HDF5 supports multiple readers already, and with HDF5-1.10, the SWMR (Single Writer Multiple Reader) feature was also introduced.

Once you set your HDF5 to SWMR however, you can never turn it off again. That means, you can never add a new dataset (only extending existing ones):

  
      github.com/h5py/h5py
  
  
    
  
	  
  

  
    
      SWMR cannot be turned off once set to True; Allow forceful switching off 15
    

    
      
        opened 
        
          
        
        Dec 5, 2019
      
      


      
        
          
          NumesSanguis
        
      
    
  



  Operating System: import h5py; print(h5py.version.info)
Python version: 3.7.5 (default, Oct 25 2019, 15:51:11)
Where Python was acquired: Miniconda3
h5py version: 2.10.0
HDF5 version: 1.10.5
numpy: 1.17.3
When...