There are a few essential tricks and tools that should be included in every Active Directory disaster-recovery plan. Tombstone reanimation is one of these techniques, offering the only way to recover deleted objects without taking a domain controller off line. Here’s a guide to finding and recovering tombstones in Active Directory.
In a large organization, even the most common Active Directory tasks, such as adding and modifying objects, can be tedious and time-consuming. These 11 tools can make Active Directory management a lot easier.
There are a few essential tricks and tools that should be included in every Active Directory disaster-recovery plan. Tombstone reanimation is one of these techniques, offering the only way to recover deleted objects without taking a domain controller off line. Here’s a guide to finding and recovering tombstones in Active Directory.
In a large organization, even the most common Active Directory tasks, such as adding and modifying objects, can be tedious and time-consuming. These 11 tools can make Active Directory management a lot easier.
Keyword stuffing is one of the oldest spamming techniques on the Internet. Many webmasters still use that technique although most search engines can detect it nowadays. Last week, Google’s anti-spam engineer Matt Cutts made fun of a website that used keyword stuffing.
Discover how to import and export SharePoint list items using SQL Server Integration Services and the new Collaborative Application Markup Language (CAML).
MySQL K.K., the Japanese subsidiary of MySQL AB today announced free pre-registration for the MySQL Users Conference Japan 2007, the first MySQL users conference to be held in Asia.
Date: Tuesday, September 11 & Wednesday, September 12, 2007
Location: National Museum of Emerging Science and Innovation
Admission fee: Free, if pre-registered. Participation on that day is 5,000 yen.
Pre-registration: www.mysql-ucj2007.jp/english
Main sponsor: MySQL AB
MySQL AB today announced that BlueLithium, a leading online marketing company, is implementing a business-critical data warehouse application built upon MySQL and the BrightHouse database engine from Infobright Inc. MySQL AB and Infobright, a MySQL Certified Storage Engine partner, are expanding their relationship to jointly offer customers analytic data warehousing solutions.
Working on large upgrade of MySQL 4.1 running Innodb to MySQL 5.0 and doing oprofile analyzes we found very interesting issue of buf_get_latched_pages_number being responsible for most CPU usage. It did not look right.
The close look revealed this is the function which is used to compute number of latched pages in Innodb Buffer Pool, which is called when you run SHOW INNODB STATUS and SHOW STATUS. In this case for same of monitoring SHOW GLOBAL STATUS was run every couple of seconds being considered fast operation, as it is in MySQL 4.1
But why buf_get_latched_pages_number ? Because this function traverses whole buffer pool to compute number of latched pages, which is quite slow with buffer pools containing millions of pages. But even worse this is done while holding global buffer pool mutex.
Another function which we’ve seen being responsible for high CPU usage is ha_print_info which also may traverse large arrays.
But this is only one of the gotchas. The second issue we ran into is number of Threads_Running being much higher for MySQL 5.0 compared to MySQL 4.1 It was something like 2-3 for MySQL 4.1 vs 40-60 for MySQL 5.0
At the same time however there were virtually no disk IO and CPU being loaded less than 20% (out of 4 Cores) in all cases which points to some locks/latches being responsible for this high amount of threads.
It turns out this issue is side effect of the first issue described - if many queries are being run and buffer pool is large, a lot of queries pile up waiting on locked innodb buffer pool mutex, so SHOW STATUS shows high number of running threads.
This theory can be confirmed by the fact using mysqladmin processlist | grep -v Sleep shows much smaller value which is close in MySQL 5.0 and 4.1
Hopefully this issue will be fixed sooner or later (I would be even happy to give up Innodb_buffer_pool_pages_latched n SHOW STATUS output
It is true you might be better of being unaware about problems, because in this case you might not run into them 
Just couple of days ago Kaj Arno told me there are issues reported with SHOW PROFILE patch available in latest MySQL Community Edition and I’ve been troubleshooting customer affected by one of these very issues today.
The Bug can dramatically increase System CPU usage (about 10 times in this case)
The “fix” was to get MySQL 5.0.44 sources from Dorsal Source which base
