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Liquidator & disputer bot: Improve bot gas estimation #1801

Merged
merged 19 commits into from
Aug 7, 2020
Merged

Liquidator & disputer bot: Improve bot gas estimation #1801

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dce1bae
set default block at beginning of update
nicholaspai Jul 31, 2020
de70443
change latest block syntax
nicholaspai Jul 31, 2020
290a9a1
Added gas estimation
chrismaree Aug 4, 2020
e56a9ed
refinement
chrismaree Aug 4, 2020
94825bf
moved gas estimation logic
chrismaree Aug 4, 2020
f5ed004
Added rounding
chrismaree Aug 4, 2020
d2e1c38
remove getCollateral() call; sort sponsor table by CR; only update EM…
nicholaspai Aug 5, 2020
482228e
push update threshold to 60
nicholaspai Aug 5, 2020
47b5a9e
merge
nicholaspai Aug 5, 2020
a7133e5
Added multiplier update
chrismaree Aug 5, 2020
357f52f
clean
chrismaree Aug 5, 2020
c5c9dab
Merge branch 'npai/liquidator-default-block' into chrismaree/patch-li…
chrismaree Aug 5, 2020
c47bea8
Restore ExpiringMultiPartyClient.js
chrismaree Aug 5, 2020
81a6d00
Restore SponsorReporter.js
chrismaree Aug 5, 2020
0fb1cf6
chnaged var scope
chrismaree Aug 5, 2020
e4391c6
Merge branch 'chrismaree/patch-liquidator-bot-gass-price' of github.c…
chrismaree Aug 5, 2020
e23c54d
Moved to constant
chrismaree Aug 6, 2020
7d4acdf
Update disputer/disputer.js
chrismaree Aug 7, 2020
7978564
Update liquidator/liquidator.js
chrismaree Aug 7, 2020
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15 changes: 11 additions & 4 deletions disputer/disputer.js
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Original file line number Diff line number Diff line change
Expand Up @@ -42,6 +42,9 @@ class Disputer {
this.toBN = this.web3.utils.toBN;
this.utf8ToHex = this.web3.utils.utf8ToHex;

// Multiplier to scale the amount of gas send with a transaction over and above the estimated gas from Truffle.
this.GAS_LIMIT_BUFFER = 1.25;

// Default config settings. Disputer deployer can override these settings by passing in new
// values via the `config` input object. The `isValid` property is a function that should be called
// before resetting any config settings. `isValid` must return a Boolean.
Expand Down Expand Up @@ -128,23 +131,26 @@ class Disputer {
const dispute = this.empContract.methods.dispute(disputeableLiquidation.id, disputeableLiquidation.sponsor);

// Simple version of inventory management: simulate the transaction and assume that if it fails, the caller didn't have enough collateral.
let gasLimit, totalPaid;
try {
await dispute.call({ from: this.account, gasPrice: this.gasEstimator.getCurrentFastPrice() });
totalPaid = await dispute.call({ from: this.account });
gasLimit = Math.floor((await dispute.estimateGas({ from: this.account })) * this.GAS_LIMIT_BUFFER);
} catch (error) {
this.logger.error({
at: "Disputer",
message: "Cannot dispute liquidation: not enough collateral (or large enough approval) to initiate dispute✋",
disputer: this.account,
sponsor: disputeableLiquidation.sponsor,
liquidation: disputeableLiquidation,
totalPaid,
error
});
continue;
}

const txnConfig = {
from: this.account,
gas: this.txnGasLimit,
gas: Math.min(gasLimit, this.txnGasLimit),
gasPrice: this.gasEstimator.getCurrentFastPrice()
};

Expand Down Expand Up @@ -223,9 +229,10 @@ class Disputer {
const withdraw = this.empContract.methods.withdrawLiquidation(liquidation.id, liquidation.sponsor);

// Confirm that dispute has eligible rewards to be withdrawn.
let withdrawAmount;
let withdrawAmount, gasLimit;
try {
withdrawAmount = revertWrapper(await withdraw.call({ from: this.account }));
gasLimit = Math.floor((await withdraw.estimateGas({ from: this.account })) * this.GAS_LIMIT_BUFFER);
if (withdrawAmount === null) {
throw new Error("Simulated reward withdrawal failed");
}
Expand All @@ -241,7 +248,7 @@ class Disputer {

const txnConfig = {
from: this.account,
gas: this.txnGasLimit,
gas: Math.min(gasLimit, this.txnGasLimit),
gasPrice: this.gasEstimator.getCurrentFastPrice()
};
this.logger.debug({
Expand Down
12 changes: 9 additions & 3 deletions liquidator/liquidator.js
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Original file line number Diff line number Diff line change
Expand Up @@ -52,6 +52,9 @@ class Liquidator {
this.fromWei = this.web3.utils.fromWei;
this.utf8ToHex = this.web3.utils.utf8ToHex;

// Multiplier to scale the amount of gas send with a transaction over and above the estimated gas from Truffle.
this.GAS_LIMIT_BUFFER = 1.25;

// Default config settings. Liquidator deployer can override these settings by passing in new
// values via the `config` input object. The `isValid` property is a function that should be called
// before resetting any config settings. `isValid` must return a Boolean.
Expand Down Expand Up @@ -248,8 +251,10 @@ class Liquidator {
);

// Simple version of inventory management: simulate the transaction and assume that if it fails, the caller didn't have enough collateral.
let gasLimit;
try {
await liquidation.call({ from: this.account });
gasLimit = Math.floor((await liquidation.estimateGas({ from: this.account })) * this.GAS_LIMIT_BUFFER);
} catch (error) {
this.logger.error({
at: "Liquidator",
Expand All @@ -268,7 +273,7 @@ class Liquidator {

const txnConfig = {
from: this.account,
gas: this.txnGasLimit,
gas: Math.min(gasLimit, this.txnGasLimit),
gasPrice: this.gasEstimator.getCurrentFastPrice()
};
this.logger.debug({
Expand Down Expand Up @@ -356,9 +361,10 @@ class Liquidator {
const withdraw = this.empContract.methods.withdrawLiquidation(liquidation.id, liquidation.sponsor);

// Confirm that liquidation has eligible rewards to be withdrawn.
let withdrawAmount;
let withdrawAmount, gasLimit;
try {
withdrawAmount = revertWrapper(await withdraw.call({ from: this.account }));
gasLimit = Math.floor((await withdraw.estimateGas({ from: this.account })) * this.GAS_LIMIT_BUFFER);
if (!withdrawAmount) {
throw new Error("Simulated reward withdrawal failed");
}
Expand All @@ -374,7 +380,7 @@ class Liquidator {

const txnConfig = {
from: this.account,
gas: this.txnGasLimit,
gas: Math.min(gasLimit, this.txnGasLimit),
gasPrice: this.gasEstimator.getCurrentFastPrice()
};
this.logger.debug({
Expand Down