How to solve mysql warning: "InnoDB: page_cleaner: 1000ms intended loop took XXX ms. The settings might not be optimal "?
<p>I ran a mysql import mysql dummyctrad &lt; dumpfile.sql on server and its taking too long to complete. The dump file is about 5G. The server is a Centos 6, memory=16G and 8core processors, mysql v 5.7 x64-</p>

<p>Are these normal messages/status "waiting for table flush" and the message <code>InnoDB: page_cleaner: 1000ms intended loop took 4013ms. The settings might not be optimal</code> </p>

<p>mysql log contents</p>

<pre><code>2016-12-13T10:51:39.909382Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4013ms. The settings might not be optimal. (flushed=1438 and evicted=0, during the time.)
2016-12-13T10:53:01.170388Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4055ms. The settings might not be optimal. (flushed=1412 and evicted=0, during the time.)
2016-12-13T11:07:11.728812Z 0 [Note] InnoDB: page_cleaner: 1000ms intended loop took 4008ms. The settings might not be optimal. (flushed=1414 and evicted=0, during the time.)
2016-12-13T11:39:54.257618Z 3274915 [Note] Aborted connection 3274915 to db: 'dummyctrad' user: 'root' host: 'localhost' (Got an error writing communication packets)
</code></pre>

<p>Processlist:</p>

<pre><code>mysql&gt; show processlist \G;
*************************** 1. row ***************************
     Id: 3273081
   User: root
   Host: localhost
     db: dummyctrad
Command: Field List
   Time: 7580
  State: Waiting for table flush
   Info: 
*************************** 2. row ***************************
     Id: 3274915
   User: root
   Host: localhost
     db: dummyctrad
Command: Query
   Time: 2
  State: update
   Info: INSERT INTO `radacct` VALUES (351318325,'kxid ge:7186','abcxyz5976c','user100
*************************** 3. row ***************************
     Id: 3291591
   User: root
   Host: localhost
     db: NULL
Command: Query
   Time: 0
  State: starting
   Info: show processlist
*************************** 4. row ***************************
     Id: 3291657
   User: remoteuser
   Host: portal.example.com:32800
     db: ctradius
Command: Sleep
   Time: 2
  State: 
   Info: NULL
4 rows in set (0.00 sec)
</code></pre>

<p><strong>Update-1</strong></p>

<p><a href="https://bugs.mysql.com/bug.php?id=81899" rel="noreferrer">mysqlforum</a> ,<a href="http://dev.mysql.com/doc/refman/5.7/en/innodb-parameters.html#sysvar_innodb_lru_scan_depth" rel="noreferrer">innodb_lru_scan_depth</a></p>

<p>changing innodb_lru_scan_depth value to 256 have improved the insert queries execution time + no warning message in log, the default was innodb_lru_scan_depth=1024;</p>

<p><code>SET GLOBAL innodb_lru_scan_depth=256;</code></p>