Managing Connections To Hosts

[smdb]

I work for a company that does a tremendous amount of command line MySQL work, and I'm looking for an application to facilitate that. It appears your product is a great fit.

One huge concern for our DBA is limiting the number of connections any user generates. We have had problems with hosts reaching their max connection limit, and we want to ensure that no user spawns more connections than they strictly need. With the command line client this is relatively easy as each connection a user makes must be very explicit. So some questions about your product:

• Are any background connections ever made?
• Is it possible to ensure only one connection per host is active at any given time?
• Is it possible to ensure only hosts that are explicitly connected to by the user are connected to?
• If the host kills the connection, is it possible to avoid the client automatically re-connecting?

Anyhow, if we can find a product to fit our needs we would be looking to purchase 50-70 licenses. I'm not making any promises (I haven't tried the product yet, and I haven't reviewed your competitors yet either), but just want to let you know where we're coming from.

[Sayan Chaliha]

Hi,

I suppose you are referring to SQLyog. This forum is for MONyog — MySQL monitor. I'll move this topic to the SQLyog forums, and I'm sure you have a reply pretty soon!

[smdb]

'Sayan wrote on '25:

Hi,

I suppose you are referring to SQLyog. This forum is for MONyog — MySQL monitor. I'll move this topic to the SQLyog forums, and I'm sure you have a reply pretty soon!

Thanks Sayan, I definitely posted in the wrong forum.

[peterlaursen]

Are any background connections ever made?

Yes, specific functionalities run in their own thread and use a seperate connection. Imports, exports, data sync for instance. All SJA modules will use one thread for the GUI wizard and one for the executable.  Addditionally autocomplete functionlaity is using its own thread/connection.  As I calculate that means that there can be up to 4 connections at a time (example: the main window, the autocompelte thread, a GUI wizard thread and a SJA executable)

You will not find i GUI client working properly in a single conenction I believe.  Problem is that the MySQL client/server protocol does not support parallellism.  Once a query is sent from a client the client can only wait for the server response arriving in that conenction.

Is it possible to ensure only one connection per host is active at any given time?

This can be defined when creating a user or a global setting can be defined in server configuration.  In both cases it is a server-side setting.  Once defined with any client it has effect for all clients.  Start here: http://dev.mysql.com/doc/refman/5.1/en/user-resources.html

Is it possible to ensure only hosts that are explicitly connected to by the user are connected to?

I do not understand the question.  But again such functionalities will have to be server functionalities and not client functionalities.

If the host kills the connection, is it possible to avoid the client automatically re-connecting?

No.  Again you are asking for client functionalities that will have to be server functionalities. 

We have had problems with hosts reaching their max connection limit

Then raise the max_connections setting in server configuration. Refer to: http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html#sysvar_max_connections

[peterlaursen]

Additionally a user may open an unlimited connection windows to same server from one SQLyog instance (from 'file' menu) or even multiple program instances can run simultaneously.

[smdb]

'peterlaursen' wrote on '25:

Is it possible to ensure only one connection per host is active at any given time?

This can be defined when creating a user or a global setting can be defined in server configuration. In both cases it is a server-side setting. Once defined with any client it has effect for all clients. Start here: http://dev.mysql.com…-resources.html

What happens to SQLyog if you set it up this way given it requires up to for connections? Will it function?

'peterlaursen' wrote on '25:

If the host kills the connection, is it possible to avoid the client automatically re-connecting?

I think I'm not being clear here: when the host kills a connection from a standard command line client, the connection is not renewed until the user executes another command. What happens with SQLyog? Does the client automatically reconnect when it is booted by the host without user intervention? Or must the user do something? Basically, we don't want a whole bunch of idle clients eating up connections.

'peterlaursen' wrote on '25:

Then raise the max_connections setting in server configuration. Refer to: http://dev.mysql.com/doc/refman/5.1/en/server-system-variables.html#sysvar_max_connections

This unfortunately is not an option for us for various reasons.

Thanks for your informative replies.

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