FromDual TechFeed (de)

InnoDB Buffer Pool

The InnoDB Buffer Pool is the memory area where the InnoDB Storage Engine caches its data and index blocks. Each InnoDB data and index block has a size of Innodb_page_size (16384 byte = 16 kbyte). The InnoDB Buffer Pool is configured in bytes with the innodb_buffer_pool_size variable. On a dedicated system the InnoDB Buffer Pool can be configured up to 80% of the systems physical RAM (free).

The innodb_buffer_pool_awe_mem_mb variable is relevant only on 32-bit Windows systems with more …

A bug report for the following problem has been opened: http://support.fromdual.com/bugs/view.php?id=40

A customer asked:

I would like to know if the FromDual Performance Monitor for MySQL works with Zabbix 2.0?

We do not know yet (June 2012). This is a project for this summer… We do not expect any problem if the Zabbix 2.0 interfaces have not changed significantly.

This customer kindly tested fpmmm on Zabbix 2.0 for us.

The customer reported:

In relation to FromDual Performance Monitor for MySQL, I’ve started a test today and I can import the xml files without any problem with Zabbix 2.0
To be …

Hi John,

MPM can work with any MySQL branch/fork. Some of the branches try to make their product unique by adding features or changing things. Because we are parsing the output of SHOW ENGINE INNODB STATUS amongst other things some values can become wrong over time when the output format is changed by the vendors.

The values you mention base most probably on the MySQL status information (SHOW GLOBAL STATUS) Innodb_data_fsyncs and Innodb_data_writes. So those should be correct on any MySQL branch/fork.

But I …

Daniel the Hazard wrote us:

just wanted to leave this complement to your GLB post: a init script for GLB that supports adding and removing targets

Thanks Daniel!

#!/bin/sh
#
# glbd          Start/Stop the Galera Load Balancer daemon.
#
# processname: glbd
# chkconfig: 2345 90 60
# description: GLB is a TCP load balancer similar to Pen. \
#              It lacks most of advanced Pen features, as \
#              the aim was to make a user-space TCP proxy which is \
#              as fast as …

See also Byobu.

Often support customers want to see what you do on their databases. For this screen is the ideal tool.

Screen commands typically look like this:

screen> Ctrl+a ?

This means press Ctrl+a, release Ctrl+a, press ? and NOT press Ctrl+a+? together. Often you can find Ctrl+A which is wrong. It is a lower case a!

Start first screen

Start and leave a screen:

shell> screen
screen> exit

or k for kill

screen> Ctrl+a k

Comment: Does not work if done with sudo, typically used with ssh.

A …

Some updates if you want to use bonding on CentOS 6:

Due to the fact that /etc/modprobe.conf has been deprecated in CentOS 6, the process of bonding network interfaces has changed a bit.

Now instead of defining your bond in your /etc/modprobe.conf, you define it in /etc/modprobe.d/bonding.conf [ 1 ].

Dear MySQL User,

With this newsletter we bring you up to date about MySQL and our Services.

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There are some news about the following topics:

• High-Availability(HA) with Galera Cluster for MySQL
• MySQL Performance Monitoring (MPM)
• MySQL Training in Essen and Berlin (Germany)
• 3^rd Level Support for MySQL
• Security holes in MySQL
• Technical information …

Hello Matthew,

In the proposed way it does not work. In Zabbix a host name must be unique. What you call db_label is the Zabbix hostname.

We have for our MaaS customers the following constellations:

• Several companies
• Master/Slave set-ups
• Galera Cluster set-ups
• Several MySQL instances (mysqld) per server.

We recommend to use the db_label as follows:

[Company.Server_name.Db_fantasy_name]

In your case you possibly can omit the Company tag. So we have:

[Server_A.Prod]

[Server_B.Failover] …

If you need some more information about FromDual here are some resources:

• The Blogs of FromDual employees.
• Our MySQL, MariaDB, and Galera Cluster Forum.
• FromDual presentations hold at various conferences and events.
• Our FromDual software download page.
• FromDual TV.
• Photos of FromDual events.
• and the SiteMap.

FromDual product documentation

• MyEnv Installation Guide
• Ops Center Installation Guide
• Ops Center User Guide
• Performance Monitor Installation Guide
• Performance Monitor User Guide
• Backup and Recovery …

Hello Wills,

No problem. I am lucky we finally found it. Any improvement suggestions are welcome!

Oli

Hello Wills,

First I would check if the host ‘util-mysql0’ matches EXACTLY the hostname in Zabbix server. That is the typical problem. Are you sure this specific item (FromDual.MySQL.mysql.version) exists under this host?

I still do not get what you mean with active and passive. Can you please elaborate?

Best regards, Oli

Hello Wills,

What about uploading data of some of the relevant modules (mysql or innodb for example)? Have you changed something except upgrading the mpm agent?

With: Monitoring -> Last data you can see if items are uploaded.

You can simulate this manually as follows:

/usr/bin/zabbix_sender –zabbix-server util-zabbix0 –port 10051 –host ‘util-mysql0’ –key FromDual.MySQL.mysql.version –value ’test version’ -vv

Then you should get something like: …

Hi Wills,

This is OK because the key does not exist in any template.

  # This tag does NOT exist in templates!!!
  my $lKey    = 'FromDual.server.check';

Did it stop before you did the upgrade or did it stop when you did the upgrade?

Can you set Debug = 4 in the mpm configuration file and let us know the output? Is the zabbix_agent triggered at all?

Regards, Oli

https://github.com/ioggstream/ndb_size.pl/tree/add_ondisk

Hello Cédric,

OK. I see. 5.1 is a bit outdated now… Most of our customers are going to 5.5 now or are already on it. So we have to focus on the future.

Oli

Hello Cédric,

What the monitor does is the following:

SELECT SUM(compress_time) AS compress_time, SUM(uncompress_time) AS uncompress_time
  FROM information_schema.INNODB_CMP

The MySQL documentation states in chapter The INFORMATION_SCHEMA INNODB_CMP and INNODB_CMP_RESET Tables:

COMPRESS_TIME: Total time in seconds spent in attempts to compress B-tree pages of the size PAGE_SIZE.
UNCOMPRESS_TIME: Total time in seconds spent in uncompressing B-tree pages of the size PAGE_SIZE.

So we store the delta and can …

zabbix_sender was capable to connect and send (sent: 1) but processing the item failed (Processed 0, Failed 1)

This can happen because of the following reasons:

1. The host name does not match
2. The item does not exist
3. There is a bug

The second problem imho is independent from the first one (except you hit a bug). Zabbix server could not reach Zabbix agent for some reasons. We also get this error from time to time.

So it could be that the bug you described causes this or some other reasons mentioned here: …

Hello

I have successfully installed and configured zabbix to work with your performance monitoring. However, every once in a while, the graphs in zabbix do not display any information. It seems when I invoke FromDualMySQLagent.pl things go back to normal. Do I need to setup a cron to refresh the data?

I have included the following line in /etc/zabbix/zabbix_agentd/userparameter_mysql.conf:

UserParameter=FromDual.MySQL.check,/usr/local/mysql_performance_monitor/FromDualMySQLagent.pl …