Migrating an Enterprise Database to Eon Mode

Vertica meta-function MIGRATE_ENTERPRISE_TO_EON migrates an Enterprise database to Eon Mode. The migration process includes the following stages:

  1. Check migration prerequisites
  2. Verify compliance
  3. Execute the migration
  4. Check migration results
  5. Activate the Eon database

Migration Prerequisites

The following conditions must be true; otherwise, MIGRATE_ENTERPRISE_TO_EON returns with an error:

  • The source Enterprise database version must be ≥10.0.
  • All nodes in the source database must be in an UP state and of type PERMANENT or EPHEMERAL. Verify by querying system table NODES:
    => SELECT node_name, node_type, node_state FROM nodes;
        node_name     | node_type | node_state
     v_vmart_node0001 | PERMANENT | UP
     v_vmart_node0002 | PERMANENT | UP
     v_vmart_node0003 | PERMANENT | UP
    (3 rows)

    When planning how to provision the target Eon database, consider that MIGRATE_ENTERPRISE_TO_EON creates the same number of nodes as on the original Enterprise database , and an equal number of segmented shards. Choose the appropriate instance type accordingly.

  • The source database must be configured as an elastic cluster. By default, any database created since Vertica release 9.2.1 is configured as an elastic cluster. To verify whether an Enterprise database is configured as an elastic cluster, query system table ELASTIC_CLUSTER:
    => SELECT is_enabled FROM elastic_cluster;
    (1 row)

    If the query returns false, call meta-function ENABLE_ELASTIC_CLUSTER on the Enterprise database.

  • The source Enterprise database must configure Eon parameters as required by the target Eon object store (see Configuration Requirements below).
  • The database must not contain projections that are unsupported by Eon.

Unsupported Projections

Eon databases do not support four types of projections, as described below. If MIGRATE_ENTERPRISE_TO_EON finds any of these projection types in the Enterprise database, it rolls back the migration and reports the offending projections or their anchor tables in the migration error log. For example:

The following projections are inconsistent with cluster segmentation. Rebalance them with REBALANCE_CLUSTER() or REBALANCE_TABLE():
Projection(Anchor Table): public.incon1_p1_b0(public.incon1)
Why projection is invalid Notes Resolution

Inconsistent with cluster segmentation.

For example, nodes were added to the cluster, so current distribution of projection data is inconsistent with new cluster segmentation requirements.

Rebalance cluster or table.

The error log file lists the names of all tables with problematic projections. You can use these names as arguments to meta-function REBALANCE_TABLE. You can also rebalance all projections by calling REBALANCE_CLUSTER.

Does not support elastic segmentation.

Projection was created with the NODES option, or in a database where elastic segmentation was disabled. Drop projection, recreate with ALL NODES.
Defined with a GROUPED clause. Consolidates multiple columns in a single ROS container. Drop projection, recreate without GROUPED clause.
Data stored in unbundled storage containers.

Found only in Vertica databases that were created before storage container bundling was introduced in version 7.2.

Bundle storage containers in database with meta-function COMPACT_STORAGE.

The error log names all tables with projections that store data in unbundled storage containers. You can use these names as arguments to meta-function COMPACT_STORAGE.

Configuration Requirements

Before migration, set the following configuration parameters on the source database.

All parameters must be set at the database level.

Target Eon environment Configuration requirements
S3: AWS, Pure Storage, MinIO

The following requirements apply to all supported cloud and non-cloud (on-premises) environments: AWS, Pure Storage, and MinIO. One exception applies: migration from an Enterprise Mode database on AWS.

If migrating to on-premises communal storage with Pure Storage and MinIO, set configuration parameter AWSEnableHttps to be compatible with the database TLS encryption setup: AWSEnableHttps=1 if using TLS, otherwise 0. If settings are incompatible, the migration returns with an error.

  • You must use an azb:// schema URI to set the Azure Blob Storage location for communal data storage. See Azure Blob Storage Object Store for the format of this URI.
  • Select one of the following authentication methods to grant Vertica access to the storage location:
    • Configure managed identities to grant your Azure VMs access to the storage location. This option does not require any configuration within Vertica.
    • Set the AzureStorageCredentials and AzureStorageEndpointConfig configuration parameters at the database level to have Vertica authenticate with the storage location.

See Azure Blob Storage Object Store for more about the two authentication methods.

HDFS The following requirements apply:

Compliance Verification

Before running migration, check whether the Enterprise source database complies with all migration requirements. You do so by setting the last Boolean argument of MIGRATE_ENTERPRISE_TO_EON to true. This optional argument—by default set to false—specifies whether the meta-function only performs a compliance check. For example:

=> SELECT migrate_enterprise_to_eon('s3://verticadbbucket', '/vertica/depot', true);

If the meta-function discovers any compliance issues, it writes these to the migration error log migrate_enterprise_to_eon_error.log in the database directory.

Migration Execution

MIGRATE_ENTERPRISE_TO_EON migrates an Enterprise database to an Eon Mode database. For example:

=> SELECT migrate_enterprise_to_eon('s3://verticadbbucket', '/vertica/depot', false);

If the meta-function's last Boolean argument is omitted or set to false, it executes the migration. MIGRATE_ENTERPRISE_TO_EON runs in the foreground, and until it returns—either with success or an error—it blocks all operations in the same session on the source Enterprise database. If successful, MIGRATE_ENTERPRISE_TO_EON returns with a list of nodes in the migrated database. You can then proceed to revive the migrated Eon database.

Handling Interrupted Migration

If migration is interrupted before the meta-function returns—for example, the client disconnects, or a network outage occurs—the migration errors out. In this case, call MIGRATE_ENTERPRISE_TO_EON to restart migration.

Communal storage of the target database retains data that was already copied before the error occurred. When you call MIGRATE_ENTERPRISE_TO_EON to resume migration, the meta-function first checks the data on communal storage and only copies unprocessed data from the source database.

When migrating to an Eon database with HDFS communal storage, migration interruptions are liable to leave files in an incomplete state that is visible to users. When you call MIGRATE_ENTERPRISE_TO_EON to resume migration, the meta-function first compares source and target file sizes. If it finds inconsistent sizes for a given file, it truncates the target cluster file and repeats the entire transfer.

Repeating Migration

You can repeat migration multiple times to the same communal storage location. This can be useful for backfilling changes that occurred in the source database during the previous migration.

The following constraints apply:

  • You can migrate from only one database to the same communal storage location.
  • After reviving the newly migrated Eon database, you cannot migrate again to its communal storage, unless you first drop the database and then clean up storage.

Monitoring Migration

System table DATABASE_MIGRATION_STATUS displays the progress of a migration in real time, and also stores data from previous migrations. The following example shows data of a migration that is in progress:

=> SELECT node_name, phase, status, bytes_to_transfer, bytes_transfered, communal_storage_location FROM database_migration_status ORDER BY node_name, start_time;
     node_name    |       phase        |  status   | bytes_to_transfer | bytes_transfered | communal_storage_location        
 v_vmart_node0001 | Catalog Conversion | COMPLETED |                 0 |                0 | s3://verticadbbucket/
 v_vmart_node0001 | Data Transfer      | COMPLETED |              1134 |             1134 | s3://verticadbbucket/
 v_vmart_node0001 | Catalog Transfer   | COMPLETED |              3765 |             3765 | s3://verticadbbucket/
 v_vmart_node0002 | Catalog Conversion | COMPLETED |                 0 |                0 | s3://verticadbbucket/
 v_vmart_node0002 | Data Transfer      | COMPLETED |              1140 |             1140 | s3://verticadbbucket/
 v_vmart_node0002 | Catalog Transfer   | COMPLETED |              3766 |             3766 | s3://verticadbbucket/
 v_vmart_node0003 | Catalog Conversion | COMPLETED |                 0 |                0 | s3://verticadbbucket/
 v_vmart_node0003 | Data Transfer      | RUNNING   |           5272616 |           183955 | s3://verticadbbucket/

Error Logging

MIGRATE_ENTERPRISE_TO_EON logs migration-related warnings, errors, and hints in migrate_enterprise_to_eon_error.log in the database directory. During execution, the meta-function also prints messages to standard output, together with the error log's pathname.

Conversion Results

The following table shows how migration handles visible objects in the source Enterprise database:

From source Enterprise database... To new Eon Mode database...
Global catalog objects Synced to communal storage
Multiple segmented projections in identical buddy projection group One projection in the group
Unsegmented projection replicated on only one node Distributed across all nodes
Number of nodes Same number of nodes, and an equal number of segmented shards
Depot location As specified in MIGRATE_ENTERPRISE_TO_EON. Default depot size is set to 80% of local file system after revive.
USER and TEMP storage locations


Consider evaluating all migrated storage locations for their relevance in an Eon Mode database. For details, see S3 Storage of Temporary Data in Eon Mode.

DATA and TEMP,DATA storage locations

Not migrated. New default DATA and TEMP,DATA storage locations are on the same path as the depot.

Fault groups and storage policies Not migrated
External procedures
Catalog objects related to network settings—load balance groups, network addresses, routing rules, subnets, etc.

Eon Database Activation

After migration is complete and the Eon database is ready for use, perform these steps:

  1. If migrating to an Eon database with HDFS communal storage, create a bootstrapping file to use when you revive the new Eon database. The bootstrapping file must be on the same node where the revive operation is launched, and readable by the user who launches the revive operation.

    A bootstrapping file is required only if the new Eon database uses one or both of the following:

    • High Availability (HA) NameNodes
      Set HadoopConfDir to the location of configuration file hdfs-site.xml—typically, /etc/hadoop/conf. This file defines parameter hdfs.nameservices and individual NameNodes, and must be distributed across all cluster nodes. For details, see Configuring HDFS Access.
    • Kerberos authentication
      Set the following Kerberos configuration parameters:

    For example, the bootstrapping file for an Eon database with HA and Kerberos authentication must have the following settings:

    HadoopConfDir = config-path
    KerberosServiceName = principal-name
    KerberosRealm = realm-name
    KerberosKeytabFile = keytab-path
  2. Revive the database from communal storage on S3 or GCP with Management Console, or with admintools. In the following example, the admintools revive_db command revives a three-node database that uses S3 communal storage:
    admintools -t revive_db 
       -x auth_params.conf \
       --communal-storage-location=s3://verticadbbucket \
       -d VMart \
       -s,, \

    In the next example, revive_db revives an three-node database that uses HDFS communal storage:

    admintools -t revive_db 
       -x bootstrap_params.conf \
      --communal-storage-location=webhdfs://mycluster/verticadb \
      -d verticadb \
      -s vnode01,vnode02,vnode03
  3. Check the controlmode setting in /opt/vertica/config/admintools.conf. This setting must be compatible with the network messaging requirements of your Eon implementation. For example, S3/AWS (Amazon Cloud) relies on unicast messaging, which is compatible with a controlmode setting of point-to-point (pt2pt). If the source database controlmode setting was broacast and you migrate to S3/AWS communal storage, you must change controlmode with admintools:
    $ admintools -t re_ip -d dbname -T

    If controlmode is set incorrectly, attempts to start the migrated Eon database will fail.

  4. Start the Eon Mode database.
  5. Call CLEAN_COMMUNAL_STORAGE to remove unneeded data files that might be left over from the migration.
  6. If migrating to S3 on-premises communal storage—Pure Storage or MinIO—set configuration parameter AWSStreamingConnectionPercentage to 0 with ALTER DATABASE...SET PARAMETER.
  7. Review the depot storage location size and adjust as needed.