Configuration File

ApertureDB uses a configuration file (following a JSON format) that can be specified when starting the server using the “-cfg” flag:

./aperturedb -cfg config.json

If no configuration file is specified, ApertureDB will try to open the default file (config.json), and will fail to initiate if the file is not found.


All the parameters in the configuration file are optional, as ApertureDB has default values for all of them:

Parameter Explanation Default
port TCP port for incoming connections 55555
max_simultaneous_clients Number of max simultaneous connections open 500
db_root_path Path to the root folder where all filed/objects will be stored db
images_path Path to folder where images (all formats) will be stored images (db/images)
blobs_path Path to folder where blobs will be stored blobs (db/blobs)
descriptors_path Path to folder where descriptors will be stored descriptors (db/descriptors)
create_parameters Object used to specify parameters used at creation time N/A
create_parameters[“pmgd_num_allocators”] Number of allocators when creating a new PMGD graph (this will only be used * - when creating a new graph, and ignored if the graph already exist) 1
create_parameters[“pmgd_max_strlen”] Maximum length of strings for class and properties name 64
create_parameters[“pmgd_node_size”] Size of the Node representation in memory, in bytes 64
create_parameters[“pmgd_edge_size”] Size of the Edge representation in memory, in bytes 32
create_parameters[“pmgd_txtable_size”] Size of transaction (TX) table in KB. Determines max concurrent TXs. 4
create_parameters[“pmgd_journal_size”] Total in-memory journal space for all TXs, in MB. Determines space per TX. 128
log_path Directory where logs will be placed. “/tmp”
log_level Levels INFO, WARNING, ERROR, and FATAL are 0, 1, 2, and 3, respectively. 1 (WARNING)
verbose_log_level Verbosity level beyond INFO, for debugging. Will set log_level = 0. Check Google glog documentation for details. -1 (no verbosity beyond INFO)
log_cerr_threshold Specify level of logging which will also be sent to stderr 3 (FATAL)
collect_thread_interval Number of seconds between collecting system status information. 1
collect_interval_set An array of look-back intervals, in seconds, over which system status information is averaged. [5,10,30,120]
query_retry_count Timed-out query will be retried that many times or until it succeeds, whichever comes first. 30
resources_check_sleep Number of seconds between resource utilization checks. 2
resources_check_mem_limit Limit on percentage of memory utilization after which queries are stopped. 93

Config File Example

Here is an example configuration file that has all the parameters with its default values. There is no need to specify any parameter if you want to work with default values.

// ApertureDB Config File
// All parameters show the default values.
    // Network
    "port": 55555,
    "max_simultaneous_clients": 500,
    "max_connection_message_size_mb": 256,

    // DB paths
    "db_root_path":     "db",
    "blobs_path":       "db/blobs",
    "images_path":      "db/images",
    "videos_path":      "db/videos",
    "descriptors_path": "db/descriptors",

    // Log parameters
    "log_path":           "/tmp/",
    "log_level":          1,        // Warnings only
    "verbose_log_level":  0,
    "log_cerr_threshold": 3,

    // Batching parameters
    "batch_cleaner_interval":  10,
    "batch_time_to_live":      60,

    // Resource Check  parameters
    "resources_check_sleep":     2,
    "resources_check_mem_limit": 93,

    // Telemetry collection parameters
    "collect_thread_interval": 1,
    "collect_interval_set":   [5,10,30,120]

    // Timed-out queries
    "query_retry_count: 32,

    // Parameters used only when creating a new db
    "create_parameters": {

        "pmgd_num_allocators": 1,
        "pmgd_max_strlen":     64,
        "pmgd_node_size":      64,
        "pmgd_edge_size":      32,
        "pmgd_locale_name":    ""

    "index": [

    "more-info": "ApertureDB"

Default Directories Structure

By default, ApertureDB will create a directory structure as follows:

├── blobs
├── descriptors
├── graph
└── images
    ├── jpg
    ├── png
    └── tdb
└── videos