MySQL: Moving Database from Windows to Linux I have a Windows based dedicated server have below configuration:

Windows edition: Windows Server 2008 R2 Standard Service Pack 1
Processor: Intel(R) Xeon(R) CPU X5460 @3.16GHZ 3.16 GHZ (2 Processors)
Installed Memory(RAM): 8.00 GB
System type: 64-Bit Operating system


Even, I am facing bad performance of my application. DB connections become high >100 and system starts running slower. It become dead when DB connection reached to around 200. While we defined MAX connection=800. I already tried multiple things like - 
MySQL configuration variables tuning 
Identified and improved the bad performing queries

Above steps helped a little bit but still facing very bad performance. It is just like I am swimming in the ocean without any expertise and life saving boat.

Now, I am planning to upgrade MySQL from 5.1 to 5.6 as well as switching from Windows to Linux. I guess as Open source - Linux  must have multiple tools to measure performance and tuning tools for Windows. But, before this I want to be sure about below things:


How much will it be useful in performance improvement? 
My application is running in dedicated Windows server. Switching application servers also required? 
Need to tune MySQL configuration variables again? 
What should be the configuration (hardware and software) of LINUX based system?
What performance measurement and tuning tools are available for LINUX?


Many Thanks :)
You can try Percona wizard tool to configure MySQL server parameter based on Hardware and application in use using https://tools.percona.com/wizard
also there are other online tools available at https://cloud.percona.com/ all percona tools are free.

Some similar answsers to the questions can be found here:
https://stackoverflow.com/questions/11574401/mysql-monitor-queries

https://stackoverflow.com/questions/12026488/mysql-query-monitor-tool