@azure/cosmos
Version:
Microsoft Azure Cosmos DB Service Node.js SDK for NOSQL API
138 lines • 6.27 kB
JavaScript
"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
exports.PartitionKeyRangeFailoverInfo = void 0;
const tslib_1 = require("tslib");
// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.
const index_js_1 = require("./index.js");
const semaphore_1 = tslib_1.__importDefault(require("semaphore"));
/**
* @hidden
* This class manages the failover information for partition key ranges in Cosmos DB.
* It tracks the current endpoint, failed endpoints, and the number of consecutive read/write request failures.
*/
class PartitionKeyRangeFailoverInfo {
failedEndPoints = [];
currentEndPoint;
consecutiveReadRequestFailureCount = 0;
consecutiveWriteRequestFailureCount = 0;
firstRequestFailureTime = Date.now();
lastRequestFailureTime = Date.now();
failureCountSemaphore;
tryMoveNextLocationSemaphore;
/**
* @internal
*/
constructor(currentEndpoint) {
this.currentEndPoint = currentEndpoint;
this.failureCountSemaphore = (0, semaphore_1.default)(1);
this.tryMoveNextLocationSemaphore = (0, semaphore_1.default)(1);
}
/**
* Checks if the circuit breaker can trigger a partition failover based on the failure counts.
* Returns true if the number of consecutive failures exceeds the defined thresholds for read or write requests.
*/
async canCircuitBreakerTriggerPartitionFailOver(isReadOnlyRequest) {
const { consecutiveReadRequestFailureCount, consecutiveWriteRequestFailureCount } = await this.snapshotConsecutiveRequestFailureCount();
return isReadOnlyRequest
? consecutiveReadRequestFailureCount > index_js_1.Constants.ReadRequestFailureCountThreshold
: consecutiveWriteRequestFailureCount > index_js_1.Constants.WriteRequestFailureCountThreshold;
}
/**
* Increments the failure counts for read or write requests and updates the timestamps.
* If the time since the last failure exceeds the reset window, it resets the failure counts.
*/
async incrementRequestFailureCounts(isReadOnlyRequest, currentTimeInMilliseconds) {
return new Promise((resolve, reject) => {
this.failureCountSemaphore.take(async () => {
try {
const { lastRequestFailureTime } = await this.snapshotPartitionFailoverTimestamps();
if (currentTimeInMilliseconds - lastRequestFailureTime >
index_js_1.Constants.ConsecutiveFailureCountResetIntervalInMS) {
this.consecutiveReadRequestFailureCount = 0;
this.consecutiveWriteRequestFailureCount = 0;
}
if (isReadOnlyRequest) {
this.consecutiveReadRequestFailureCount++;
}
else {
this.consecutiveWriteRequestFailureCount++;
}
this.lastRequestFailureTime = currentTimeInMilliseconds;
return resolve();
}
catch (error) {
reject(error);
}
finally {
// Release the semaphore lock
this.failureCountSemaphore.leave();
}
});
});
}
/**
* Returns a snapshot of the first and last request failure timestamps.
* This method is used to retrieve the current state of failure timestamps without modifying them.
*/
async snapshotPartitionFailoverTimestamps() {
return {
firstRequestFailureTime: this.firstRequestFailureTime,
lastRequestFailureTime: this.lastRequestFailureTime,
};
}
/**
* Attempts to move to the next available location for the partition key range.
* If the current endpoint is the same as the failed endpoint, it tries to find a new endpoint
* from the provided list of endpoints. If a new endpoint is found, it updates the current endpoint
* and returns true. If no new endpoint is found, it returns false.
*/
async tryMoveNextLocation(endPoints, failedEndPoint, diagnosticNode, partitionKeyRangeId) {
if (failedEndPoint !== this.currentEndPoint) {
return true;
}
return new Promise((resolve, reject) => {
this.tryMoveNextLocationSemaphore.take(() => {
try {
for (const endpoint of endPoints) {
if (this.currentEndPoint === endpoint) {
continue;
}
if (this.failedEndPoints.includes(endpoint)) {
continue;
}
this.failedEndPoints.push(failedEndPoint);
this.currentEndPoint = endpoint;
return resolve(true);
}
diagnosticNode.addData({
partitionKeyRangeFailoverInfo: `PartitionKeyRangeId: ${partitionKeyRangeId}, failedLocations: ${this.failedEndPoints}, newLocation: ${this.currentEndPoint}`,
});
return resolve(false);
}
catch (err) {
reject(err);
}
finally {
this.tryMoveNextLocationSemaphore.leave();
}
});
});
}
/** Returns the current endpoint being used for partition key range operations.*/
getCurrentEndPoint() {
return this.currentEndPoint;
}
/**
* Returns a snapshot of the current consecutive request failure counts for read and write requests.
* This method is used to retrieve the current state of failure counts without modifying them.
*/
async snapshotConsecutiveRequestFailureCount() {
return {
consecutiveReadRequestFailureCount: this.consecutiveReadRequestFailureCount,
consecutiveWriteRequestFailureCount: this.consecutiveWriteRequestFailureCount,
};
}
}
exports.PartitionKeyRangeFailoverInfo = PartitionKeyRangeFailoverInfo;
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