Incompatible changes in ArangoDB 2.7

    is now a keyword in AQL.

    AQL queries that use DISTINCT (in lower, upper or mixed case) as an identifier (i.e. as a variable, a collection name or a function name) will stop working. To make such queries working again, each occurrence of DISTINCT in an AQL query should be enclosed in backticks.This will turn DISTINCT from a keyword into an identifier again.

    The AQL function SKIPLIST() has been removed in ArangoDB 2.7. This function was deprecated inArangoDB 2.6. It was a left-over from times when the query optimizer wasn’t able to use skiplist indexes together with filters, skip and limit values. Since this issue been fixed since version 2.3, there is no AQL replacement function for SKIPLIST. Queries that use the SKIPLIST function can be fixed by using the usual combination of FOR, FILTER and LIMIT, e.g.

    Foxx changes

    The assets property is no longer supported in Foxx manifests and is scheduled to be removed in a future version of ArangoDB. The files property can still be used to serve static assets but it is recommended to use separate tooling to compile and bundle your assets.

    Manifest scripts

    The properties setup and teardown have been moved into the scripts property map:



    Foxx Queues

    Function-based Foxx Queue job types are no longer supported. To learn about how you can use the new script-based job typessee the .

    The jwt and type options have been removed from the activateSessions API.

    If you want to replicate the behavior of the jwt option you can use the JWT functions in the crypto module. A JWT-based session storage that doesn’t write sessions to the database is available as the sessions-jwt app in the Foxx app store.

    The session type is now inferred from the presence of the cookie or options (allowing you to enable support for both). If you want to use the default settings for cookie or header you can pass the value true instead.



    Request module

    The module org/arangodb/request uses an internal library function for sending HTTPrequests. This library functionally unconditionally set an HTTP header Accept-Encoding: gzipin all outgoing HTTP requests, without client code having to set this header explicitly.

    This has been fixed in 2.7, so Accept-Encoding: gzip is not set automatically anymore.Additionally the header User-Agent: ArangoDB is not set automatically either. Ifclient applications rely on these headers being sent, they are free to add it whenconstructing requests using the request module.

    The function is also affected by this change. Again, the headercan be added here if required by passing it via a headers sub-attribute in thethird parameter (options) to this function.

    The filenames in dumps created by arangodump now contain not only the name of the dumped collection, but also an additional 32-digit hash value. This is done to prevent overwriting dump files in case-insensitive file systems when there exist multiple collections with the same name (but with different cases).

    This change leads to changed filenames in dumps created by arangodump. If any clientscripts depend on the filenames in the dump output directory being equal to the collectionname plus one of the suffixes .structure.json and .data.json, they need to be adjusted.

    Starting with ArangoDB 2.7, the file names will contain an underscore plus the 32-digitMD5 value (represented in hexadecimal notation) of the collection name.

    For example, when arangodump dumps data of two collections test and Test, the filenames in previous versions of ArangoDB were:

    • test.structure.json (definitions for collection test)
    • (data for collection test)
    • Test.structure.json (definitions for collection Test)
    • (data for collection Test)

    In 2.7, the filenames will be:

    • (data for collection _test)
    • (definitions for collection _Test)
    • (data for collection _Test)

    Starting / stopping

    When starting arangod, the server will now drop the process privileges to the specified values in options —server.uid and —server.gid instantly after parsing the startup options.

    The default privileges for user arangodb will not be sufficient for bindingto port numbers lower than 1024. To have an ArangoDB 2.7 bind to a port number lower than 1024, it needs to be started with either a different privileged user,or the privileges of the arangodb user have to raised manually beforehand.

    Additionally, Linux startup scripts and systemd configuration for arangod now will adjust the NOFILE (number of open files) limits for the process. The limitvalue is set to 131072 (128k) when ArangoDB is started via start/stop commands.The goal of this change is to prevent arangod from running out of availablefile descriptors for socket connections and datafiles.

    arangod will now actually close lingering client connections when idle for at least the duration specified in the —server.keep-alive-timeout startup option.

    In previous versions of ArangoDB, idle connections were not closed by the server when the timeout was reached and the client was still connected. Now the connection is properly closed by the server in case of timeout. Clientapplications relying on the old behavior may now need to reconnect to theserver when their idle connections time out and get closed (note: connections being idle for a long time may be closed by the OS or firewalls anyway - client applications should be aware of that and try to reconnect).

    Option changes

    Configure options removed

    The following options for configure have been removed because they were unusedor exotic:

    • —enable-timings
    • —enable-figures

    The following configuration options have been added in 2.7:

    • —database.query-cache-max-results: sets the maximum number of results in AQL query result cache per database
    • —database.query-cache-mode: sets the mode for the AQL query results cache. Possible values are on, off and demand. The default value is off

    Simple queries

    Many simple queries provide a skip() function that can be used to skip over a certain numberof documents in the result. This function allowed specifying negative offsets in previous versionsof ArangoDB. Specifying a negative offset led to the query result being iterated in reverse order,so skipping was performed from the back of the result. As most simple queries do not provide aguaranteed result order, skipping from the back of a result with unspecific order seems a ratherexotic use case and was removed to increase consistency with AQL, which also does not providenegative skip values.

    Negative skip values were deprecated in ArangoDB 2.6.

    Tasks API

    The undocumented function addJob() has been removed from the org/arangodb/tasks module inArangoDB 2.7.

    The following HTTP REST API methods for runtime manipulation of server endpoints have beenremoved in ArangoDB 2.7:

    • POST /_api/endpoint: to dynamically add an endpoint while the server was running
    • DELETE /_api/endpoint: to dynamically remove an endpoint while the server was running

    This change also affects the equivalent JavaScript endpoint manipulation methods available in Foxx. The following functions have been removed in ArangoDB 2.7: