# NNS Updates: May 12 - CMC Hotfix **URL:** \ **Category:** Developers\ **Tags:** nns\ **Created:** [May 12, 2023, 10:17pm UTC](https://forum.dfinity.org/t/nns-updates-may-12-cmc-hotfix/19943 "2023-05-12T22:17:03Z")\ **Posts on this page:** 2\ **Page:** 1
**Author:** ![DanielThurau](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/danielthurau/32/3879_2.png) [@DanielThurau](https://forum.dfinity.org/u/DanielThurau)\ **Post date:** [May 12, 2023, 10:17pm UTC](https://forum.dfinity.org/t/nns-updates-may-12-cmc-hotfix/19943/1 "2023-05-12T22:17:03Z")
The DFINITY NNS Team has submitted a proposal to upgrade the CMC Canister on Friday, 2023-05-12. ## Hotfix This hotfix fixes a bug introduced in the last CMC upgrade. Before the last upgrade of the Cycles-Minting Canister, an exchange rate proposal was required to update the ICP/XDR rate as well as the 30-day average ICP/XDR rate (accessible through the endpoints `get_icp_xdr_conversion_rate` and `get_average_icp_xdr_conversion_rate`, respectively). After the upgrade, the CMC started requesting the ICP/XDR rate periodically from the [exchange rate canister](https://forum.dfinity.org/t/new-exchange-rate-mechanism/14543). While the ICP/XDR rate has been updated successfully using this new mechanism ever since the upgrade, a bug prevented an update of the average ICP/XDR rate. The fix is simple: The code to update the average ICP/XDR rate is now called whenever a new, valid ICP/XDR rate is received, regardless of the source of the rate. What is the impact of this bug? The average ICP/XDR rate is used to determine [node provider remuneration](https://wiki.internetcomputer.org/wiki/Node_Provider_Remuneration) and [maturity modulation](https://wiki.internetcomputer.org/wiki/Maturity_modulation). Since only the rates for three days (May 9 - May 11) are not considered in the 30-day average rate, a back-of-the-envelope calculation (using the start-of-day rates on these days) reveals that the reported 30-day average ICP/XDR rate is, in fact, slightly too high, with a relative error of less than 1%, so the impact on node provider remuneration and maturity modulation is small. ## Submitted Proposal ````auto ## Proposal to Upgrade the Cycles-minting Canister ### Proposer: DFINITY Foundation ### Git Hash: e813c43a337a26c026c2f2ec19099bd2036e7280 ### New Wasm Hash: fc1655302a81cd1b7148a6f66479b2830bd0d567d04780720e7bdd6c5b124fb5 ### Upgrade Args Hash: 0fee102bd16b053022b69f2c65fd5e2f41d150ce9c214ac8731cfaf496ebda4e ### Target canister: rkp4c-7iaaa-aaaaa-aaaca-cai --- ## Features - Fix a bug in the Cycles-Minting Canister where the average ICP/XDR rate was not updated. ## Release Notes ``` $ git log --format="%C(auto) %h %s" 2ef275ecee0b8e2e6eba06d13ff4585ba8957f2e..e813c43a337a26c026c2f2ec19099bd2036e7280 -- ./rs/nns/cmc 6f1ce5e472 bugfix: Moving update_recent_icp_xdr_rates into set_icp_xdr_conversion_rate ``` ## Candid Post Upgrade Args ```candid () ``` ### Validating Candid Args Verify that the hash of the args matches proposal contents. `didc encode '()' | xxd -r -p | sha256sum` ## Wasm Verification Verify that the hash of the gzipped WASM matches the proposed hash. ``` git fetch git checkout e813c43a337a26c026c2f2ec19099bd2036e7280 ./gitlab-ci/container/build-ic.sh -c sha256sum ./artifacts/canisters/cycles-minting-canister.wasm.gz ``` ## Current Version - Current Git Hash: 2ef275ecee0b8e2e6eba06d13ff4585ba8957f2e - Current Wasm Hash: 3ff03b40f1c49b06e91a3c31879a21f6cead42be71d194d4d7e7becb8c60bd42 ```` ---
**Author:** ![DanielThurau](https://sea1.discourse-cdn.com/flex023/user_avatar/forum.dfinity.org/danielthurau/32/3879_2.png) [@DanielThurau](https://forum.dfinity.org/u/DanielThurau)\ **Post date:** [May 13, 2023, 1:24am UTC](https://forum.dfinity.org/t/nns-updates-may-12-cmc-hotfix/19943/2 "2023-05-13T01:24:04Z")
## Updated Hotfix Proposal Proposal [122286](https://dashboard.internetcomputer.org/proposal/122286) was submitted with an empty upgrade argument in the proposal. This proposal will be rejected by Dfinity. Proposal [122287](https://dashboard.internetcomputer.org/proposal/122287) was submitted with the following updated upgrade arg. ````auto ## Proposal to Upgrade the Cycles-minting Canister ### Proposer: DFINITY Foundation ### Git Hash: e813c43a337a26c026c2f2ec19099bd2036e7280 ### New Wasm Hash: fc1655302a81cd1b7148a6f66479b2830bd0d567d04780720e7bdd6c5b124fb5 ### Upgrade Args Hash: 5349c151a3353dd72f924409229c28f2ab1d9d70f8f8c7e81842ab5e18757803 ### Target canister: rkp4c-7iaaa-aaaaa-aaaca-cai --- ## Features - Fix a bug in the Cycles-Minting Canister where the average ICP/XDR rate was not updated. ## Release Notes ``` $ git log --format="%C(auto) %h %s" 2ef275ecee0b8e2e6eba06d13ff4585ba8957f2e..e813c43a337a26c026c2f2ec19099bd2036e7280 -- ./rs/nns/cmc 6f1ce5e472 bugfix: Moving update_recent_icp_xdr_rates into set_icp_xdr_conversion_rate ``` ## Candid Post Upgrade Args ```candid (record { governance_canister_id = principal "rrkah-fqaaa-aaaaa-aaaaq-cai"; ledger_canister_id = principal "ryjl3-tyaaa-aaaaa-aaaba-cai"; exchange_rate_canister = opt variant { Set = principal "uf6dk-hyaaa-aaaaq-qaaaq-cai" } }) ``` ### Validating Candid Args Verify that the hash of the args matches proposal contents. `didc encode '(record { governance_canister_id = principal "rrkah-fqaaa-aaaaa-aaaaq-cai"; ledger_canister_id = principal "ryjl3-tyaaa-aaaaa-aaaba-cai"; exchange_rate_canister = opt variant { Set = principal "uf6dk-hyaaa-aaaaq-qaaaq-cai" } })' | xxd -r -p | sha256sum` ## Wasm Verification Verify that the hash of the gzipped WASM matches the proposed hash. ``` git fetch git checkout e813c43a337a26c026c2f2ec19099bd2036e7280 ./gitlab-ci/container/build-ic.sh -c sha256sum ./artifacts/canisters/cycles-minting-canister.wasm.gz ``` ## Current Version - Current Git Hash: 2ef275ecee0b8e2e6eba06d13ff4585ba8957f2e - Current Wasm Hash: 3ff03b40f1c49b06e91a3c31879a21f6cead42be71d194d4d7e7becb8c60bd42 ````