How To Fix HH047 - Check the values of 'page cleaner' and 'LRU_MAX_DIRTY'

HH047 - Overview

• Message type: E = Error

• Message class: HH - (Long) text for check tool 'infcfgcheck'

• Message number: 047

• Message text: Check the values of 'page cleaner' and 'LRU_MAX_DIRTY'

What causes this issue?

This is a single 'performance' check and therefore does not
describe a critical system status. It is neither necessary nor
time-critical to perform the steps described below, but they could
help improve the overall performance of your R/3 System.

The system issues an error message and will not allow you to continue with this transaction until the error is resolved.

'Foreground writes' occurred since the last time you started the
database. A 'foreground write' is necessary if an Informix user
thread (' light-weight process) does not find an empty or unmodified
buffer in Shared Memory therefore buffers have to be 'emptied' to
disk. This is very time-consuming and should be avoided if possible.

System Response

How to fix this error?

Check the number of 'page cleaners' (ONCONFIG parameter 'CLEANERS')
and ONCONFIG parameter 'LRU_MAX_DIRTY' after reading Note 41360.
To change an ONCONFIG parameter, edit the file
'$INFORMIXDIR/etc/$ONCONFIG' as user 'informix'.
CAUTION: The change will only become active when the database has
been started up.

Error message extract from SAP system. Copyright SAP SE.

Smart SAP Assistant

• What is the cause and solution for SAP error message HH047 - Check the values of 'page cleaner' and 'LRU_MAX_DIRTY' ?

  The SAP error message HH047 indicates an issue related to the database buffer management, specifically concerning the parameters 'page cleaner' and 'LRU_MAX_DIRTY'. This error typically arises in the context of SAP HANA or other database systems where memory management and data consistency are critical.
  
  Cause:
  
  
  Page Cleaner: The page cleaner is responsible for writing dirty pages (modified data) from the memory to the disk. If the page cleaner is not functioning correctly or is misconfigured, it can lead to performance issues or data consistency problems.
  
  
  LRU_MAX_DIRTY: This parameter defines the maximum number of dirty pages that can be held in memory. If this limit is reached, it can prevent new data from being written to memory, leading to potential errors or performance degradation.
  
  
  
  Solution:
  
  
  Check Configuration: Review the configuration settings for the page cleaner and LRU_MAX_DIRTY. Ensure that they are set to appropriate values based on your system's workload and memory capacity.
  
  
  Increase LRU_MAX_DIRTY: If the