Re: threads in cleaning up mode
Thanks to everyone for response. Any other views from any one is always
Senior Database Administrator
On Mon, Apr 4, 2016 at 7:51 PM, shawn l.green <shawn.l.green@xxxxxxxxxx>
> On 4/2/2016 10:36 AM, geetanjali mehra wrote:
>> Hi to all,
>> For many days, I am struggling with the problem of increasing history
>> length on mysql 5.6.29. Application that this server is running IOT based.
>> Also, this server has so many threads running in sleeping mode. SHOW
>> INNODB STATUS shows all these threads in *cleaning up* mode.
>> I tried all the options to reduce history list length. But it is
>> Below are the current settings of purge related threads:
>> innodb_max_purge_lag | 1000000 |
>> | innodb_max_purge_lag_delay | 0 |
>> | innodb_purge_batch_size | 1 |
>> | innodb_purge_threads | 8 |
>> Also, please let me know that whether cleaning up mode of threads and
>> history list length are correlated.
>> Anty help?
>> Best Regards,
>> Geetanjali Mehra
>> Senior Database Administrator
> No, the "cleaning up" status and your ever-increasing history are not
> related. The "cleaning up" status is a very low-impact bug in our code. We
> simply forgot to reset a flag at the end of that section of the code. It is
> not indicative of any ongoing operations.
> What has happened is one of those idle threads (the sleeping ones) has
> opened a transaction but never committed it. That is why your history list
> is never shrinking. As was already said in another response, this is an
> indication of poor client-side transaction management. If you start a
> transaction, you must always terminate it or situations like yours will
> happen. (This is also one of the dangers if someone changes autocommit=0
> and forgets to change it back.)
> Shawn Green
> MySQL Senior Principal Technical Support Engineer
> Oracle USA, Inc. - Integrated Cloud Applications & Platform Services
> Office: Blountville, TN
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