code: public int getActiveConnections(String dbPoolUrl) throws CmsDbException {
  
          CmsDbPoolV11 pool = m_pools.get(dbPoolUrl);
          if (pool == null) {
              CmsMessageContainer message = Messages.get().container(Messages.ERR_UNKNOWN_POOL_URL_1, dbPoolUrl);
              throw new CmsDbException(message);
          }
          try {
              return pool.getActiveConnections();
          } catch (Exception exc) {
              CmsMessageContainer message = Messages.get().container(Messages.ERR_ACCESSING_POOL_1, dbPoolUrl);
              throw new CmsDbException(message, exc);
          }
  
      }
docs: Returns the number of active connections managed by a pool.<p>
  
  @param dbPoolUrl the url of a pool
  @return the number of active connections
  @throws CmsDbException if something goes wrong