Использую MongoClient PHP, всё работало хорошо до сегодняшнего дня, в один момент стала выскакивать ошибка
No suitable servers found (`serverSelectionTryOnce` set): [Server closed connection. calling ismaster on XX.XXX.XXX.XXX:27027]
В логах mongodb ошибки:
2017-04-21T18:35:11.407+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:11.987+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:12.593+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:13.173+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:13.752+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:14.359+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:14.969+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
2017-04-21T18:35:15.578+0200 I NETWORK [initandlisten] connection refused because too many open connections: 819
Как так может получиться? Можно ли увеличить лимит соединений?