Strange debug prints appear in the system log I have two Drupal 7 sites on an Apache server that are printing strange debug messages in a system log. The sites are set in their vhost config to use error logs within each local site folder, like the following.


/var/www/site1.com/log/errorlog
/var/www/site1.com/html/[drupal installation]
/var/www/site2.com/log/error.log
/var/www/site2.com/html/[drupal installation]


These error logs are fine and happy, but I am seeing a large number of entries in /var/log/messages. These debug lines look like the following.


  Feb  5 08:51:56 server012 drupal:
  http://site1.com|1391619116|form_debug|5.10.83.11|http://site1.com/eform/submit/apply-for-a-program?pid=127||0||Array#012(#012
  [#parents] => Array#012        (#012        )#012#012    [#entity] =>
  Entityform Object#012        (#012            [uid] => #012
  [entityType:protected] => entityform#012
  [entityInfo:protected] => Array#012                (#012
  [label] => Entityform#012                    [entity class] =>
  Entityform#012                    [controller class] =>
  EntityformController#012                    [base table] =>
  entityform#012                    [fieldable] => 1#012
  [entity keys] => Array#012                        (#012
  [id] => entityform_id#012                            [bundle] =>
  type#012                            [revision] => #012
  )#012#012                    [bundles] => Array#012
  (#012                            [apply_for_a_program] => Array#012
  (#012                                    [label] => Apply for a thing
  or Ask a Question#012                                    [admin] =>
  Array#012                                        (#012
  [path] => admin/structure/entityform_types/manage/%entityform_type#012
  [real path] =>
  admin/structure/entityform_types/manage/apply_for_a_program#012
  [bundle argument] => 4#012
  [access arguments] => Array#012
  (#012                                                    [0] =>
  administer fields attached to entityform entities#012
  )#012#012                                            [original access
  arguments] => Array#012
  (#012





  Feb  5 08:51:48 server012 drupal: http://site2.com|1391619108|content|90.8.28.253|http://site2.com/fr/node/2/edit|http://site2.com/fr/node/2/edit|44|voir|page: updated Qui sommes nous?.


I've just been informed that /var/log/messages is linux "syslog". 


Why is Drupal printing to syslog?
Is this normal behavior?
Is there a setting to enable/disable syslog output?
That is what the Syslog module that comes with Drupal does. It is not enabled by default, but enabling it will cause what you are noticing.
The module doesn't have its own settings to disable logging the messages into the system logs; to stop that, just disable the module. Since you are not going to use it anymore, you can then uninstall it. (Don't delete its files, since they are copied every time you update Drupal.)