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Merge pull request #4356 from mempool/mononaut/fix-pid-lock

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Recover from stale PID file
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wiz 2023-11-13 22:19:43 +09:00 committed by GitHub
commit cbe1ec4e72
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2 changed files with 28 additions and 10 deletions
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36
backend/src/database.ts
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@ -4,6 +4,7 @@ import config from './config';
import { createPool, Pool, PoolConnection } from 'mysql2/promise'; import { createPool, Pool, PoolConnection } from 'mysql2/promise';
import logger from './logger'; import logger from './logger';
import { FieldPacket, OkPacket, PoolOptions, ResultSetHeader, RowDataPacket } from 'mysql2/typings/mysql'; import { FieldPacket, OkPacket, PoolOptions, ResultSetHeader, RowDataPacket } from 'mysql2/typings/mysql';
import { execSync } from 'child_process';
class DB { class DB {
constructor() { constructor() {
@ -105,26 +106,43 @@ import { FieldPacket, OkPacket, PoolOptions, ResultSetHeader, RowDataPacket } fr
public getPidLock(): boolean { public getPidLock(): boolean {
const filePath = path.join(config.DATABASE.PID_DIR || __dirname, `/mempool-${config.DATABASE.DATABASE}.pid`); const filePath = path.join(config.DATABASE.PID_DIR || __dirname, `/mempool-${config.DATABASE.DATABASE}.pid`);
this.enforcePidLock(filePath);
fs.writeFileSync(filePath, `${process.pid}`);
return true;
}
private enforcePidLock(filePath: string): void {
if (fs.existsSync(filePath)) { if (fs.existsSync(filePath)) {
const pid = fs.readFileSync(filePath).toString(); const pid = parseInt(fs.readFileSync(filePath, 'utf-8'));
if (pid !== `${process.pid}`) { if (pid === process.pid) {
const msg = `Already running on PID ${pid} (or pid file '${filePath}' is stale)`; logger.warn('PID file already exists for this process');
return;
}
let cmd;
try {
cmd = execSync(`ps -p ${pid} -o args=`);
} catch (e) {
logger.warn(`Stale PID file at ${filePath}, but no process running on that PID ${pid}`);
return;
}
if (cmd && cmd.toString()?.includes('node')) {
const msg = `Another mempool nodejs process is already running on PID ${pid}`;
logger.err(msg); logger.err(msg);
throw new Error(msg); throw new Error(msg);
} else { } else {
return true; logger.warn(`Stale PID file at ${filePath}, but the PID ${pid} does not belong to a running mempool instance`);
} }
} else {
fs.writeFileSync(filePath, `${process.pid}`);
return true;
} }
} }
public releasePidLock(): void { public releasePidLock(): void {
const filePath = path.join(config.DATABASE.PID_DIR || __dirname, `/mempool-${config.DATABASE.DATABASE}.pid`); const filePath = path.join(config.DATABASE.PID_DIR || __dirname, `/mempool-${config.DATABASE.DATABASE}.pid`);
if (fs.existsSync(filePath)) { if (fs.existsSync(filePath)) {
const pid = fs.readFileSync(filePath).toString(); const pid = parseInt(fs.readFileSync(filePath, 'utf-8'));
if (pid === `${process.pid}`) { // only release our own pid file
if (pid === process.pid) {
fs.unlinkSync(filePath); fs.unlinkSync(filePath);
} }
} }

2
backend/src/index.ts
View File

@ -92,7 +92,7 @@ class Server {
logger.notice(`Starting Mempool Server${worker ? ' (worker)' : ''}... (${backendInfo.getShortCommitHash()})`); logger.notice(`Starting Mempool Server${worker ? ' (worker)' : ''}... (${backendInfo.getShortCommitHash()})`);
// Register cleanup listeners for exit events // Register cleanup listeners for exit events
['exit', 'SIGINT', 'SIGTERM', 'SIGUSR1', 'SIGUSR2', 'uncaughtException', 'unhandledRejection'].forEach(event => { ['exit', 'SIGHUP', 'SIGINT', 'SIGTERM', 'SIGUSR1', 'SIGUSR2', 'uncaughtException', 'unhandledRejection'].forEach(event => {
process.on(event, () => { this.onExit(event); }); process.on(event, () => { this.onExit(event); });
}); });