Mysql high virtual memory usage

Requested dynamically memory : Thread Buffers is used by MySQL which is the memory that’s requested from the operating system as and when a new query is processed. After the execution of the query, this memory is released back to the operating system. This means that memory usage of MySQL is Global Buffers plus the Thread Buffers along with the maximum number of allowed connections. This value should always be kept below of server memory for a dedicated database server.

Assume you have a system (physical or virtual ) with 16GB of memory. We are only running MySQL on this system, with an InnoDB storage engine and use innodb_flush_method=O_DIRECT, so we can allocate (or 1GB) of memory to MySQL. For our workloa we assume connection handling and other MySQL connection-based. MySQL has only mapped the memory pages, and is not actually using them. Linux memory usage can be very confusing sometimes.

You can see from your top output by yourself that no swap has been used , and RAM is mostly unused too. This is a development machine, and many others applications will be installed on it. A minimal amount of memory will be used by MySQL in all MySQL versions before 5. Development Machine mode.

The Microsoft Windows Virtual Memory Manager (VMM) takes pages from SQL Server and other processes as it trims the working-set sizes of those processes. This VMM activity tends to cause page faults. Now we can check things inside MySQL to look for potential MySQL memory leaks. MySQL allocates memory in tons of places.

These days, it is common to see production grade database servers with literally 100x that amount. MB of memory usage makes no significant difference to one of these servers, but definitely noticible to a 512MB virtual machine. By Nilnandan Joshi Insight for DBAs, MySQL , Percona Services MySQL server memory usage, troubleshooting tips Comments There are many blog posts already written on topics related to “ MySQL server memory usage ,” but nevertheless there are some who still get confused when troubleshooting issues associated with memory usage for MySQL. How to reduce mysql memory used. But when I installe it used too much memory , about 420Mb although 5. If you have been using the Java runtime environment, it might give rise to some unexpected issues.

If this has been running on a server, JBoss or Tomcat can be the culprits here. The Xen Virtual machine works just fine and is an identical disk image copy of the VMWare virtual machine. The virtual servers have 8G of RAM and MySQL has 6G allocated to it. I need to use VMWare though.

Operating systems frequently give programs more physical RAM than they ask for if they are not under memory pressure and think that it can reduce the amount of paging. The MySQL defaults have to balance performance with what is considered reasonable for what may be a development system with other applications needing to run alongside MySQL. In many cases, this will mean 4-8GB, but on virtual machines (or in my case with copies of mysqld running), there is a lot less available. The default configuration is designed to permit a MySQL server to start on a virtual machine that has approximately 512MB of RAM. Correctly configuring the use of available memory resources is one of the most important things you have to get right with MySQL for optimal performance and stability.

During the performance tuning, it is very important to find a current allocation and other statistics about the SQL Server Memory. Increasing the virtual machine memory size in more overhead memory usage. Memory usage is constantly high ( or greater) or constantly low ( or less). Free memory consistently is or less and swapping frequently occurs. The host probably is lacking the memory required to meet the demand.

In MySQL , the innodb_buffer_pool is a perfect candidate. I am running CentOS 6.