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Search Results for: set max memory limit

Prevent MySQL downtime: Set max_user_connections

One of the common causes of downtime with MySQL is running out of connections. Have you ever seen this error? “ERROR 1040 (00000): Too many connections.” If you’re working with MySQL long enough you surely …

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10 MySQL settings to tune after installation

When we are hired for a MySQL performance audit, we are expected to review the MySQL configuration and to suggest improvements. Many people are surprised because in most cases, we only suggest to change a …

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MySQL server memory usage troubleshooting tips

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. As a …

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Limited disk space? Compact backups with Percona Xtrabackup 2.1

One very interesting feature, “Compact Backup,” is introduced in Percona XtraBackup 2.1. You can run “compact backups” with the  –compact option, which is very useful for those who have limited disk space to keep the MySQL …

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Can’t Create Thread: Errno 11 (A Tale of Two Ulimits)

Recently some of my fellow Perconians and I have noticed a bit of an uptick in customer cases featuring the following error message:

The canonical solution to this issue, if you do a bit …

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MySQL Wish for 2013 – Better Memory Accounting

With Performance Schema improvements in MySQL 5.6 I think we’re in the good shape with insight on what is causing performance bottlenecks as well as where CPU resources are spent. (Performance Schema does not accounts …

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Troubleshooting MySQL Memory Usage

One of the most painful troubleshooting tasks with MySQL is troubleshooting memory usage. The problem usually starts like this – you have configured MySQL to use reasonable global buffers, such as innodb_buffer_size, key_buffer_size etc, you …

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Distributed Set Processing with Shard-Query

Can Shard-Query scale to 20 nodes? Peter asked this question in comments to to my previous Shard-Query benchmark. Actually he asked if it could scale to 50, but testing 20 was all I could due …

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InnoDB Flushing: a lot of memory and slow disk

You may have seen in the last couple of weekly news posts that Baron mentioned we are working on a new adaptive flushing algorithm in InnoDB. In fact, we already have three such algorithms in …

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InnoDB memory allocation, ulimit, and OpenSUSE

I recently encountered an interesting case. A customer reported that mysqld crashed on start on OpenSUSE 11.2 kernel 2.6.31.12-0.2-desktop x86_64   with 96 GB RAM when the innodb_buffer_pool_size was set to anything more than 62 …

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