NodeJS – 间歇性地出现“错误：此sockets已closures”

请参阅下面的错误，我正在调用一个nodeJS路由。 我在另一条路线也看到相同的exception。 两条路线都有做MongoDB操作的方法。 这是间歇性的，只发生在处理数据库中的值的两个API调用中。

{ date: 'Thu Sep 15 2016 04:16:46 GMT-0500 (EST)', process: { pid: 4424, uid: 0, gid: 0, cwd: '***rootFolder***', execPath: '/usr/bin/node', version: 'v6.3.1', argv: [ '/usr/bin/node', '**rootfolder**/app.js' ], memoryUsage: { rss: 104415232, heapTotal: 77893632, heapUsed: 60997696 } }, os: { loadavg: [ 0.03564453125, 0.06103515625, 0.0625 ], uptime: 3184925 }, trace: [ { column: 19, file: 'net.js', function: 'WriteStream.Socket._writeGeneric', line: 672, method: 'Socket._writeGeneric', native: false }, { column: 8, file: 'net.js', function: 'WriteStream.Socket._write', line: 724, method: 'Socket._write', native: false }, { column: 12, file: '_stream_writable.js', function: 'doWrite', line: 307, method: null, native: false }, { column: 5, file: '_stream_writable.js', function: 'writeOrBuffer', line: 293, method: null, native: false }, { column: 11, file: '_stream_writable.js', function: 'WriteStream.Writable.write', line: 220, method: 'Writable.write', native: false }, { column: 40, file: 'net.js', function: 'WriteStream.Socket.write', line: 650, method: 'Socket.write', native: false }, { column: 16, file: 'console.js', function: 'Console.warn', line: 51, method: 'warn', native: false }, { column: 43, file: '*****/node_modules/express/lib/application.js', function: 'EventEmitter.logerror', line: 629, method: 'logerror', native: false }, { column: 20, file: 'timers.js', function: 'runCallback', line: 576, method: null, native: false }, { column: 5, file: 'timers.js', function: 'tryOnImmediate', line: 550, method: null, native: false }, { column: 5, file: 'timers.js', function: 'processImmediate [as _immediateCallback]', line: 529, method: null, native: false } ], stack: [ 'Error: This socket is closed', ' at WriteStream.Socket._writeGeneric (net.js:672:19)', ' at WriteStream.Socket._write (net.js:724:8)', ' at doWrite (_stream_writable.js:307:12)', ' at writeOrBuffer (_stream_writable.js:293:5)', ' at WriteStream.Writable.write (_stream_writable.js:220:11)', ' at WriteStream.Socket.write (net.js:650:40)', ' at Console.warn (console.js:51:16)', ' at EventEmitter.logerror (***rootFolder***/node_modules/express/lib/application.js:629:43)', ' at runCallback (timers.js:576:20)', ' at tryOnImmediate (timers.js:550:5)', ' at processImmediate [as _immediateCallback] (timers.js:529:5)' ] }