Doc 13539 data disk storage sizing info #4022
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| S_{\mathrm{keys}} = 1,000,000 \times 32 = 32,000,000 \text{bytes} | ||
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| . Calculate the tombstone space: |
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My calculator doesn't agree with the result in the document for the tombstone space.
This is what I get: 32+60=92, so
92 x 3 x 2 x 5000 = 2,760,000
This is what's in the document.
Calculate the tombstone space:
𝑆tombstones=(32+60)×3×(1+1)×5,000=920,000bytes
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| . Calculate the total disk space required using the following formula: |
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The formula is not correct.
The tombstones size -- theS<tombstones>-- is not multiplied by the append-only multiplier.
The formula is:
Data storage needed = Tombstone space + ((A + B + C + D) * multiplier)
(Apologies that it wasn't clear -- I've clarified in my document.)
So, the formula in the document should be:
- Calculate the total disk space required using the following formula:
Instead of:
total disk space=((𝑆dataset×(# replicas+1)+𝑆metadata+𝑆keys+𝑆tombstones)×𝐹append-multiplier)
Should be:
total disk space=((𝑆dataset×(# replicas+1)+𝑆metadata+𝑆keys)×𝐹append-multiplier) + 𝑆tombstones
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| Therefore, for the cluster in this example, you need at least 15.35{nbsp}GB of disk space to store your data. |
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Using these values and the correct formula:
𝑆tombstones=2,760,000
𝑆dataset=1,000,000×10,000×0.7=7,000,000,000bytes
𝑆metadata=1,000,000×56=56,000,000bytes
𝑆keys=1,000,000×32=32,000,000bytes
((7,000,000,000 + 7,000,000,000 + 56,000,000 + 32,000,000) x 2.2) + 2,760,000 = 30,996,360,000
About 31 GB.
hyunjuV
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hyunjuV
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- The S shouldn't be multiplied by the append-only multiplier. The formula was not clear in my document -- I've clarified.
- The S calculation doesn't seem correct -- the input values are OK, but the calculated value doesn't match what I got on my calculator.
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Hi @hyunjuV, thanks for spotting the errors. I believe I've corrected them and updated the preview. |
This PR addresses DOC-13539, which requests adding disk sizing information the Sizing Guidelines page. The changes were all made under the Sizing Data Service Nodes heading. I split out the RAM guidelines into its own subheading and added a Disk Sizing for Data Service Nodes subheading with the new content.
The preview is here:
https://preview.docs-test.couchbase.com/docs-server-DOC-13539_data_disk_storage_sizing_info/server/current/install/sizing-general.html#sizing-data-service-nodes
You will need the Docs Team credentials on Confluence.