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Search Results for: many file handle

How Percona Support handles bugs

One of the great values of a Percona Support contract is that we provide bug fixes for covered software, and not just support in terms of advice on how to use it. This is the …

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Looking deeper into InnoDB’s problem with many row versions

A few days ago I wrote about MySQL performance implications of InnoDB isolation modes and I touched briefly upon the bizarre performance regression I found with InnoDB handling a large amount of versions for a single …

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File carving methods for the MySQL DBA

This is a long overdue blog post from London’s 44con Cyber Security conference back in September. A lot of old memories were brought to the front as it were; the one I’m going to cover in …

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MySQL Error: Too many connections

We have always received quite few questions here at Percona Support on how to avoid the dreaded “Too many connections” error, as well as what is the recommended value for max_connections. So, in this article …

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Getting MySQL Core file on Linux

Core file can be quite helpful to troubleshoot MySQL Crashes yet it is not always easy to get, especially with recent Linux distributions which have security features to prevent core files to be dumped by …

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How many fsync / sec FusionIO can handle

I recently was asked how many fsync / sec ( and therefore durable transactions / sec) we can get on FusionIO card. It should be easy to test, let’s take sysbench fileio benchmark and run, …

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How to load large files safely into InnoDB with LOAD DATA INFILE

Recently I had a customer ask me about loading two huge files into InnoDB with LOAD DATA INFILE. The goal was to load this data on many servers without putting it into the binary log. …

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PHP Sessions – Files vs Database Based

One may think changing PHP session handler from file based to database driven is fully transparent. In many cases it is, sometimes however it may cause some unexpected problems as happened to one of our …

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Why do you need many apache children ?

I already wrote kind of about same topic a while ago and now interesting real life case makes me to write again Most Web applications we’re working with have single tier web architecture, meaning there …

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Is 80% of RAM how you should tune your innodb_buffer_pool_size?

It seems these days if anyone knows anything about tuning InnoDB, it’s that you MUST tune your innodb_buffer_pool_size to 80% of your physical memory. This is such prolific tuning advice, it seems engrained in many …

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