Administering the MapR Data Access Gateway

The MapR Data Access Gateway is a service that acts as a proxy and gateway for translating requests between lightweight client applications and the MapR cluster. This section describes considerations when upgrading the service, how to modify configuration settings, and how to administer and manage the service.

Installing the Data Access Gateway Service

The MapR Data Access Gateway is installed when you install MapR Database in the MapR installer. To manually install the service, see Installing MapR Data Access Gateway. For installation guidance, see Understanding the MapR Data Access Gateway.

Upgrading the Data Access Gateway Service

When the Data Access Gateway receives a shutdown request, it stops accepting new requests and returns an error to the client. Any in-progress requests are allowed to complete before shutting down the service. This allows you to perform rolling upgrades.

Modifying Configuration Settings for the Data Access Gateway Service

Logging Properties

The MapR Data Access Gateway uses standard Log4J configuration to control its logging. The log4j properties are in the file /opt/mapr/data-access-gateway/conf/log4j2.xml on nodes where you have installed the service. After modifying any properties on a node, restart the service. See Administering the Data Access Gateway Service for details.

The file /opt/mapr/data-access-gateway/logs/data-access-gateway.log contains the log data.

Application Properties

You can configure MapR Data Access Gateway properties by modifying the file /opt/mapr/data-access-gateway/conf/properties.cfg on nodes where you have installed the service.

The following table lists the properties you can set:

Property Name Default Description
auth.token.expiration 1800 Expiration time (in seconds) for the authentication token
grpc.service.ojai.query.result-limit 5000 Limit on the number of documents returned in retrieval requests using the Node.js and Python OJAI clients
grpc.service.port 5678 Port number gRPC clients use to connect to the Data Access Gateway. The Node.js and Python OJAI clients are gRPC clients.
grpc.service.ssl.enabled cluster Controls whether TLS is enabled for the gRPC Service

Values: cluster|true|false

If set to cluster:
  • TLS is enabled if your MapR cluster is secure
  • TLS is disabled if your MapR cluster is not secure

When TLS is enabled, the SSL provider is OpenSSL.

rest.https.port 8243 Port number used to connect to the Data Access Gateway using HTTPS
rest.result.limit 5000 Limit on the number of documents returned in retrieval requests using the MapR Database JSON REST API

There is also a configuration file /opt/mapr/data-access-gateway/conf/ojai-config.json for parameters used by Data Access Gateway clients:

  • MapR Database JSON REST API
  • Node.js OJAI
  • Python OJAI

A parameter you can modify is the client sort limit:

{
    "ojai": { 
        "mapr": {
            "query": {
                "max-client-sort-limit": 6000
            }
        }
    }
}

See Comparisons and Sorts in OJAI Queries for details about why you may want to modify this parameter.

After modifying any parameters on a node, restart the service, as described in the Administering the Data Access Gateway Service section.

Warden Configuration

The warden configuration for the MapR Data Access Gateway is in the file /opt/mapr/data-access-gateway/conf/warden.data-access-gateway.conf on nodes where you have installed the Data Access Gateway. Modify the following settings to control the amount of memory allocated to the service:

Parameter Default Description
service.heapsize.max 3000 Defines the maximum heap size (in MB) for the service
service.heapsize.min 3000 Defines the minimum heap size (in MB) for the service

After modifying the warden configuration file on a node, run configure.sh -R, and restart the service:

/opt/mapr/server/configure.sh -R
maprcli node services -nodes <node name> -name data-access-gateway -action restart

Administering the Data Access Gateway Service

The MapR Data Access Gateway is a service that you administer in the same way as other MapR services. The name of the service is data-access-gateway.

To restart the service through the CLI, run the following command:
maprcli node services -nodes <node name> -name data-access-gateway -action restart

See Managing Services for details about other operations you can perform on the service.