Incompatible changes in ArangoDB 3.3

The following incompatible changes have been made in ArangoDB 3.3:

If a non-existing vertex is referenced from a traversal, it is not desirable to logerrors as ArangoDB can store edges pointing to non-existing vertices (which is perfectly valid if the low-level insert APIs are used). As linking to non-existing verticesmay indicate an issue in/with the data model or the client application, the warning isregistered in the query so client applications have access to it.

• ArangoDB usernames must not start with the string .

• Server startup: the recommended value for the Linux kernel setting in /proc/sys/vm/max_map_count was increased to a value eight times as high as in 3.2. arangod compares at startup if the effective value of this setting is presumably too low, and it will issue a warning in this case, recommending to increase the value.

This is now more likely to happen than in previous versions, as the recommended value is now eight times higher than in 3.2. The startup warnings will look likethis (with actual numbers varying):

• The option has been removed from the arangorestore command. Using this option could have led to problems on the restore, with potential id conflicts between the originating server (the source dump server) and the target server (the restore server).

Miscellaneous

The minimum supported compiler for compiling ArangoDB from source is now g++ 5.4(bumped up from g++ 4.9). This change only affects users that compile ArangoDB ontheir own.