3.13. Miscellaneous Parameters

    • compression_level

      Defines zlib compression level for the attachments from 1 (lowest, fastest) to 9 (highest, slowest). A value of 0 disables compression:

    • compressible_types

      Since compression is ineffective for some types of files, it is possible to let CouchDB compress only some types of attachments, specified by their MIME type:

      1. [attachments]
      2. compressible_types = text/*, application/javascript, application/json, application/xml

    3.13.2. Statistic Calculation

    [stats]

    • interval

      Interval between gathering statistics in seconds:

      1. [stats]
      2. interval = 10

    [uuids]

    • algorithm

      Changed in version 1.3: Added utc_id algorithm.

      CouchDB provides various algorithms to generate the UUID values that are used for document _id’s by default:

      1. [uuids]
      2. algorithm = sequential

      Available algorithms:

      • random: 128 bits of random awesome. All awesome, all the time:

        1. {
        2.     "uuids": [
        3.         "5fcbbf2cb171b1d5c3bc6df3d4affb32",
        4.         "9115e0942372a87a977f1caf30b2ac29",
        5.         "3840b51b0b81b46cab99384d5cd106e3",
        6.         "b848dbdeb422164babf2705ac18173e1",
        7.         "b7a8566af7e0fc02404bb676b47c3bf7",
        8.         "a006879afdcae324d70e925c420c860d",
        9.         "5f7716ee487cc4083545d4ca02cd45d4",
        10.         "35fdd1c8346c22ccc43cc45cd632e6d6",
        11.         "97bbdb4a1c7166682dc026e1ac97a64c",
        12.         "eb242b506a6ae330bda6969bb2677079"
        13.     ]
        14. }

      • sequential: Monotonically increasing ids with random increments. The first 26 hex characters are random, the last 6 increment in random amounts until an overflow occurs. On overflow, the random prefix is regenerated and the process starts over.

        1. {
        2.     "uuids": [
        3.         "4e17c12963f4bee0e6ec90da54804894",
        4.         "4e17c12963f4bee0e6ec90da5480512f",
        5.         "4e17c12963f4bee0e6ec90da54805c25",
        6.         "4e17c12963f4bee0e6ec90da54806ba1",
        7.         "4e17c12963f4bee0e6ec90da548072b3",
        8.         "4e17c12963f4bee0e6ec90da54807718",
        9.         "4e17c12963f4bee0e6ec90da54807754",
        10.         "4e17c12963f4bee0e6ec90da54807e5d",
        11.         "4e17c12963f4bee0e6ec90da54808d28"
        12.     ]

      • utc_random: The time since Jan 1, 1970 UTC, in microseconds. The first 14 characters are the time in hex. The last 18 are random.

        1. {
        2.     "uuids": [
        3.         "04dd32b3af699659b6db9486a9c58c62",
        4.         "04dd32b3af69bb1c2ac7ebfee0a50d88",
        5.         "04dd32b3af69d8591b99a8e86a76e0fb",
        6.         "04dd32b3af69f4a18a76efd89867f4f4",
        7.         "04dd32b3af6a1f7925001274bbfde952",
        8.         "04dd32b3af6a3fe8ea9b120ed906a57f",
        9.         "04dd32b3af6a5b5c518809d3d4b76654",
        10.         "04dd32b3af6a78f6ab32f1e928593c73",
        11.         "04dd32b3af6a99916c665d6bbf857475",
        12.         "04dd32b3af6ab558dd3f2c0afacb7d66"
        13.     ]
        14. }

      • utc_id: The time since Jan 1, 1970 UTC, in microseconds, plus the utc_id_suffix string. The first 14 characters are the time in hex. The string value is appended to these.

        1. {
        2.     "uuids": [
        3.         "04dd32bd5eabcc@mycouch",
        4.         "04dd32bd5eabee@mycouch",
        5.         "04dd32bd5eac05@mycouch",
        6.         "04dd32bd5eac28@mycouch",
        7.         "04dd32bd5eac43@mycouch",
        8.         "04dd32bd5eac58@mycouch",
        9.         "04dd32bd5eac6e@mycouch",
        10.         "04dd32bd5eac84@mycouch",
        11.         "04dd32bd5eac98@mycouch",
        12.         "04dd32bd5eacad@mycouch"
        13.     ]
        14. }

      Note

      Impact of UUID choices: the choice of UUID has a significant impact on the layout of the B-tree, prior to compaction.

      For example, using a sequential UUID algorithm while uploading a large batch of documents will avoid the need to rewrite many intermediate B-tree nodes. A random UUID algorithm may require rewriting intermediate nodes on a regular basis, resulting in significantly decreased throughput and wasted disk space space due to the append-only B-tree design.

      It is generally recommended to set your own UUIDs, or use the sequential algorithm unless you have a specific need and take into account the likely need for compaction to re-balance the B-tree and reclaim wasted space.

    • utc_id_suffix

      New in version 1.3.

    • max_count

      New in version 1.5.1.

      No more than this number of UUIDs will be sent in a single request. If more UUIDs are requested, an HTTP error response will be thrown.

      1. [uuid]
      2. max_count = 1000

    3.13.4. Vendor information

    [vendor]

    New in version 1.3.

    CouchDB distributors have the option of customizing CouchDB’s welcome message. This is returned when requesting GET /.

    1. name = The Apache Software Foundation
    2. version = 1.5.0

    [csp]

    You can configure header for Fauxton, attachments and show/list functions separately. See for more details on CSP.

    3.13.6. Configuration of Database Purge

    [purge]

    • max_document_id_number

      New in version 3.0.

      Sets the maximum number of documents allowed in a single purge request:

      1. [purge]
      2. max_document_id_number = 100

    • max_revisions_number

      New in version 3.0.

      Sets the maximum number of accumulated revisions allowed in a single purge request:

      1. [purge]
      2. max_revisions_number = 1000

    • index_lag_warn_seconds

      New in version 3.0.

      Sets the allowed duration when index is not updated for local purge checkpoint document. Default is 24 hours:

      1. [purge]
      2. index_lag_warn_seconds = 86400

    [prometheus]

    • additional_port

      New in version 3.2.

      Sets whether or not to create a separate, non-authenticated port (default is false):

      1. [prometheus]
      2. additional_port = true

    • bind_address

      New in version 3.2.

      The IP address to bind:

      1. [prometheus]

    • port

      New in version 3.2.

      [prometheus] port = 17986