Not playing well with W3 Total Cache?

Here is what I have found when both BackWPUp and W3 Total Cache are activated:

WordPress version 3.5.1
BackWPup version 3.0.8 Get pro.
PHP version 5.3.13
MySQL version 5.1.39-log
PHP Memory limit 90M
WP memory limit 40M
WP Maximum memory limit 256M
Memory in use 57.75 MB

W3 Total Cache: v0.9.2.9

Database only backup to a Folder – All tasks complete OK
Database only backup to e-mail – All tasks complete OK
Database only backup to FTP – Database dump completes OK. Archive creation completes OK. Connection to FTP server completes OK, but only part of file is transferred to the FTP server before we see:

[17-Apr-2013 22:29:06 UTC] PHP Fatal error: Allowed memory size of 94371840 bytes exhausted (tried to allocate 445825 bytes) in /home/username/domainname.net/wp-content/plugins/w3-total-cache/lib/W3/ObjectCache.php on line 211

I also tried to purge all caches manually immediately before running BackWPUp – same result and failure at same point.

I have disabled W3 Total Cache for now until a workaround can be found (BackWPUp works flawlessly doing file/database backups when W3 Total Cache is not activated).

Thank you.

Hal

Daniel,

Yes, it is definitely a memory issue. I removed some other plugins and re-ran my database backup job and it worked OK. The WP_MAX_MEMORY_LIMIT was already set at 256MB, but the PHP MEMORY_LIMIT is at 90MB and that seems to be the limiting factor. I cannot increase that limit in my current shared hosting environment, so I will have to figure out which plugins I can either tune or not use.

Hal