实在是受不了GFW，利用AppEngine帐号setup了一个GAppProxy。
很简单。再配合AutoProxy，可以自由访问blogger，facebook了。
唯一的困难是https还有问题，不能正常使用twitter。
有人已经有些思路。期待能够解决
Monday, July 13, 2009
Sunday, April 19, 2009
two bad things for database server on linux
Today saw a post about swappiness in pythian. It recalls my memory of tuning oracle on linux.
Linux is great, but not all things on linux are optimal for database. There are two bad things. One is swappiness, another one is file cache. If you run oracle on linux default, you may find the file system cache often grabs huge memory and system is busy in paging out oracle processes. It's too bad.
The solution is 1) setting swappiness to zero, it tells linux to release file cache instead of swapping processes to disk when memory is tight 2) use DIRECT_IO (no file system caching in db2), it bypass file cache so not suffers double-buffering.
Linux is great, but not all things on linux are optimal for database. There are two bad things. One is swappiness, another one is file cache. If you run oracle on linux default, you may find the file system cache often grabs huge memory and system is busy in paging out oracle processes. It's too bad.
The solution is 1) setting swappiness to zero, it tells linux to release file cache instead of swapping processes to disk when memory is tight 2) use DIRECT_IO (no file system caching in db2), it bypass file cache so not suffers double-buffering.
Thursday, November 06, 2008
32位系统上如何让Oracle数据库使用超过2G内存
今天一个朋友问到这个问题，记录一下。
32位系统都有个地址空间的问题，它限制了可以使用的Oracle SGA大小。
32位Windows有两个boot设置:/3G允许进程使用3GB的用户地址空间;/PAE允许进程使用超过4GB的内存。
修改boot.ini如下，然后重启系统。
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /fastdetect /3G /PAE
如果启用/3G，可以设置Oracle SGA大小到接近3GB；如果启用/PAE，再设置use_indirect_data_buffer=TRUE和db_block_buffers，data buffer大小不受4GB限制，可以很大。
而32位Linux下增大SGA limits需要relink；设置ramfs和use_indirect_data_buffer可以支持很大的data buffer。
32位系统都有个地址空间的问题，它限制了可以使用的Oracle SGA大小。
32位Windows有两个boot设置:/3G允许进程使用3GB的用户地址空间;/PAE允许进程使用超过4GB的内存。
修改boot.ini如下，然后重启系统。
[boot loader]
timeout=30
default=multi(0)disk(0)rdisk(0)partition(1)\WINDOWS
[operating systems]
multi(0)disk(0)rdisk(0)partition(1)\WINDOWS="Windows Server 2003, Enterprise" /fastdetect /3G /PAE
如果启用/3G，可以设置Oracle SGA大小到接近3GB；如果启用/PAE，再设置use_indirect_data_buffer=TRUE和db_block_buffers，data buffer大小不受4GB限制，可以很大。
而32位Linux下增大SGA limits需要relink；设置ramfs和use_indirect_data_buffer可以支持很大的data buffer。
Tuesday, September 02, 2008
Get out of ORA-28002: the password will expire within n days
Today, a colleage meet this ORA-28002 when starting Content Server. It's a bit annoying.
So try to find the way to get out of this error.
This post does great to explain the problem. While even followed its solution B, the ORA-28002 remains there.
Then from Metalink note 162818.1, "ORA-28002 On User Connection Immediately After PASSWORD_LIFE_TIME Changed", it is known that "Accounts that have entered their grace
period will have to change their passwords.", even though the PASSWORD_LIFE_TIME is set back to unlimited.
Final workaround is altering user's password to the previous one. It doesn't change password, but bypass the annoying password life management.
Steps to record:
1. check out the password limits set to the user.
SQL> select LIMIT, RESOURCE_NAME from dba_profiles where RESOURCE_NAME in 'PASSWORD_GRACE_TIME','PASSWORD_LIFE_TIME','PASSWORD_REUSE_MAX','PASSWORD_REUSE_TIME') and PROFILE=(select profile from dba_users where username=);
2. check out the profile of the user.
SQL> select profile from dba_users where username=;
3. alter the profile, set the limits to unlimited.
SQL> alter profile limit PASSWORD_LIFE_TIME UNLIMITED;
SQL> alter profile limit PASSWORD_GRACE_TIME UNLIMITED;
4. if the user has entered the grace period (ORA-28002 when login), the password has to be altered. Fortunately you need not really change it.
SQL> alter user identified by ;
That's all.
So try to find the way to get out of this error.
This post does great to explain the problem. While even followed its solution B, the ORA-28002 remains there.
Then from Metalink note 162818.1, "ORA-28002 On User Connection Immediately After PASSWORD_LIFE_TIME Changed", it is known that "Accounts that have entered their grace
period will have to change their passwords.", even though the PASSWORD_LIFE_TIME is set back to unlimited.
Final workaround is altering user's password to the previous one. It doesn't change password, but bypass the annoying password life management.
Steps to record:
1. check out the password limits set to the user.
SQL> select LIMIT, RESOURCE_NAME from dba_profiles where RESOURCE_NAME in 'PASSWORD_GRACE_TIME','PASSWORD_LIFE_TIME','PASSWORD_REUSE_MAX','PASSWORD_REUSE_TIME') and PROFILE=(select profile from dba_users where username=
2. check out the profile of the user.
SQL> select profile from dba_users where username=
3. alter the profile, set the limits to unlimited.
SQL> alter profile
SQL> alter profile
4. if the user has entered the grace period (ORA-28002 when login), the password has to be altered. Fortunately you need not really change it.
SQL> alter user
That's all.
Tuesday, August 05, 2008
Virtualization is amazing
I knew VMWare before. I even tried VMWare Workstation before. I thought virtualization tech is interesting, but performance-slow and resource-inefficiency.
Until now, I found that the new company proactively utilizes various VMWare products, such as ESX Server, Virtual Center and Lab Manager. They are awasome. Tremendous installation/setup time are saved. Repeated tasks are automated. Daily works are extremely simplied. Productivity are largely promoted.
Check out this video of Lab Manager. http://download3.vmware.com/demos/labmanager/
EMC buying VMWare is a great deal. Don't let it slip way.
Until now, I found that the new company proactively utilizes various VMWare products, such as ESX Server, Virtual Center and Lab Manager. They are awasome. Tremendous installation/setup time are saved. Repeated tasks are automated. Daily works are extremely simplied. Productivity are largely promoted.
Check out this video of Lab Manager. http://download3.vmware.com/demos/labmanager/
EMC buying VMWare is a great deal. Don't let it slip way.
Thursday, January 17, 2008
Oracle to Acquire BEA Systems
Oracle to Acquire BEA Systems
"The addition of BEA products and technology will significantly enhance and extend Oracle's Fusion middleware software suite," said Oracle CEO Larry Ellison.
终于把BEA买下来了，是个好事。一直觉得OC4J不咋的，希望WebLogic以后做为Fusion middleware的核心。
"The addition of BEA products and technology will significantly enhance and extend Oracle's Fusion middleware software suite," said Oracle CEO Larry Ellison.
终于把BEA买下来了，是个好事。一直觉得OC4J不咋的，希望WebLogic以后做为Fusion middleware的核心。
Thursday, December 20, 2007
Pythian Group Blog » Blog Archive » Pythian Goodies: The Answer to Free Memory, Swap, Oracle, and Everything
Pythian Group Blog » Blog Archive » Pythian Goodies: The Answer to Free Memory, Swap, Oracle, and Everything:
"# Linux Oracle servers must use HugePages.
# Being low on free memory is not an issue.
# Using DirectIO is important to maintaining a useful file system cache."
"If the system is capable of running 64-bit Linux then it should. Using the VLM workaround adds significant overhead to database cache access."
"# Linux Oracle servers must use HugePages.
# Being low on free memory is not an issue.
# Using DirectIO is important to maintaining a useful file system cache."
"If the system is capable of running 64-bit Linux then it should. Using the VLM workaround adds significant overhead to database cache access."
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