次將有關動態監聽的結論附在這里：
①如果是先啟動監聽，后啟動數據庫實例，則動態監聽會自動識別到啟動的數據庫實例；
②在數據庫實例正常運行的情況下重啟監聽，則實例會等很長時間才能在動態監聽中注冊成功，大約需要1分鐘的等待時間；
③如果是先啟動數據庫實例，后啟動監聽，效果和②一樣；
④如果不希望長時間等待動態監聽注冊的過程，可以使用“alter system register;”命令加速。

【蘇州IT外包經驗】Ubuntu 17.10系統下配置PHP+Apache+Mysql

本文為Ubuntu 17.10系統下配置PHP7.1+Apache2.4+Mysql5.7

一、Apache2

??? 安裝apache

??? sudo apt-get apache2

?
??? 編輯apache主配置文件/etc/apache2/apache2.conf，修改KeepAlive設置

??? KeepAlive Off

???? Apache默認的multi-processing模塊(MPM ) 是一個event 模塊，但是 php默認是使用 prefork模塊，禁用event模塊，啟用prefork模塊

??? sudo a2dismod mpm_event
??? sudo a2enmod mpm_prefork

??? 重啟Apache

??? sudo service apache2 restart


??? 如果在重啟Apache時，看見關于ServerName的報錯，可以做如下修改
??????? 編輯apache主配置文件/etc/apache2/apache2.conf
??????? 添加一行ServerName localhost
??????? 然后執行sudo service apache2 restart

二、Mysql5.7

??? sudo apt-get install mysql-server mysql-client
??? # 在安裝過程中要輸入root的密碼

??? 安裝完成后，執行mysql_secure_installation，根據提示完成安全設置

三、PHP7.0

??? sudo apt-get install php7.0

四、LAMP

??? 整合PHP和MySQL
?? ?
??? sudo apt-get install php-gd php-mysql

??? 整合PHP和Apache

??? sudo apt-get install libapache2-mod-php7.0
??? sudo service apache2 restart


五、驗證環境

??? 顯示PHP的版本信息

??? php -v

??? Apache默認的網站根目錄位于/var/www/html/,進入這個目錄，并創建info.php

??? sudo nano /var/www/html info.php

??????? <?php
??????????? phpinfo();
??????? ?>

?在瀏覽器中輸入http://localhost/info.php進行驗證

【蘇州IT外包經驗】VMware Workstation pro 14 for Linux not usable with all the kernel 4.13-rc's

Ubuntu升級到17.10后，VMware workstation不能打開虛擬機，提示“The virtual machine is unable to reserve memory. If selecting Retry does not work, try powering off or suspending any other virtual machines first”

一、環境：

物理機：Ubuntu 17.10+VMware workstation Pro 14或12.5

虛擬機：Windows 10、Windows 7、macOS 12

二、解決方法如下 ：

1、進入你的個人文件夾或你有修改權限的文件夾

cd ~

2、備份原vmmon.tar文件，膽子大的可忽略此步
cp /usr/lib/vmware/modules/source/vmmon.tar .?????????????????? //最后有個點，別忘了

3、提取壓縮包
tar xf vmmon.tar

4、下載新的vmmon包

VMware workstation pro 14下載地址：

wget?-O?./vmmon-only/linux/hostif.c?https://raw.githubusercontent.com/mkubecek/vmware-host-modules/fadedd9c8a4dd23f74da2b448572df95666dfe12/vmmon-only/linux/hostif.c

本地下載

VMware workstation pro 12.5下載地址：

wget?-O?./vmmon-only/linux/hostif.c?https://raw.githubusercontent.com/mkubecek/vmware-host-modules/b50848c985f1a6c0a341187346d77f0119d0a835/vmmon-only/linux/hostif.c

本地下載

5、將新修改的文件包裝成一個壓縮包替換原始文件
sudo tar cf /usr/lib/vmware/modules/source/vmmon.tar vmmon-only

6、重新編譯vmware內核模塊
sudo vmware-modconfig --console --install-all

7、重啟物理機
sudo reboot