ArangoDB Server General Options

Help

--help

-h

Prints a list of the most common options available and then exits. In order to see all options use --help-all.

To receive the startup options in JSON format, pass the --dump-options flag. This will print out all options and exit.

Version

--version

-v

Prints the version of the server and exits.

--version-json

Prints the version of the server in JSON format and exits.

Daemon

--daemon

Runs the server as a daemon (as a background process). This parameter can only be set if the pid (process id) file is specified. That is, unless a value to the parameter pid-file is given, then the server will report an error and exit.

Default Language

--default-language language-name

The default language is used for sorting and comparing strings. The language value is a two-letter language code (ISO-639) or it is composed by a two-letter language code followed by a two letter country code (ISO-3166). For example: “de”, “en”, “en_US”, “en_UK”.

The default default-language is set to be the system locale on that platform.

ICU Language

Introduced in: v3.9.1

--icu-language language-name

The ICU language is also used for sorting and comparing strings. With this option however, you can get the sorting and comparing order exactly as it’s defined in the ICU standard. The language value can be a two-letter language code (ISO-639), a two-letter language code followed by a two letter country code (ISO-3166), or any other valid ICU locale definition. For example: “de”, “en”, “en_US”, “en_UK”, “de_AT@collation=phonebook”.

For example, for the Swedish language (sv) the correct ICU-based sorting order for letters is "a","A","b","B","z","Z","å","Ä","ö","Ö". To get this order, use --icu-language sv. In case of using --default-language sv, the sorting order will be "A","a","B","b","Z","z","å","Ä","Ö","ö".

Please note, that you can use only one of the language options (either --default-language or --icu-language). Setting both of them will result in an error.

Supervisor

--supervisor

Executes the server in supervisor mode. In the event that the server unexpectedly terminates due to an internal error, the supervisor will automatically restart the server. Setting this flag automatically implies that the server will run as a daemon. Note that, as with the daemon flag, this flag requires that the pid-file parameter will set.

unix> ./arangod --supervisor --pid-file /var/run/arangodb.pid /tmp/vocbase/
2012-06-27T15:58:28Z [10133] INFO starting up in supervisor mode

As can be seen (e.g. by executing the ps command), this will start a supervisor process and the actual database process:

unix> ps fax | grep arangod
10137 ?        Ssl    0:00 ./arangod --supervisor --pid-file /var/run/arangodb.pid /tmp/vocbase/
10142 ?        Sl     0:00  \_ ./arangod --supervisor --pid-file /var/run/arangodb.pid /tmp/vocbase/

When the database process terminates unexpectedly, the supervisor process will start up a new database process:

> kill -SIGSEGV 10142

> ps fax | grep arangod
10137 ?        Ssl    0:00 ./arangod --supervisor --pid-file /var/run/arangodb.pid /tmp/vocbase/
10168 ?        Sl     0:00  \_ ./arangod --supervisor --pid-file /var/run/arangodb.pid /tmp/vocbase/

User identity

--uid uid

The name (identity) of the user the server will run as. If this parameter is not specified, the server will not attempt to change its UID, so that the UID used by the server will be the same as the UID of the user who started the server. If this parameter is specified, then the server will change its UID after opening ports and reading configuration files, but before accepting connections or opening other files (such as recovery files). This is useful when the server must be started with raised privileges (in certain environments) but security considerations require that these privileges be dropped once the server has started work.

Observe that this parameter cannot be used to bypass operating system security. In general, this parameter (and its corresponding relative gid) can lower privileges but not raise them.

Group identity

--gid gid

The name (identity) of the group the server will run as. If this parameter is not specified, then the server will not attempt to change its GID, so that the GID the server runs as will be the primary group of the user who started the server. If this parameter is specified, then the server will change its GID after opening ports and reading configuration files, but before accepting connections or opening other files (such as recovery files).

This parameter is related to the parameter uid.

Process identity

--pid-file filename

The name of the process ID file to use when running the server as a daemon. This parameter must be specified if either the flag daemon or supervisor is set.

Console

--console

Runs the server in an exclusive emergency console mode. When starting the server with this option, the server is started with an interactive JavaScript emergency console, with all networking and HTTP interfaces of the server disabled.

No requests can be made to the server in this mode, and the only way to work with the server in this mode is by using the emergency console. Note that the server cannot be started in this mode if it is already running in this or another mode.

File copying mode

Introduced in: v3.9.4

--use-splice-syscall

This is a Linux-specific startup option that controls whether the Linux-specific splice() syscall should be used for copying file contents. While that syscall is generally available since Linux 2.6.x, it is also required that the underlying filesystem supports the splice operation. This is not true for some encrypted filesystems (e.g. ecryptfs), on which splice() calls can fail.

You can set the --use-splice-syscall startup option to false to use a less efficient, but more portable file copying method instead, which should work on all filesystems.

The startup option is not available on other operating systems than Linux.