--- title: "Server Connection Management" description: "Managing MotherDuck server connections" --- # Server Connection Management Managing MotherDuck server connections ## Included pages - [Monitoring active server connections](https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/monitor-connections): View active connections and running queries in MotherDuck using md_active_connections. - [Interrupting active server connections](https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/interrupt-connections): Cancel running queries and terminate active connections to MotherDuck using SQL commands. - [Identify client connection and DuckDB ID](https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/connection-duckdb-id): Retrieve connection identifiers and DuckDB instance IDs for debugging and monitoring. - [Retrieve the last query ID](https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/last-query-id): Use MD_LAST_QUERY_ID() to get the UUID of the most recent query sent to MotherDuck. Source: https://motherduck.com/docs/category/server-connection-management --- ## Monitoring active server connections Source: https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/monitor-connections > View active connections and running queries in MotherDuck using md_active_connections. :::info This is a preview feature. Preview features may be operationally incomplete and may offer limited backward compatibility. ::: # Monitoring active server connections :::tip You can also monitor running queries in the MotherDuck UI under **Settings** → **Running Queries**. See [Running Queries](/getting-started/interfaces/motherduck-quick-tour/#running-queries) for details. For an org-wide view of running and recently completed queries, see the [`RECENT_QUERIES`](/sql-reference/motherduck-sql-reference/md_information_schema/recent_queries/) view (for admins on the Business plan). ::: The `md_active_server_connections` table function can be used to list all server-side connections that have active transactions. ## Syntax ```sql FROM md_active_server_connections(); ``` This returns a list of active server connections, with the following information: | **column_name** | **column_type** | **description** | |-------------------------------------|-----------------|----------------------------------------------------------------------------------| | client_duckdb_id | UUID | Unique identifier for the client DuckDB instance that initiated the connection | | client_user_agent | VARCHAR | User agent for the client | | client_duckdb_version | USMALLINT[3] | DuckDB version from the client | | client_connection_id | UUID | Unique identifier for the client DuckDB connection that initiated the connection | | client_transaction_id | UBIGINT | Identifier for the transaction within the current connection | | server_transaction_stage | VARCHAR | Stage the server-side transaction is in | | server_transaction_elapsed_time | INTERVAL | How long the server-side transaction has been in the current stage | | client_query_id | UBIGINT | Identifier for the query within the current transaction | | client_query | VARCHAR | Query string (possibly truncated) | | server_query_elapsed_time | INTERVAL | How long the query has been running on the server-side | | server_query_execution_elapsed_time | INTERVAL | How long the connection has been interrupted | | server_query_progress | DOUBLE | Progress information (value between 0.0 and 1.0) | | server_interrupt_elapsed_time | INTERVAL | How long the connection has been interrupted | | server_interrupt_reason | VARCHAR | Why the connection was interrupted | | query_total_upload_size | UBIGINT | Data uploaded in Bytes | | query_total_download_size | UBIGINT | Data downloaded in Bytes | --- ## Interrupting active server connections Source: https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/interrupt-connections > Cancel running queries and terminate active connections to MotherDuck using SQL commands. :::info This is a preview feature. Preview features may be operationally incomplete and may offer limited backward compatibility. ::: # Interrupting active server connections :::tip You can also cancel running queries in the MotherDuck UI under **Settings** → **Running Queries**. See [Running Queries](/getting-started/interfaces/motherduck-quick-tour/#running-queries) for details. To identify long-running queries across your organization, see the [`RECENT_QUERIES`](/sql-reference/motherduck-sql-reference/md_information_schema/recent_queries/) view (for admins on the Business plan). ::: The `md_interrupt_server_connection` scalar function can be used to interrupt an active transaction on a server-side connection. This will interrupt and fail / rollback the active transaction (when executing for example a long-running query), but will allow the connection to be used for future transactions and queries. The function takes as input the `client_connection_id`, i.e. the unique identifier for the client DuckDB connection that initiated the server connection. ## Syntax ```sql SELECT md_interrupt_server_connection(); ``` ## Return value Returns a `BOOLEAN`: - `true` — the interrupt signal was successfully sent to the connection - `false` — the interrupt could not be sent, which can happen if: the connection is already closed, the transaction is committing or rolling back, or the server-side connection could not be found ## Example usage Interrupting a specific connection: ```sql SELECT md_interrupt_server_connection('2601e799-51b3-47a7-a64f-18688d148887'); ``` Using `md_interrupt_server_connection` in conjunction with [`md_active_server_connections`](documentation/sql-reference/motherduck-sql-reference/connection-management/monitor-connections.md) to interrupt a subset or all of the currently active connections: ```sql -- Interrupt all connections where a `CREATE TABLE` query is running SELECT md_interrupt_server_connection(client_connection_id) FROM md_active_server_connections() WHERE client_query ILIKE 'CREATE TABLE%'; ``` The query returns one boolean per matched connection indicating whether each interrupt succeeded. If 0 rows are returned, no active connections matched the filter — the query may have already finished. --- ## Identify client connection and DuckDB ID Source: https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/connection-duckdb-id > Retrieve connection identifiers and DuckDB instance IDs for debugging and monitoring. :::info This is a preview feature. Preview features may be operationally incomplete and may offer limited backward compatibility. ::: # Identify client connection and DuckDB ID `md_current_client_connection_id` and `md_current_client_duckdb_id` are two scalar functions that can be used to identify the current `client_connection_id` and `client_duckdb_id`. ## Syntax ```sql SELECT md_current_client_connection_id(); SELECT md_current_client_duckdb_id(); ``` ## Example usage To [interrupt](documentation/sql-reference/motherduck-sql-reference/connection-management/interrupt-connections.md) all server-side connections that are initiated by the current client DuckDB instance, we can use: ```sql SELECT md_interrupt_server_connection(client_connection_id) FROM md_active_server_connections() WHERE client_duckdb_id = md_current_client_duckdb_id() AND client_connection_id != md_current_client_connection_id(); ``` --- ## Retrieve the last query ID Source: https://motherduck.com/docs/sql-reference/motherduck-sql-reference/connection-management/last-query-id > Use MD_LAST_QUERY_ID() to get the UUID of the most recent query sent to MotherDuck. # Retrieve the last query ID `MD_LAST_QUERY_ID()` is a scalar function that returns the UUID of the most recent query sent to the MotherDuck server from the current DuckDB [connection](/key-tasks/authenticating-and-connecting-to-motherduck/connecting-to-motherduck/#create-a-connection). This is the same `QUERY_ID` that appears in the [`QUERY_HISTORY`](../md_information_schema/query_history.md) and [`RECENT_QUERIES`](../md_information_schema/recent_queries.md) views. The function returns `NULL` if no query has been sent to the server yet on the current connection. ## Syntax ```sql SELECT MD_LAST_QUERY_ID(); ``` ## Return type `UUID`: the unique identifier of the last query, or `NULL` if no server-side query has been run. ## Example usage ### Get the ID of your last query ```sql SELECT MD_LAST_QUERY_ID(); ``` ### Look up details for last query from this connection in the query history ```sql SELECT * FROM MD_INFORMATION_SCHEMA.QUERY_HISTORY WHERE QUERY_ID = MD_LAST_QUERY_ID(); ``` ---