How to check if a validator is missing blocks
As a validator in the network if you miss a certain amount of blocks consecutively your node can be penalized.
Getting the max amount of missed blocks before a penalty
To check how many blocks you need to miss consecutively to be penalized we need to call the getNetworkInfo method of the chain SCORE like in the following example:
curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"icx_call","id":218,"params":{"to":"cx0000000000000000000000000000000000000000","dataType":"call","data":{"method":"getNetworkInfo"}}}' https://ctz.solidwallet.io/api/v3The response of the call is a JSON object in the following format:
{
"jsonrpc": "2.0",
"result": {
"bondRequirement": "0x5",
"consistentValidationPenaltyCondition": "0x5",
"consistentValidationPenaltyMask": "0x1e",
"consistentValidationPenaltySlashRatio": "0x0",
"delegationSlotMax": "0x64",
"extraMainPRepCount": "0x3",
"iissVersion": "0x3",
"irep": "0x21e19e0c9bab2400000",
"lockMaxMultiplier": "0x14",
"lockMinMultiplier": "0x5",
"mainPRepCount": "0x16",
"preps": "0x9b",
"proposalNonVotePenaltySlashRatio": "0x0",
"rewardFund": {
"Icps": "0xa",
"Iglobal": "0x27b46536c66c8e3000000",
"Iprep": "0xd",
"Irelay": "0x0",
"Ivoter": "0x4d"
},
"rrep": "0x4b0",
"subPRepCount": "0x4e",
"termPeriod": "0xa870",
"totalBonded": "0xe4587961c063648044000",
"totalDelegated": "0x12cbcf6707967830bfccef7",
"totalPower": "0xf562e99c53b58009778878",
"totalStake": "0x14d8b283f6e8cf32af44c2a",
"unbondingMax": "0x64",
"unbondingPeriodMultiplier": "0x7",
"unstakeSlotMax": "0x3e8",
"validationPenaltyCondition": "0x294"
},
"id": 218
}Converting the value of validationPenaltyCondition from hex to an integer will result in 660, this is the amount of consecutive blocks that a validator must miss to receive a penalty.
Check how many blocks a node has missed
Now that we know the amount of blocks that a node needs to miss to get a penalty, to check if a validator is currently missing blocks we need to make 2 RPC calls:
getPRepTerm: The response of this call returns an array of all the validators in the network in the order they are currently ranked in the chain, and shows the names of the validators.getPRepStats: The response of this call returns an assortment of data related to block validation including the blocks the validator has missed but doesn't show the name of the validator.
Making the 2 RPC calls is necessary because both responses have the validators in an array ordered in the same way (according to their rank) but the getPRepStats call doesn't show the name of the validator. These calls are necessary to be made consecutively, or be made targeting the same specific block to ensure that the order of both responses are the same.
RPC call for the getPRepTerm method:
curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"icx_call","id":142,"params":{"to":"cx0000000000000000000000000000000000000000","dataType":"call","data":{"method":"getPRepTerm"}}}' https://ctz.solidwallet.io/api/v3Response:
{
"jsonrpc": "2.0",
"result": {
"blockHeight": "0x3bfce3d",
"bondRequirement": "0x5",
"endBlockHeight": "0x3c02a32",
"iissVersion": "0x3",
"irep": "0x0",
"isDecentralized": "0x1",
"mainPRepCount": "0x19",
"period": "0xa870",
"preps": [
{
"address": "hx0b047c751658f7ce1b2595da34d57a0e7dad357d",
"bonded": "0x1a784379d99db42000000",
"city": "Zug",
"country": "CHE",
"delegated": "0x1f98e638c29c0959d56dab",
"details": "https://icon.foundation/prep/details.json",
"email": "hello@icon.foundation",
"grade": "0x0",
"irep": "0x2f6f10780d22cc00000",
"irepUpdateBlockHeight": "0x12a8eb8",
"lastHeight": "0x3bfc491",
"name": "ICON Foundation",
"nodeAddress": "hx9c63f73d3c564a54d0eed84f90718b1ebed16f09",
"p2pEndpoint": "18.176.121.232:7100",
"penalty": "0x0","power": "0x2116545850052128000000",
"status": "0x0",
"totalBlocks": "0x31d6f0d",
"validatedBlocks": "0x31afc87",
"website": "https://icon.foundation"
}
...
],
"revision": "0x14",
"rewardFund": {
"Icps": "0xa",
"Iglobal": "0x27b46536c66c8e3000000",
"Iprep": "0xd",
"Irelay": "0x0",
"Ivoter": "0x4d"
},
"rrep": "0x0",
"sequence": "0x4c2",
"startBlockHeight": "0x3bf81c3",
"totalDelegated": "0x12cbf923eb2714cfa96e81c",
"totalPower": "0xf5623e3f106a1eed7ea5dd",
"totalSupply": "0x31a10f1cd3229dcff7677ae"
},
"id": 142
}RPC call for the getPRepStats method:
curl -X POST -H "Content-Type: application/json" --data '{"jsonrpc":"2.0","method":"icx_call","id":142,"params":{"to":"cx0000000000000000000000000000000000000000","dataType":"call","data":{"method":"getPRepStats"}}}' https://ctz.solidwallet.io/api/v3Response:
{
"jsonrpc": "2.0",
"result": {
"blockHeight": "0x3bfcfea",
"preps": [
{
"fail": "0x27286",
"failCont": "0x0",
"grade": "0x0",
"lastHeight": "0x3bfc491",
"lastState": "0x2",
"penalties": "0x0",
"realFail": "0x27286",
"realFailCont": "0x0",
"realTotal": "0x31d70ba",
"status": "0x0",
"total": "0x31d6561"
},
...
]
},
"id": 142
}Example using JavaScript
Once we have the result of the 3 RPC calls (getNetworkInfo, getPRepTerm and getPRepStats) we can use this information to create a function that will give us the max amount of blocks a validator can miss before getting a penalty and how many blocks each validator had missed consecutively.
Javascript function to merge getPRepTerm and getPRepStats:
function getPRepsFullInfo(prepTerm, prepStats) {
const result = [];
for (let i = 0; i < prepTerm.preps.length; i++) {
result.push({
...prepTerm.preps[i],
...prepStats.preps[i]
});
}
return result;
}Once we have the result of getPRepsFullInfo we can get the count of missing blocks on each validator using the following function:
function getPRepsMissingBlocks(prepsFullInfo) {
const result = [];
for (const prep of prepsFullInfo) {
if (prep.realFailCont != "0x0") {
result.push({
name: prep.name,
realFailCont: prep.realFailCont
});
}
}
return result;
}We can use the following function to merge the network data and the validator data:
function getCountdownToPenalty(networkInfo, prepsFullInfo) {
const result = [];
const vpCondition = parseInt(networkInfo.validationPenaltyCondition, 16);
for (const prep of prepsFullInfo) {
result.push({
address: prep.address,
name: prep.name,
realFailCont: parseInt(prep.realFailCont, 16)
});
}
return {
validationPenaltyCondition: vpCondition,
preps: result
};
}The result of this function call will be the following:
{
validationPenaltyCondition: 660,
preps: [
{
address: 'hx0b047c751658f7ce1b2595da34d57a0e7dad357d',
name: 'ICON Foundation',
realFailCont: 0
},
{
address: 'hxfba37e91ccc13ec1dab115811f73e429cde44d48',
name: 'Lydia Labs',
realFailCont: 0
},
{
address: 'hxf680ae11372c48afebbce77c9d8de455e1acc18a',
name: 'GROW',
realFailCont: 0
},
{
address: 'hx1b5c004de7b8591cb571f004fdfa00d74d1099e6',
name: 'Binance Node',
realFailCont: 0
},
{
address: 'hx3d5c3ce7554f4d762f6396e53b2c5de07074ec39',
name: 'ICON DAO',
realFailCont: 0
},
{
address: 'hx3c58970034d5a923aa95058365450feed28979a2',
name: 'GangstaVerse',
realFailCont: 0
},
...
]
}The validators will receive a penalty once their realFailCont ≥ validationPenaltyCondition