MDS hangs on scanning

Issue

MDS stuck when scanning against large databases with the following symptoms:

• Fatal error: Allowed memory size of XXXXX bytes exhausted (tried to allocate XXXX bytes) in /opt/ai-bolit/imunify_dbscan.php 
• Imunify scan process stuck and can't progress.

Environment

• Imunify360 6.3.* and lower
• Malware Database Scanner
• Any supported panel
• Any supported OS

Solution

This is a known problem (internal id DEF-19230 can be tracked in changelog) that was fixed in Imunify360 6.4. It is enough to update Imunify360 on the server to the latest stable release to get MDS working correctly again: https://docs.imunify360.com/update/#gradual-roll-out 

If there is no possibility to install updates for Imunify360, the following workaround can be applied for version 6.3.* and lower:

1. Remove the immutable bit from the file /opt/ai-bolit/imunify_dbscan.php:

# chattr -i /opt/ai-bolit/imunify_dbscan.php

2. Increase the memory limit to 1024M in the /opt/ai-bolit/imunify_dbscan.php file, after the first <?php add the following and save the file.

ini_set('memory_limit', '1024M');

3. After the changes back immutable bit again:

# chattr +i /opt/ai-bolit/imunify_dbscan.php

Useful links

• https://docs.imunify360.com/update/#gradual-roll-out
• https://blog.imunify360.com/release-notes-imunify360-v.6.4