Forum Discussion

MaxMedov's avatar
MaxMedov
Icon for Cirrostratus rankCirrostratus
Sep 12, 2023
Solved

Number of DCDs

Hello, I saw in a few F5 docs that installing three DCDs instead of one or two is more recommended. I understood the benefit of two DCDs due to the redundancy of replicas, but why is it recommended ...
  • Nikoolayy1's avatar
    Sep 13, 2023

    If you have 3 DCD then the shard mirroring between the DCD will be like 30%. How to explain imagine that DCD 1 goes down then to restore the missing statistics data DCD 2 and DCD 3 will use their own information, so when you have 3 DCD it is not like each one having the exact same copy of the other 2 and it is more opimized.

     

    It is like RAID 1 when you have 2 DCD and RAID 5 when you have 3 DCD:

    https://en.wikipedia.org/wiki/RAID