CockroachDB MCP Server

Instructions

Args:
    active_only: Only show sessions with active queries.

Returns:
    List of sessions.

Implementation Reference

• src/cockroachdb_mcp/server.py:486-499 (handler)

  MCP tool handler for 'show_sessions'. Registered with @mcp.tool() decorator and delegates execution to the cluster helper function.

  @mcp.tool()
  async def show_sessions(active_only: bool = True) -> dict[str, Any]:
      """Show active sessions in the cluster.
  
      Args:
          active_only: Only show sessions with active queries.
  
      Returns:
          List of sessions.
      """
      try:
          return await cluster.show_sessions(active_only)
      except Exception as e:
          return {"status": "error", "error": str(e)}

• src/cockroachdb_mcp/tools/cluster.py:289-338 (helper)

  Underlying helper function that executes the SQL query against crdb_internal.cluster_sessions to retrieve and format session information.

  async def show_sessions(active_only: bool = True) -> dict[str, Any]:
      """Show active sessions in the cluster.
  
      Args:
          active_only: Only show active sessions.
  
      Returns:
          List of sessions.
      """
      conn = await connection_manager.ensure_connected()
  
      try:
          query = """
              SELECT
                  session_id,
                  node_id,
                  user_name,
                  client_address,
                  application_name,
                  active_queries,
                  start
              FROM crdb_internal.cluster_sessions
          """
  
          if active_only:
              query += " WHERE active_queries != '{}'"
  
          query += " ORDER BY start DESC"
  
          async with conn.cursor() as cur:
              await cur.execute(query)
              rows = await cur.fetchall()
  
          sessions = []
          for row in rows:
              sessions.append(
                  {
                      "session_id": row.get("session_id"),
                      "node_id": row.get("node_id"),
                      "user": row.get("user_name"),
                      "client_address": row.get("client_address"),
                      "application": row.get("application_name"),
                      "active_queries": row.get("active_queries"),
                      "started": str(row.get("start")) if row.get("start") else None,
                  }
              )
  
          return {"sessions": sessions, "count": len(sessions)}
      except Exception as e:
          return {"status": "error", "error": str(e)}