Sometimes CCK custom fields get lost although they appear normally in the database

Question

I have pressflow 6.22.

When the editors try to create new node, they lose what they have inserted in CCK custom fields. I have checked node_load and the result is missing those values as well.

I checked the tables and the result is as below:

mysql> select * from content_field_headline_image where nid=380320\G
*************************** 1. row ***************************
                                  vid: 380322
                                  nid: 380320
  field_headline_image_imceimage_path: http://mywebsite.com/sites/default/files/im/Maven.jpg
 field_headline_image_imceimage_width: 0
field_headline_image_imceimage_height: 0
   field_headline_image_imceimage_alt: Maven
                                delta: 0

but this image doesn't appear in node_load result as well as in the preview of the node itself.
##EDIT##

I fixed it when I flush_all for memcache !!

Any idea of how to disable memcache for logged-in users only??

note:cache mode is disabled (cache mode in admin>>performance)

Thanks for your help

Answer 1

Even though some fields appear correct in the DB, they don't always load up into the edit view, I've noticed similar oddness long ago when trying to replace some image assist tags in the database directly with a php script.

In our case, the edit view (node/edit) begun showing correct data after we purged all caches.

To solve your problem, read and understand how Memcached works from http://en.wikipedia.org/wiki/Memcached -- When making manual DB edits, you must let Memcached know that you've made modifications to tables, this functionality is built into Drupal database handling, hence you'll never notice it when working directly from Drupal, but if you are making custom update queries into the tables, you must let Memcached know there was a change. Was a bit of a surprise to me since I thought it just automaticly works in the background. :)

See the example code part from the wikipedia page how to do it.

..and if you don't use custom update queries to modify those CCK fields, I suspect there must be some sort of a bug in Pressflow itself. Do the changes propagate into the edit view after few hours? Apart from this, there's not really enough info to dig in deeper :/