# Persistent but intermittent page\_cleaner warnings in log
**URL:** https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486
**Category:** Percona Server for MySQL 5.7
**Created:** [August 1, 2018, 8:54pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486 "2018-08-01T20:54:42Z")
**Posts on this page:** 7
**Page:** 1
### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 1, 2018, 8:54pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/1 "2018-08-01T20:54:42Z")
Hi!
I have a new linode with 6 CPU cores. 16gig ram, SSD raid running Percona server 5.7.22-22 and Ubuntu 16.04. It is a slave to a Percona 5.6 server. Ever since building it, it has log warnings like the below, one or twice a day:
2018-07-28T12:42:37.554905Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 9873ms. The settings might not be optimal. (flushed=78, during the time.)
2018-07-30T01:09:12.360683Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 10967ms. The settings might not be optimal. (flushed=8, during the time.)
2018-07-30T11:18:56.042427Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 13259ms. The settings might not be optimal. (flushed=106, during the time.)
2018-07-30T22:29:27.797124Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 5557ms. The settings might not be optimal. (flushed=46, during the time.)
2018-07-31T14:37:31.821713Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 30181ms. The settings might not be optimal. (flushed=5, during the time.)
2018-07-31T21:53:04.710618Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 8186ms. The settings might not be optimal. (flushed=21, during the time.)
2018-08-02T00:23:22.393201Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 4223ms. The settings might not be optimal. (flushed=132, during the time.)
I monitor the server with datadog and new relic, and all aspects of CPU and IO are quiet at these times. At other much busier times, there are no warnings.
I’ve scoured forums to try and find an answer and been slowly tweaking down the innodb\_lru\_scan\_depth and up the innodb\_log\_file\_size. This doesn’t seem to have made much difference. Current settings in my cnf file are:
innodb\_flush\_method = O\_DIRECT
innodb\_log\_files\_in\_group = 2
innodb\_log\_file\_size = 256M
innodb\_flush\_log\_at\_trx\_commit = 2
innodb\_file\_per\_table = 1
innodb\_buffer\_pool\_size = 7G
innodb\_page\_cleaners = 6 # lower of CPU count or buffer pools if it cannot keep up
innodb\_lru\_scan\_depth = 256
Here are the full InnoDB settings:
[URL=“[page\_cleaner: 1000ms intended loop took... · GitHub](https://gist.github.com/jcrisp/c2465fb31e43a4c0a4ed913deb714e04)”][https://gist.github.com/jcrisp/c2465...ed913deb714e04[/URL]](https://gist.github.com/jcrisp/c2465...ed913deb714e04%5B/URL%5D)
Otherwise the database seems to working fine.
I’m hoping you might be able to give me some pointers to help resolve this, or let me know if it is not important?
Thanks very much!
James
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### Author:  [@vadimtk](https://forums.percona.com/u/vadimtk)
#### Post date: [August 2, 2018, 12:54pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/2 "2018-08-02T12:54:34Z")
Not sure what kind of SSD you have, but I would try still increase innodb\_log\_file\_size to say 4G.
Also I would try innodb\_io\_capacity=2500 and innodb\_io\_capacity\_max=4500
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### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 2, 2018, 5:03pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/3 "2018-08-02T17:03:47Z")
Thank you very much! I’ll give these a go and keep you posted on the results. James
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### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 6, 2018, 12:21am UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/4 "2018-08-06T00:21:55Z")
Hi Vadimtk! I tried with the increased innodb\_io\_capacity and innodb\_io\_capacity\_max and log size of 1G. I still got the warning again after 2 days (but maybe less frequent?). I’ve increased the innodb\_log\_file\_size to the full 4G now, and await to see if I get the message again. Thanks James
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### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 6, 2018, 6:39pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/5 "2018-08-06T18:39:51Z")
Hi again!
No luck, I’ve got another warning despite innodb\_log\_file\_size = 4G and innodb\_io\_capacity=2500 and innodb\_io\_capacity\_max=4500.
2018-08-06T10:12:38.116672Z 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 7950ms. The settings might not be optimal. (flushed=81, during the time.)
The setting changes don’t seem to have made much difference to the time it took to run. The machine is idle with low disk latency when the warning happens.
What else could we try?
Thanks
James
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### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 9, 2018, 5:34am UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/6 "2018-08-09T05:34:02Z")
Yes still getting about one every day or two:
2018-08-09T13:25:19.265377+10:00 0 [Note] InnoDB: page\_cleaner: 1000ms intended loop took 17914ms. The settings might not be optimal. (flushed=30, during the time.)
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### Author:  [@jcrisp](https://forums.percona.com/u/jcrisp)
#### Post date: [August 12, 2018, 7:29pm UTC](https://forums.percona.com/t/persistent-but-intermittent-page-cleaner-warnings-in-log/6486/7 "2018-08-12T19:29:40Z")
Hi Vadimtk! I think I managed to pin down a disk latency problem after all, with the VPS provider at the time of the latest page\_clearner error. It was quite short, but the page cleaner is every second. I’ve switched to a new host machine with same provider, and hoping this will solve it. I wanted to check though, are those settings you recommended good ones to stay with? Or should I slowly try and decrease the innodb\_log\_file\_size?
Thanks
James