mirror of
https://github.com/gristlabs/grist-core.git
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fbae81648c
Summary: - /status accepts new optional query parameters: db=1, redis=1, and timeout=<ms> (defaults to 10_000). - These verify that the server can make trivial calls to DB/Redis, and that they return within the timeout. - New HealthCheck tests simulates DB and Redis problems. - Added resilience to Redis reconnects (helped by a test case that simulates disconnects) - When closing Redis-based session store, disconnect from Redis (to avoid hanging tests) Some associated test reorg: - Move stripeTools out of test/nbrowser, and remove an unnecessary dependency, to avoid starting up browser for gen-server tests. - Move TcpForwarder to its own file, to use in the new test. Test Plan: Added a new HealthCheck test that simulates DB and Redis problems. Reviewers: georgegevoian Reviewed By: georgegevoian Differential Revision: https://phab.getgrist.com/D4054
577 lines
23 KiB
TypeScript
577 lines
23 KiB
TypeScript
import {MapWithTTL} from 'app/common/AsyncCreate';
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import * as version from 'app/common/version';
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import {DocStatus, DocWorkerInfo, IDocWorkerMap} from 'app/server/lib/DocWorkerMap';
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import log from 'app/server/lib/log';
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import {checkPermitKey, formatPermitKey, IPermitStore, Permit} from 'app/server/lib/Permit';
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import {promisifyAll} from 'bluebird';
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import mapValues = require('lodash/mapValues');
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import {createClient, Multi, RedisClient} from 'redis';
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import Redlock from 'redlock';
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import uuidv4 from 'uuid/v4';
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promisifyAll(RedisClient.prototype);
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promisifyAll(Multi.prototype);
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// Max time for which we will hold a lock, by default. In milliseconds.
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const LOCK_TIMEOUT = 3000;
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// How long do checksums stored in redis last. In milliseconds.
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// Should be long enough to allow S3 to reach consistency with very high probability.
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// Consistency failures shorter than this interval will be detectable, failures longer
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// than this interval will not be detectable.
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const CHECKSUM_TTL_MSEC = 24 * 60 * 60 * 1000; // 24 hours
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// How long do permits stored in redis last, in milliseconds.
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const PERMIT_TTL_MSEC = 1 * 60 * 1000; // 1 minute
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class DummyDocWorkerMap implements IDocWorkerMap {
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private _worker?: DocWorkerInfo;
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private _available: boolean = false;
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private _elections = new MapWithTTL<string, string>(1); // default ttl never used
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private _permitStores = new Map<string, IPermitStore>();
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public async getDocWorker(docId: string) {
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if (!this._worker) { throw new Error('no workers'); }
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return {docMD5: 'unknown', docWorker: this._worker, isActive: true};
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}
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public async assignDocWorker(docId: string) {
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if (!this._worker || !this._available) { throw new Error('no workers'); }
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return {docMD5: 'unknown', docWorker: this._worker, isActive: true};
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}
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public async getDocWorkerOrAssign(docId: string, workerId: string): Promise<DocStatus> {
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if (!this._worker || !this._available) { throw new Error('no workers'); }
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if (this._worker.id !== workerId) { throw new Error('worker not known'); }
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return {docMD5: 'unknown', docWorker: this._worker, isActive: true};
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}
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public async updateDocStatus(docId: string, checksum: string) {
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// nothing to do
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}
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public async addWorker(info: DocWorkerInfo): Promise<void> {
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this._worker = info;
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}
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public async removeWorker(workerId: string): Promise<void> {
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this._worker = undefined;
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}
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public async setWorkerAvailability(workerId: string, available: boolean): Promise<void> {
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this._available = available;
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}
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public async releaseAssignment(workerId: string, docId: string): Promise<void> {
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// nothing to do
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}
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public async getAssignments(workerId: string): Promise<string[]> {
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return [];
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}
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public getPermitStore(prefix: string, defaultTtlMs?: number): IPermitStore {
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let store = this._permitStores.get(prefix);
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if (store) { return store; }
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const _permits = new MapWithTTL<string, string>(defaultTtlMs || PERMIT_TTL_MSEC);
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store = {
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async setPermit(permit: Permit, ttlMs?: number): Promise<string> {
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const key = formatPermitKey(uuidv4(), prefix);
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if (ttlMs) {
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_permits.setWithCustomTTL(key, JSON.stringify(permit), ttlMs);
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} else {
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_permits.set(key, JSON.stringify(permit));
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}
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return key;
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},
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async getPermit(key: string): Promise<Permit> {
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const result = _permits.get(key);
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return result ? JSON.parse(result) : null;
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},
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async removePermit(key: string): Promise<void> {
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_permits.delete(key);
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},
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async close(): Promise<void> {
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_permits.clear();
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},
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getKeyPrefix() {
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return formatPermitKey('', prefix);
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}
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};
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this._permitStores.set(prefix, store);
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return store;
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}
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public async close(): Promise<void> {
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await Promise.all([...this._permitStores.values()].map(store => store.close()));
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this._permitStores.clear();
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this._elections.clear();
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}
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public async getElection(name: string, durationInMs: number): Promise<string|null> {
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if (this._elections.get(name)) { return null; }
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const key = uuidv4();
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this._elections.setWithCustomTTL(name, key, durationInMs);
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return key;
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}
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public async removeElection(name: string, electionKey: string): Promise<void> {
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if (this._elections.get(name) === electionKey) {
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this._elections.delete(name);
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}
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}
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public async updateChecksum(family: string, key: string, checksum: string) {
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// nothing to do
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}
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public async getChecksum(family: string, key: string) {
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return null;
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}
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public async getWorkerGroup(workerId: string): Promise<string|null> {
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return null;
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}
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public async getDocGroup(docId: string): Promise<string|null> {
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return null;
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}
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public async updateDocGroup(docId: string, docGroup: string): Promise<void> {
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// nothing to do
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}
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public async removeDocGroup(docId: string): Promise<void> {
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// nothing to do
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}
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public getRedisClient() {
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return null;
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}
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}
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/**
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* Manage the relationship between document and workers. Backed by Redis.
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* Can also assign workers to "groups" for serving particular documents.
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* Keys used:
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* workers - the set of known active workers, identified by workerId
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* workers-available - the set of workers available for assignment (a subset of the workers set)
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* workers-available-{group} - the set of workers available for a given group
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* worker-{workerId} - a hash of contact information for a worker
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* worker-{workerId}-docs - a set of docs assigned to a worker, identified by docId
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* worker-{workerId}-group - if set, marks the worker as serving a particular group
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* doc-${docId} - a hash containing (JSON serialized) DocStatus fields, other than docMD5.
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* doc-${docId}-checksum - the docs docMD5, or 'null' if docMD5 is null
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* doc-${docId}-group - if set, marks the doc as to be served by workers in a given group
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* workers-lock - a lock used when working with the list of workers
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* groups - a hash from groupIds (arbitrary strings) to desired number of workers in group
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* elections-${deployment} - a hash, from groupId to a (serialized json) list of worker ids
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*
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* Assignments of documents to workers can end abruptly at any time. Clients
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* should be prepared to retry if a worker is not responding or denies that a document
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* is assigned to it.
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*
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* If the groups key is set, workers assign themselves to groupIds to
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* fill the counts specified in groups (in order of groupIds), and
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* once those are exhausted, get assigned to the special group
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* "default".
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*/
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export class DocWorkerMap implements IDocWorkerMap {
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private _client: RedisClient;
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private _clients: RedisClient[];
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private _redlock: Redlock;
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// Optional deploymentKey argument supplies a key unique to the deployment (this is important
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// for maintaining groups across redeployments only)
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constructor(_clients?: RedisClient[], private _deploymentKey?: string, private _options?: {
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permitMsec?: number
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}) {
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this._deploymentKey = this._deploymentKey || version.version;
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this._clients = _clients || [createClient(process.env.REDIS_URL)];
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this._redlock = new Redlock(this._clients);
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this._client = this._clients[0]!;
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this._client.on('error', (err) => log.warn(`DocWorkerMap: redisClient error`, String(err)));
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this._client.on('end', () => log.warn(`DocWorkerMap: redisClient connection closed`));
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this._client.on('reconnecting', () => log.warn(`DocWorkerMap: redisClient reconnecting`));
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}
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public async addWorker(info: DocWorkerInfo): Promise<void> {
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log.info(`DocWorkerMap.addWorker ${info.id}`);
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const lock = await this._redlock.lock('workers-lock', LOCK_TIMEOUT);
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try {
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// Make a worker-{workerId} key with contact info.
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await this._client.hmsetAsync(`worker-${info.id}`, info);
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// Add this worker to set of workers (but don't make it available for work yet).
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await this._client.saddAsync('workers', info.id);
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if (info.group) {
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// Accept work only for a specific group.
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// Do not accept work not associated with the specified group.
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await this._client.setAsync(`worker-${info.id}-group`, info.group);
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} else {
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// Figure out if worker should belong to a group via elections.
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// Be careful: elections happen within a single deployment, so are somewhat
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// unintuitive in behavior. For example, if a document is assigned to a group
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// but there is no worker available for that group, it may open on any worker.
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// And if a worker is assigned to a group, it may still end up assigned work
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// not associated with that group if it is the only worker available.
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const groups = await this._client.hgetallAsync('groups');
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if (groups) {
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const elections = await this._client.hgetallAsync(`elections-${this._deploymentKey}`) || {};
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for (const group of Object.keys(groups).sort()) {
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const count = parseInt(groups[group], 10) || 0;
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if (count < 1) { continue; }
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const elected: string[] = JSON.parse(elections[group] || '[]');
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if (elected.length >= count) { continue; }
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elected.push(info.id);
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await this._client.setAsync(`worker-${info.id}-group`, group);
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await this._client.hsetAsync(`elections-${this._deploymentKey}`, group, JSON.stringify(elected));
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break;
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}
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}
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}
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} finally {
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await lock.unlock();
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}
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}
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public async removeWorker(workerId: string): Promise<void> {
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log.info(`DocWorkerMap.removeWorker ${workerId}`);
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const lock = await this._redlock.lock('workers-lock', LOCK_TIMEOUT);
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try {
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// Drop out of available set first.
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await this._client.sremAsync('workers-available', workerId);
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const group = await this._client.getAsync(`worker-${workerId}-group`) || 'default';
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await this._client.sremAsync(`workers-available-${group}`, workerId);
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// At this point, this worker should no longer be receiving new doc assignments, though
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// clients may still be directed to the worker.
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// If we were elected for anything, back out.
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const elections = await this._client.hgetallAsync(`elections-${this._deploymentKey}`);
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if (elections) {
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if (group in elections) {
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const elected: string[] = JSON.parse(elections[group]);
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const newElected = elected.filter(worker => worker !== workerId);
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if (elected.length !== newElected.length) {
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if (newElected.length > 0) {
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await this._client.hsetAsync(`elections-${this._deploymentKey}`, group,
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JSON.stringify(newElected));
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} else {
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await this._client.hdelAsync(`elections-${this._deploymentKey}`, group);
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delete elections[group];
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}
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}
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// We're the last one involved in elections - remove the key entirely.
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if (Object.keys(elected).length === 0) {
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await this._client.delAsync(`elections-${this._deploymentKey}`);
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}
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}
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}
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// Now, we start removing the assignments.
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const assignments = await this._client.smembersAsync(`worker-${workerId}-docs`);
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if (assignments) {
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const op = this._client.multi();
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for (const doc of assignments) { op.del(`doc-${doc}`); }
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await op.execAsync();
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}
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// Now remove worker-{workerId}* keys.
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await this._client.delAsync(`worker-${workerId}-docs`);
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await this._client.delAsync(`worker-${workerId}-group`);
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await this._client.delAsync(`worker-${workerId}`);
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// Forget about this worker completely.
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await this._client.sremAsync('workers', workerId);
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} finally {
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await lock.unlock();
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}
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}
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public async setWorkerAvailability(workerId: string, available: boolean): Promise<void> {
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log.info(`DocWorkerMap.setWorkerAvailability ${workerId} ${available}`);
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const group = await this._client.getAsync(`worker-${workerId}-group`) || 'default';
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if (available) {
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const docWorker = await this._client.hgetallAsync(`worker-${workerId}`) as DocWorkerInfo|null;
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if (!docWorker) { throw new Error('no doc worker contact info available'); }
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await this._client.saddAsync(`workers-available-${group}`, workerId);
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// If we're not assigned exclusively to a group, add this worker also to the general
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// pool of workers.
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if (!docWorker.group) {
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await this._client.saddAsync('workers-available', workerId);
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}
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} else {
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await this._client.sremAsync('workers-available', workerId);
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await this._client.sremAsync(`workers-available-${group}`, workerId);
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}
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}
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public async releaseAssignment(workerId: string, docId: string): Promise<void> {
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const op = this._client.multi();
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op.del(`doc-${docId}`);
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op.srem(`worker-${workerId}-docs`, docId);
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await op.execAsync();
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}
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public async getAssignments(workerId: string): Promise<string[]> {
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return this._client.smembersAsync(`worker-${workerId}-docs`);
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}
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/**
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* Defined by IDocWorkerMap.
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*
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* Looks up which DocWorker is responsible for this docId.
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* Responsibility could change at any time after this call, so it
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* should be treated as a hint, and clients should be prepared to be
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* refused and need to retry.
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*/
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public async getDocWorker(docId: string): Promise<DocStatus|null> {
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const {doc} = await this._getDocAndChecksum(docId);
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return doc;
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}
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/**
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*
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* Defined by IDocWorkerMap.
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*
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* Assigns a DocWorker to this docId if one is not yet assigned.
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* Note that the assignment could be unmade at any time after this
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* call if the worker dies, is brought down, or for other potential
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* reasons in the future such as migration of individual documents
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* between workers.
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*
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* A preferred doc worker can be specified, which will be assigned
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* if no assignment is already made.
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*
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* For the special docId "import", return a potential assignment.
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* It will be up to the doc worker to assign the eventually
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* created document, if desired.
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*
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*/
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public async assignDocWorker(docId: string, workerId?: string): Promise<DocStatus> {
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if (docId === 'import') {
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const lock = await this._redlock.lock(`workers-lock`, LOCK_TIMEOUT);
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try {
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const _workerId = await this._client.srandmemberAsync(`workers-available-default`);
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if (!_workerId) { throw new Error('no doc worker available'); }
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const docWorker = await this._client.hgetallAsync(`worker-${_workerId}`) as DocWorkerInfo|null;
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if (!docWorker) { throw new Error('no doc worker contact info available'); }
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return {
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docMD5: null,
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docWorker,
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isActive: false
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};
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} finally {
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await lock.unlock();
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}
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}
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// Check if a DocWorker is already assigned; if so return result immediately
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// without locking.
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let docStatus = await this.getDocWorker(docId);
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if (docStatus) { return docStatus; }
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// No assignment yet, so let's lock and set an assignment up.
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const lock = await this._redlock.lock(`workers-lock`, LOCK_TIMEOUT);
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try {
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// Now that we've locked, recheck that the worker hasn't been reassigned
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// in the meantime. Return immediately if it has.
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const docAndChecksum = await this._getDocAndChecksum(docId);
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docStatus = docAndChecksum.doc;
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if (docStatus) { return docStatus; }
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if (!workerId) {
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// Check if document has a preferred worker group set.
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const group = await this._client.getAsync(`doc-${docId}-group`) || 'default';
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// Let's start off by assigning documents to available workers randomly.
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// TODO: use a smarter algorithm.
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workerId = await this._client.srandmemberAsync(`workers-available-${group}`) || undefined;
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if (!workerId) {
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// No workers available in the desired worker group. Rather than refusing to
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// open the document, we fall back on assigning a worker from any of the workers
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// available, regardless of grouping.
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// This limits the impact of operational misconfiguration (bad redis setup,
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// or not starting enough workers). It has the downside of potentially disguising
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// problems, so we log a warning.
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log.warn(`DocWorkerMap.assignDocWorker ${docId} found no workers for group ${group}`);
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workerId = await this._client.srandmemberAsync('workers-available') || undefined;
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}
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if (!workerId) { throw new Error('no doc workers available'); }
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} else {
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if (!await this._client.sismemberAsync('workers-available', workerId)) {
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throw new Error(`worker ${workerId} not known or not available`);
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}
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}
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// Look up how to contact the worker.
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const docWorker = await this._client.hgetallAsync(`worker-${workerId}`) as DocWorkerInfo|null;
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if (!docWorker) { throw new Error('no doc worker contact info available'); }
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// We can now construct a DocStatus, preserving any existing checksum.
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const checksum = docAndChecksum.checksum;
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const newDocStatus = {docMD5: checksum, docWorker, isActive: true};
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// We add the assignment to worker-{workerId}-docs and save doc-{docId}.
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const result = await this._client.multi()
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.sadd(`worker-${workerId}-docs`, docId)
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.hmset(`doc-${docId}`, {
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docWorker: JSON.stringify(docWorker), // redis can't store nested objects, strings only
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isActive: JSON.stringify(true) // redis can't store booleans, strings only
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})
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.setex(`doc-${docId}-checksum`, CHECKSUM_TTL_MSEC / 1000.0, checksum || 'null')
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.execAsync();
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if (!result) { throw new Error('failed to store new assignment'); }
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return newDocStatus;
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} finally {
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await lock.unlock();
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}
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}
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/**
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*
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* Defined by IDocWorkerMap.
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*
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* Assigns a specific DocWorker to this docId if one is not yet assigned.
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*
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*/
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public async getDocWorkerOrAssign(docId: string, workerId: string): Promise<DocStatus> {
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return this.assignDocWorker(docId, workerId);
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}
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public async updateDocStatus(docId: string, checksum: string): Promise<void> {
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return this.updateChecksum('doc', docId, checksum);
|
|
}
|
|
|
|
public async updateChecksum(family: string, key: string, checksum: string) {
|
|
await this._client.setexAsync(`${family}-${key}-checksum`, CHECKSUM_TTL_MSEC / 1000.0, checksum);
|
|
}
|
|
|
|
public async getChecksum(family: string, key: string) {
|
|
const checksum = await this._client.getAsync(`${family}-${key}-checksum`);
|
|
return checksum === 'null' ? null : checksum;
|
|
}
|
|
|
|
public getPermitStore(prefix: string, defaultTtlMs?: number): IPermitStore {
|
|
const permitMsec = defaultTtlMs || (this._options && this._options.permitMsec) || PERMIT_TTL_MSEC;
|
|
const client = this._client;
|
|
return {
|
|
async setPermit(permit: Permit, ttlMs?: number): Promise<string> {
|
|
const key = formatPermitKey(uuidv4(), prefix);
|
|
// seems like only integer seconds are supported?
|
|
const duration = ttlMs || permitMsec;
|
|
await client.setexAsync(key, Math.ceil(duration / 1000.0), JSON.stringify(permit));
|
|
return key;
|
|
},
|
|
async getPermit(key: string): Promise<Permit|null> {
|
|
if (!checkPermitKey(key, prefix)) { throw new Error('permit could not be read'); }
|
|
const result = await client.getAsync(key);
|
|
return result && JSON.parse(result);
|
|
},
|
|
async removePermit(key: string): Promise<void> {
|
|
if (!checkPermitKey(key, prefix)) { throw new Error('permit could not be read'); }
|
|
await client.delAsync(key);
|
|
},
|
|
async close() {
|
|
// nothing to do
|
|
},
|
|
getKeyPrefix() {
|
|
return formatPermitKey('', prefix);
|
|
}
|
|
};
|
|
}
|
|
|
|
public async close(): Promise<void> {
|
|
for (const cli of this._clients || []) {
|
|
await cli.quitAsync();
|
|
}
|
|
}
|
|
|
|
public async getElection(name: string, durationInMs: number): Promise<string|null> {
|
|
// Could use "set nx" for election, but redis docs don't encourage that any more,
|
|
// favoring redlock:
|
|
// https://redis.io/commands/setnx#design-pattern-locking-with-codesetnxcode
|
|
const redisKey = `nomination-${name}`;
|
|
const lock = await this._redlock.lock(`${redisKey}-lock`, LOCK_TIMEOUT);
|
|
try {
|
|
if (await this._client.getAsync(redisKey) !== null) { return null; }
|
|
const electionKey = uuidv4();
|
|
// seems like only integer seconds are supported?
|
|
await this._client.setexAsync(redisKey, Math.ceil(durationInMs / 1000.0), electionKey);
|
|
return electionKey;
|
|
} finally {
|
|
await lock.unlock();
|
|
}
|
|
}
|
|
|
|
public async removeElection(name: string, electionKey: string): Promise<void> {
|
|
const redisKey = `nomination-${name}`;
|
|
const lock = await this._redlock.lock(`${redisKey}-lock`, LOCK_TIMEOUT);
|
|
try {
|
|
const current = await this._client.getAsync(redisKey);
|
|
if (current === electionKey) {
|
|
await this._client.delAsync(redisKey);
|
|
} else if (current !== null) {
|
|
throw new Error('could not remove election');
|
|
}
|
|
} finally {
|
|
await lock.unlock();
|
|
}
|
|
}
|
|
|
|
public async getWorkerGroup(workerId: string): Promise<string|null> {
|
|
return this._client.getAsync(`worker-${workerId}-group`);
|
|
}
|
|
|
|
public async getDocGroup(docId: string): Promise<string|null> {
|
|
return this._client.getAsync(`doc-${docId}-group`);
|
|
}
|
|
|
|
public async updateDocGroup(docId: string, docGroup: string): Promise<void> {
|
|
await this._client.setAsync(`doc-${docId}-group`, docGroup);
|
|
}
|
|
|
|
public async removeDocGroup(docId: string): Promise<void> {
|
|
await this._client.delAsync(`doc-${docId}-group`);
|
|
}
|
|
|
|
public getRedisClient(): RedisClient {
|
|
return this._client;
|
|
}
|
|
|
|
/**
|
|
* Fetch the doc-<docId> hash and doc-<docId>-checksum key from redis.
|
|
* Return as a decoded DocStatus and a checksum.
|
|
*/
|
|
private async _getDocAndChecksum(docId: string): Promise<{
|
|
doc: DocStatus|null,
|
|
checksum: string|null,
|
|
}> {
|
|
// Fetch the various elements that go into making a DocStatus
|
|
const props = await this._client.multi()
|
|
.hgetall(`doc-${docId}`)
|
|
.get(`doc-${docId}-checksum`)
|
|
.execAsync() as [{[key: string]: any}|null, string|null]|null;
|
|
// Fields are JSON encoded since redis cannot store them directly.
|
|
const doc = props?.[0] ? mapValues(props[0], (val) => JSON.parse(val)) as DocStatus : null;
|
|
// Redis cannot store a null value, so we encode it as 'null', which does
|
|
// not match any possible MD5.
|
|
const checksum = (props?.[1] === 'null' ? null : props?.[1]) || null;
|
|
if (doc) { doc.docMD5 = checksum; } // the checksum goes in the DocStatus too.
|
|
return {doc, checksum};
|
|
}
|
|
}
|
|
|
|
// If we don't have redis available and use a DummyDocWorker, it should be a singleton.
|
|
let dummyDocWorkerMap: DummyDocWorkerMap|null = null;
|
|
|
|
export function getDocWorkerMap(): IDocWorkerMap {
|
|
if (process.env.REDIS_URL) {
|
|
return new DocWorkerMap();
|
|
} else {
|
|
dummyDocWorkerMap = dummyDocWorkerMap || new DummyDocWorkerMap();
|
|
return dummyDocWorkerMap;
|
|
}
|
|
}
|