Please explain how Redis usedmemorypercentage is calculated? After reviewing the Azure documentation, we did not find any introduction to its calculation method. Please help explain, thank you.

Hi Gallatin 21V - Thanks for reaching out. We use effective memory to calculate UsedMemoryPercentage . By effective memory, it means the memory used for storing keys, subtracting the memory for replication between nodes, memory reserved. Finally, UsedMemoryPercentage = (UsedMemory - BacklogSizeforReplication) / ( Maxmemory - MaxMemoryReserved - MaxFragmentationMemoryReserved - BacklogSizeforReplication) Are you observing any issues with the same? Please let us know if you have any further queries. I’m happy to assist you further. Please "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.

How is the Redis usedmemorypercentage calculated?

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Amrinder Singh 5,155 Reputation points Microsoft Employee

2024-05-27T06:32:35.4766667+00:00

Hi Gallatin 21V - Thanks for reaching out.

We use effective memory to calculate UsedMemoryPercentage. By effective memory, it means the memory used for storing keys, subtracting the memory for replication between nodes, memory reserved. Finally,

UsedMemoryPercentage = (UsedMemory - BacklogSizeforReplication) / ( Maxmemory - MaxMemoryReserved - MaxFragmentationMemoryReserved - BacklogSizeforReplication)

Are you observing any issues with the same? Please let us know if you have any further queries. I’m happy to assist you further.

Please "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.
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Gallatin 21V 186 Reputation points

2024-05-27T06:48:42.83+00:00

Thanks Singh,BacklogSizeforReplication、MaxFragmentationMemoryReserved、BacklogSizeforReplication I haven't seen these Azure chiina redis indicators, where can I get them?

Amrinder Singh 5,155 Reputation points Microsoft Employee

2024-05-27T14:34:06.4266667+00:00

Hi Gallatin 21V-

BacklogSizeforReplication - This is calculated internally and shouldn't have much of affect. You can consider it to be minimal though for rough calculations.

MaxFragmentationMemoryReserved - I believe this shall be under the advance settings as discussed in the below link:

https://learn.microsoft.com/en-us/azure/azure-cache-for-redis/cache-configure?tabs=access-keys#memory-policies

Hope that helps!

Gallatin 21V 186 Reputation points

2024-05-28T07:06:21.4766667+00:00

Hi Singn,

I calculated that the value of UsedMemoryPercentage is not 5% based on the calculation method you mentioned. I have a question: I am not sure about the size of the BacklogSizeforreplication parameter, so I did not include it in the formula. Please help me check. I used 135.1MB, why is UsedMemoryPercentage 5%?

Thank you very much. 😊

Gallatin 21V 186 Reputation points

2024-05-30T09:34:05.5433333+00:00

Hi Singn,

Is there anything you need to tell us? expect to your reply.

Thanks.

Gallatin 21V 186 Reputation points

2024-05-30T09:36:18.37+00:00

Sorry.Due to slow UI refresh, please refer to the previous cover.

Amrinder Singh 5,155 Reputation points Microsoft Employee

2024-05-30T19:37:14.0766667+00:00

Hi Gallatin 21V - Sorry I missed replying to this one.

UsedMemory - 135 M

BacklogSizeforReplication - 100 M (Default)

Maxmemory - 1100 M

MaxMemoryReserved - 123 M

MaxFragmentationMemoryReserved - 123 M

With above value, it will get to ~4.6 and rounded off to 5%.

Gallatin 21V 186 Reputation points

2024-06-04T09:07:59.2866667+00:00

Hi Singh，

Thank you for your professional answer. I have learned a lot, thank you again.

Amrinder Singh 5,155 Reputation points Microsoft Employee

2024-06-05T07:27:26.0633333+00:00

Hi Gallatin 21V - Thank you and glad to help.

I would request you to please "Accept the answer” and “up-vote” wherever the information provided helps you, this can be beneficial to other community members.
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How is the Redis usedmemorypercentage calculated?

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