prestodb/presto · error · IOException

Metadata for view %s already exists

Error message

Metadata for view %s already exists

What it means

This is the wrapped IOException raised when createViewMetadata detects that a view's metadata znode already exists at viewPath (checkExists != null). The IOException 'Metadata for view %s already exists' is caught by the surrounding handler and rethrown as PrestoException ZOOKEEPER_ERROR ('ZK error when checking if view already exists') with the IOException as cause. It signals CREATE VIEW collision, not a ZK failure.

Source

Thrown at presto-accumulo/src/main/java/com/facebook/presto/accumulo/metadata/ZooKeeperMetadataManager.java:225

    }

    public void deleteTableMetadata(SchemaTableName tableName)
    {
        try {
            curator.delete().deletingChildrenIfNeeded().forPath(getTablePath(tableName));
        }
        catch (Exception e) {
            throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when deleting table metadata", e);
        }
    }

    public void createViewMetadata(AccumuloView view)
    {
        SchemaTableName tableName = view.getSchemaTableName();
        String viewPath = getTablePath(tableName);
        try {
            if (curator.checkExists().forPath(viewPath) != null) {
                throw new IOException(format("Metadata for view %s already exists", tableName));
            }
        }
        catch (Exception e) {
            throw new PrestoException(ZOOKEEPER_ERROR, "ZK error when checking if view already exists", e);
        }

        try {
            curator.create().creatingParentsIfNeeded().forPath(viewPath, toJsonBytes(view));
        }
        catch (Exception e) {
            throw new PrestoException(ZOOKEEPER_ERROR, "Error creating view znode in ZooKeeper", e);
        }
    }

    public void deleteViewMetadata(SchemaTableName tableName)
    {
        try {
            curator.delete().deletingChildrenIfNeeded().forPath(getTablePath(tableName));

View on GitHub (pinned to 55bb57d202)

Solutions

1. Drop the existing view (or its znode) before recreating, or use CREATE OR REPLACE VIEW if supported.
2. Inspect ZooKeeper at the connector metadata root and delete stale view znodes from failed operations.
3. Check for concurrent creators (multiple coordinators) and serialize DDL.
4. Verify table vs view naming collision — the connector uses one path per schema.table.
5. Review the PrestoException's cause: if it contains this IOException, no ZK repair is needed — it's a naming conflict.

Example fix

// before
CREATE VIEW myview AS SELECT ...;
// after
DROP VIEW IF EXISTS myview;
CREATE VIEW myview AS SELECT ...;

// Before CREATE VIEW, check for an existing view
boolean exists = metadata.getView(new SchemaTableName(schema, table)) != null;
if (exists) { drop or replace first }

null

try {
    metadata.createViewMetadata(view);
} catch (PrestoException e) {
    if (e.getCause() instanceof IOException && e.getCause().getMessage().contains("already exists")) {
        throw new PrestoException(ALREADY_EXISTS, "View already exists: " + viewName, e);
    }
    throw e;
}

When it happens

Trigger: Calling createViewMetadata(view) for a SchemaTableName whose znode already exists in ZooKeeper — i.e. a view (or leftover metadata) with the same schema.table was already created. The checkExists succeeds and returns non-null, triggering the IOException.

Common situations: CREATE VIEW on an existing view name without OR REPLACE; leftover znodes from a failed prior create or incomplete cleanup; two coordinators concurrently creating the same view; case-insensitive schema collision.

Related errors

• UNEXPECTED_ACCUMULO_ERROR
• UNEXPECTED_ACCUMULO_ERROR
• NOT_SUPPORTED
• UNEXPECTED_ACCUMULO_ERROR
• ACCUMULO_TABLE_DNE

AI-assisted analysis of prestodb/presto@55bb57d202 (2026-09-04). Data as JSON: /api/errors/1f9cc1fc40173848. Report an issue: GitHub.