From: Rick James
Date: March 1 2012 9:23pm
Subject: Re: query_cache_type and Aborted Clients
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Which wait_timeout?  There are about 3 -- session vs global and 
interactive versus batch.

query_cache is (probably) totally independent of connections.

Aborted_clients is since startup, and will be "ever increasing" -- 
useless without dividing by something:

Aborted_clients/Uptime -- if > 1, then increase wait_timeout
Aborted_clients/Connections -- if > 30, then increase wait_timeout
Aborted_connects/Uptime -- when this is > 1, you might have a hacker 
trying to get in
Connections/Uptime -- if > 1, you might think about why you need to 
reconnect so often.

If a client sits there too long (more than wait_timeout), he will be 
disconnected.  30 seconds is plenty for web-type applications.

For investigating slow queries, please provide
* SHOW CREATE TABLE
* SHOW TABLE STATUS
* EXPLAIN SELECT ...
* SHOW VARIABLES LIKE '%buffer%'; and how much RAM do you have?

On 3/1/12 10:16 AM, Revathi Rangachari wrote:
> Hi
>
> Can anyone please let me know:
> (1) if query_cache_type is disabled, will it result in the number of 'Aborted Clients' getting increased.
>
> The possible explanation I have is that because the slow queries are taking a long time to execute, and the fact that the query_cache_type is also disabled, will it result in the clients getting disconnected from the server due to wait_timeout set both at the mysql level and application level?
>
> In my mysql setup the wait_timeout is 30 secs and the query_cache_type is disabled. I have an ever increasing number of Aborted Clients
>
>
> +------------------+--------+
> | Variable_name    | Value  |
> +------------------+--------+
> | Aborted_clients  | 661117 |
> | Aborted_connects | 156    |
> +------------------+--------+
>
> The wait_timeout at application level is 5 secs.
>
> Thanks in advance for any explanation on my query
> Revathi R
>
>
>
>

-- 
Rick James - MySQL Geek