FAQ

There are two offerings: Free Edition and Enterprise Edition. Each offering is described below.

AnzoGraph DB Free Edition

AnzoGraph DB Free Edition has two variations:

• By default, all deployments include an embedded Free Edition (8 GB) license. The license does not expire but is limited to operation on a single server. In addition, AnzoGraph DB is limited to a maximum of 8 GB RAM and maximum utilization of up to 8 CPU cores. This means the host server can have a large amount of available memory, but AnzoGraph DB will not allocate over 8 GB or use more than 8 CPU cores for data and queries. You do not have to register with Cambridge Semantics to use the 8 GB Free Edition version.

  The restrictions for this version are outlined in the AnzoGraph End User License Agreement.

• You can increase the memory limit to 16 GB for the Free Edition version by registering with Cambridge Semantics and generating a new Free Edition (16 GB RAM limit) license key. This license is also limited to operation on a single server, and AnzoGraph DB will not use more than 16 GB RAM or 16 CPU cores for data and queries.

AnzoGraph DB Enterprise Edition

The free AnzoGraph DB Enterprise Edition is available for users who want to test AnzoGraph DB scale and performance. This edition does not place any limitations on RAM or the number of servers you can deploy in an AnzoGraph DB cluster. You must register with Cambridge Semantics to generate an Enterprise Edition license, and the license expires after 60 days.

By default, all AnzoGraph DB deployments include an embedded Free Edition (8 GB) license. This license can be used anonymously, i.e., you do not need to register with Cambridge Semantics. Simply deploy AnzoGraph DB and start using it. The anonymous free license does not expire, but it is limited to single-server usage, and, regardless of the size of the host server, AnzoGraph DB will not use more than 8 GB RAM.

When you are ready to increase the memory usage limit or remove limits altogether (with the Enterprise Edition), you can upgrade your license for free by registering with Cambridge Semantics and generating a new license key. See Upgrading a License for instructions.

For more information about registering, see the AnzoGraph DB Download page.

If you have the AnzoGraph DB front end installed, upgrade your license from the AnzoGraph DB Admin console. For instructions, see Upgrading a License from the User Interface. If you do not have the front end installed, upgrade your license using the command line. For instructions, see Upgrading a License from the Command Line.

To offer versatility for different types of environments and deployment preferences, Cambridge Semantics provides three AnzoGraph DB container images. The list below describes each image and its purpose:

• anzograph (all-in-one image): The all-in-one image (https://hub.docker.com/r/cambridgesemantics/anzograph) includes the front end (user interface) as well the back end (database) in one image.
• anzograph-frontend (user interface): The front end image (https://hub.docker.com/r/cambridgesemantics/anzograph-frontend) includes the user interface only. Multiple users can deploy the front end locally and use it to access a central AnzoGraph DB database cluster.
• anzograph-db (back end/database): The back end image (https://hub.docker.com/r/cambridgesemantics/anzograph-db) includes the database only. If you have existing client applications to use with AnzoGraph DB and do not need the front end, you can deploy the database by itself.

For guidance on determining the number of instances to include in your cluster and choosing the most suitable instance type, see the best practice Sizing Guidelines for In-Memory Storage.

For best practices and in-depth information about benchmarking with AnzoGraph DB, see the AnzoGraph DB Benchmarking Guide.

AnzoGraph DB supports the standard W3C SPARQL 1.1 Protocol (SPARQL endpoint) and SPARQL 1.1 Graph Store HTTP Protocol (RDF Graph Store endpoint). The SPARQL endpoint and Graph Store endpoint are both enabled by default. And both endpoints can be accessed through the front end (user interface) or the back end (database).

• If you have the front end client deployed, the endpoints are enabled and can be accessed by applications that have access to the front end server. User authentication is required to access endpoints through the front end.
• Back end endpoints are also enabled by default but are controlled by the enable_sparql_protocol configuration setting. If SPARQL protocol is disabled for your deployment, the database endpoints will not be accessible. See How do I enable SPARQL HTTP protocol? for instructions on enabling SPARQL protocol. The back end endpoints do not support user authentication at this time.

For more information about the endpoints, see Accessing the SPARQL and RDF Endpoints.

AnzoGraph DB endpoints conform to the W3C SPARQL 1.1 standards and can be accessed like other standard SPARQL endpoints. For usage information and details about the AnzoGraph DB endpoints, see Accessing the SPARQL and RDF Endpoints.

For W3C specifications on SPARQL endpoints, see SPARQL 1.1 Protocol. For RDF graph store specifications, see SPARQL 1.1 Graph Store HTTP Protocol.

If HTTP protocol is disabled for your deployment and you want to enable it so that you can use the AnzoGraph DB CLI or post queries to the SPARQL HTTP port (7070 by default), follow the instructions below.

1. Stop AnzoGraph DB. You can stop the database from the Admin user interface, or see Starting and Stopping AnzoGraph DB for information about alternate methods.
2. Open the AnzoGraph DB settings file /install_path/config/settings.conf in an editor.

   How do I access the AnzoGraph DB file system with Docker? For example:

   vi /opt/anzograph/config/settings.conf

3. Find the enable_sparql_protocol setting. If the setting is listed, change the value from "false" to true. If the setting is not listed, add a new line to the end of the file and enter the following value:

   enable_sparql_protocol=true

4. Save and close the file, and then restart AnzoGraph DB.

Once AnzoGraph DB starts, SPARQL HTTP protocol is enabled on the sparql_protocol_port (7070 by default) and you can use the CLI (AZGI) or send requests through the back end (database) SPARQL endpoints. For more information about AnzoGraph DB endpoints, see Accessing the SPARQL and RDF Endpoints.

To reset the AnzoGraph DB admin password, SSH to the AnzoGraph DB host server (the leader node if this is a cluster) and run the following command. This command runs the azgpasswd utility in the anzograph/bin directory and updates the password (passwd) file in the anzograph/config directory:

./<install_path>/bin/azgpasswd /<install_path>/config/passwd -u admin -p <password>

For example, the following command resets the password to "Passw0rd1":

./opt/csi/anzograph/bin/azgpasswd /opt/csi/anzograph/config/passwd -u admin -p Passw0rd1

Run the following Docker command to access the AnzoGraph DB file system, the /opt/anzograph directory:

sudo docker exec -it <container_name> /bin/bash

Where <container_name> is the name of the AnzoGraph DB container whose file system you want to access. For example:

sudo docker exec -it anzograph /bin/bash

1. Run the following Docker command to access the AnzoGraph DB file system, the /opt/anzograph directory:

   sudo docker exec -it <container_name> /bin/bash

   Where <container_name> is the name of the AnzoGraph DB container whose file system you want to access. For example:

   sudo docker exec -it anzograph /bin/bash

2. Determine where on the file system you would like to place the load files and create a new directory if necessary. If you plan to load a directory of files, remember to include the file type in the directory name. See RDF Load File Requirements for more information. For example:

   mkdir /opt/anzograph/load-files.ttl

3. Type exit to exit the container.
4. Run the following Docker command to copy files from the host server to a location in the AnzoGraph DB container.

   sudo docker cp /<path>/<filename> <container_name>:/<path>/<directory>

   For example:

   sudo docker cp /home/user/sales.ttl anzograph:/opt/anzograph/load-files.ttl/

   Or this command copies a directory to the container:

   sudo docker cp -r /<path>/<directory> <container_name>:/<path>

   For example:

   sudo docker cp -r /home/user/load-files.ttl anzograph:/opt/anzograph/

To customize a Helm-managed deployment, modify the AnzoGraph DB Helm chart, values.yaml, and then deploy AnzoGraph DB using that chart.

• The values.yaml file is in the HELM_HOME directory. To view the location of HELM_HOME, you can run helm home.
• To download the latest version of the Helm chart from csi-helm/anzograph, you can run helm repo update.
• You can edit values.yaml directly or make a copy and edit the copy. When you run the helm install command to deploy AnzoGraph DB, specify the name of the Helm chart to use for that deployment.
• For details about the Helm chart options, view the readme, Readme.md, in the HELM_HOME directory.

For instructions on deploying AnzoGraph DB with Helm, see Deploying AnzoGraph DB with Helm.

For most installations AnzoGraph DB is configured by default to save the data in memory to disk after every transaction. Each time AnzoGraph DB is restarted, the persisted data is automatically loaded back into memory. To check whether the save to disk option is enabled, open the settings file, install_path/config/settings.conf, and find the enable_persistence option. If enable_persistence=true, data persistence is enabled. If enable_persistence=false, persistence is disabled. For instructions on changing settings, see Changing System Settings.

Important Considerations

• In general, each AnzoGraph DB server needs access to about twice as much disk space as RAM on the server. By default, AnzoGraph DB saves data to the install_path/persistence directory on the local file system. You can also configure AnzoGraph DB to save data to a different location by changing the value of the persistence_directory setting in settings.conf.
• When persistence is enabled, transactional workloads that perform many concurrent write operations may experience a performance degradation due to the overhead of writing the data from each transaction to disk.

  For AWS CFN deployments, you are prompted to enable or disable persistence at deployment time. See Do I need to reload my data if I stop AnzoGraph DB or restart the AWS instances? for more information.

• Turtle (.ttl file type): Terse RDF Triple Language that writes an RDF graph in compact form.
• N-Triple (.n3 and .nt file types): A subset of Turtle known as simple triples.
• N-Quad (.nq and .quads file types): N-Triples with a blank node or graph designation.
• TriG (.trig file type): An extension of Turtle that supports representing a complete RDF data set.
• JSON-LD (.jsonld file type): A method of encoding linked data using JSON. JSON-LD files are supported for loading via the IO services. JSON-LD is not supported by SPARQL LOAD queries.

For more information, see Loading RDF Data from Files.

When you have multiple files, AnzoGraph DB loads the files in parallel, using all available cores on all servers in the cluster. While you can load files stored on the leader node's local file system, for optimal performance, it is important to use a shared file system to ensure that all servers in the cluster have access to the files. In a Docker or Kubernetes container environment, the storage system should also be shared with the container file system.

For more information and details about load file requirements, see RDF Load File Requirements.

You can run the following query to return a list of supported SPARQL functions. The query returns all of the function names as well as the supported argument and return types for each function:

SELECT ?extension_name ?extension_arguments ?extension_results
WHERE { TABLE 'stc_functions'}
ORDER BY ?extension_name

1. Log in to the AWS VPC Management Console. In the VPC Management Console navigation, click Subnets. The console displays the list of subnets.
2. In the search field above the list, search for the VPC that contains the subnet whose ID you need. The console displays the subnets for that VPC.
3. Click the check box next to the subnet to display the subnet details, and then copy the Subnet ID value.

For security reasons, the AnzoGraph DB CloudFormation service does not automatically enable secure shell access to AnzoGraph DB instances. If you want to enable SSH access to a cluster, follow the instructions below.

1. Log in to the AWS CloudFormation Management Console. AWS opens the CloudFormation Stacks page where you can view a list of your stacks.
2. In the list of stacks, click the stack name for the stack to which you want to enable SSH access. AWS displays the Stack Detail screen for that stack.
3. On the Stack Detail screen, expand the Outputs section, and then click the URL for NetworkSecurityGroup. For example:

   

   AWS displays the Security Group screen.

4. On the Security Group screen, your security group is selected and the details for the security group are shown at the bottom of the screen. For example:

   

5. Click the Actions button at the top of the screen, and select Edit Inbound Rules. The Edit inbound rules screen is displayed. For example:

   

6. At the bottom of the screen, click Add rule. AWS adds a new rule row to the end of the table.
7. In the new row, click the Custom TCP Rule drop-down list and select SSH (22).
8. In the Source field for the rule, type the CIDR that should have SSH access to the AnzoGraph DB instances. For example, to enable SSH access for the same CIDR that has HTTPS access to AnzoGraph DB, you can copy the CIDR from the Source field for the HTTPS (443) rule. If you want to enable SSH access for multiple CIDRs, create an additional SSH (22) rule for each CIDR.
9. When you are finished adding rules, click the Save rules button at the bottom of the screen.

The security group is now configured to allow SSH access to any AnzoGraph DB instances that belong to the security group. You can SSH to an instance using the EC2 key pair that you specified when you deployed the stack. For information about connecting to EC2 instances, see Connect to Your Linux Instance in the AWS Documentation.

The Persist data to disk option in the CloudFormation wizard defaults to yes for AnzoGraph DB deployments. The option enables persistence, and the data in memory is saved to disk. AnzoGraph DB automatically loads the data on disk into memory any time AnzoGraph DB is restarted. If the Persist data to disk option is disabled during the deployment, AnzoGraph DB does not save data to disk and the data in memory must be reloaded manually any time AnzoGraph DB is restarted.

1. Log in to the AWS CloudFormation Management Console. AWS opens the CloudFormation Stacks page where you can view a list of your stacks.
2. In the list of stacks, select the radio button next to the stack that you want to delete. Then click the Delete button.

   The console displays a Delete Stack confirmation message. Click Delete stack to delete the stack. The status of the stack changes to DELETE_IN_PROGRESS and the CloudFormation service removes AnzoGraph DB and its supporting infrastructure.

For more information about managing stacks, see Managing AWS CloudFormation Stacks.

For instructions on finding the ID or alias for your AWS account, see Your AWS Account ID and Its Alias in the AWS Documentation.

When deploying AnzoGraph DB on AWS with the Cambridge Semantics CloudFormation Service, you can choose from various Memory Optimized R4 and R5 type instances for the deployment. Both types are optimized for in-memory databases like AnzoGraph DB where you might load large amounts of data and run advanced analytics. These types have much higher network bandwidth than M4 or M5 types, which is optimal for clustered environments. And they provide more memory per CPU than the general purpose instances.

For specifics about the EC2 types, see Memory Optimized types in the AWS documentation.

AnzoGraph DB extends the W3C SPARQL 1.1 specifications to add support for advanced analytics features such as window aggregates, subquery factoring, generating inferences, graph algorithms, and creating views. For more information, see AnzoGraph DB SPARQL Extensions.

For basic information about SPARQL, the semantic web, or RDF, see the Cambridge Semantics Semantic University. In addition, the Semantic Web for the Working Ontologist focuses on SPARQL and RDF usage using Internet examples.

To view the W3C formal specification and definitive reference, see the SPARQL 1.1 Query Language specification.

For additional information about best practices and tips, see SPARQL Best Practices and SPARQL Tips and Tricks.