Enabling AnzoGraph Persistence

By default, Anzo manages the data in AnzoGraph by automatically reloading graphmart data into memory any time you restart AnzoGraph. Users have the option, however, to enable AnzoGraph's save data to disk option where AnzoGraph saves the data in memory to disk after every transaction. Each time AnzoGraph is restarted, the persisted data is automatically loaded back into memory.

This topic provides instructions for enabling AnzoGraph persistence.

Important Considerations

Before enabling persistence, consider the following important notes:

  • In general, each AnzoGraph server needs access to about twice as much disk space as RAM on the server. By default, AnzoGraph saves data to the AnzoGraph_root_dir/persistence directory on the local file system. You can also configure AnzoGraph to save data to a mounted file system. For more information, see Relocating AnzoGraph Directories.
  • 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.

Enabling Persistence

Follow the steps below to enable the AnzoGraph save to disk option.

  1. Stop the database by running the following command on the leader node: 
    ./installation_path/AnzoGraph_root_dir/bin/azgctl -stop
  2. Open the AnzoGraph settings file, settings.conf, in a text editor. The file is in the AnzoGraph_root_dir/config directory.
  3. In settings.conf, find the following line in the file:
    enable_persistence=false
  4. Change the enable_persistence value to true:
    enable_persistence=true
  5. Save and close settings.conf.
  6. Restart the database by running the following command: 
    ./installation_path/AnzoGraph_root_dir/bin/azgctl -start

After each transaction, AnzoGraph saves the data in memory to disk in the location specified in the persistence_directory setting.

Note: To avoid unnecessary reloads, make sure that the AnzoGraph connection in Anzo is configured to enable the Use AnzoGraph persistence if available option. See Configuring an AnzoGraph Connection for more information.

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