Intermittent connection errors on PHP

Freek_Vandeursen · 2021-01-19T10:45:18.097Z

Hello community,

I hope someone will be able to help me debug some connection errors in our PHP application.

Our connection between PHP and MongoDB is working fine most of the time. However, some requests fail with either the following error messages:

No suitable servers found (serverSelectionTryOnce set): [socket timeout calling ismaster on ‘:27017’]
No servers yet eligible for rescan

I have found multiple mentions of these errors online, but they all deal with situations where every requests fails. I haven’t found a reason yet why most requests would work normally, but some fail.

Our environment:

Mongo server 4.4 (single instance, no cluster)
Mongo PHP driver 1.8.2
Mongo PHP library 1.8.0

What can I do to debug this issue?

Dominic_Taylor · 2022-02-24T17:47:36.868Z

did you find a resolution?

Freek_Vandeursen · 2022-02-25T12:24:26.147Z

Unfortunately not @Dominic_Taylor . Tweaking timeout seemed to reduce it a bit, but I didn’t manage to get rid of those errors completely.

Diego_Chicaiza · 2022-12-08T19:04:38.122Z

it will be great finding a solution on this

Hubert_Nguyen1 · 2022-12-16T20:38:24.584Z

Welcome to the MongoDB community forums @Diego_Chicaiza !

@Freek_Vandeursen , are you using a self-hosted MongoDB server?

I was also wondering if this happens when under heavy load, or just randomly when there’s no reason to run out of available connections/resources that might cause intermittent issues. What’s an approximate ratio of success vs. fail in your opinion?

Julian_G · 2023-08-24T07:50:50.166Z

Hello, have you found a solution for this error? The same thing is happening to me. I have PHP version 7.4 and I’m using the mongo driver with version 1.6.1

alexis_bonnyaud · 2024-03-03T10:25:11.669Z

Bonjour, je rencontre exactement le même problème. Le serveur MongoDB n’est pas installé sur mon serveur comme j’utilise ScaleGrid. J’ai installé uniquement le driver PHP officiel pour MongoDB. La plupart du temps ça fonctionne mais très aléatoirement je rencontre l’erreur : PHP Fatal error: Uncaught MongoDB\Driver\Exception\ConnectionTimeoutException: No suitable servers found (serverSelectionTryOnce set): [Failed to resolve ‘sg-hebergemeweb2-48289.servers.mongodirector.com’] [Failed to resolve ‘sg-hebergemeweb2-48290.servers.mongodirector.com’] [Failed to resolve ‘sg-hebergemeweb2-48291.servers.mongodirector.com’]

J’utilise MongoDB 4.2 et le driver PHP 1.15.0 (je viens de le mettre à jour vers 1.17.2 pour voir si ça change quelque chose).

Rishabh_Bisht · 2024-03-07T13:04:54.052Z

@alexis_bonnyaud The error message points towards failure in resolving the domain. Are you able to perform ping/nslookup to the server domain from your host machine to this server when this error is hit? I suspect this server or your machine maybe suffering from network connectivity issues.

alexis_bonnyaud · 2024-03-07T17:03:22.709Z

Le message d’erreur apparait de temps en temps dans mes logs mais je ne l’ai jamais vécu par moi même donc je n’ai pas pu tester. Cependant j’ai quand même contacté ScaleGrid (qui gère la base de donnée) et ils m’indique n’avoir reçu aucune erreur de leur coté. Je vais essayé de mettre l’option “serverSelectionTryOnce” à false pour voir si ça change quelque chose…

Djurre_de_Boer · 2024-07-16T17:19:47.676Z

Any progress on this issue?

Hubert_Nguyen1 · 2025-02-14T19:52:42.583Z

Hi @Djurre_de_Boer , and welcome to the forums! Apologies for the long reply delay.

One of our PHP Engineer provided a response in Github on that very topic.

github.com/mongodb/mongo-php-driver

Randomly getting "socket timeout calling ismaster on"

opened 09:16AM - 12 Apr 19 UTC

closed 03:27PM - 15 Nov 19 UTC

bujardeari

### Description ``` Fatal error: Uncaught MongoDB\Driver\Exception\Connectio…nTimeoutException: No suitable servers found (`serverSelectionTryOnce` set): [socket timeout calling ismaster on 'gcp-atlas-prod-shard-00-00-gz8ag.gcp.mongodb.net:27017'] [socket timeout calling ismaster on 'gcp-atlas-prod-shard-00-01-gz8ag.gcp.mongodb.net:27017'] [socket timeout calling ismaster on 'gcp-atlas-prod-shard-00-02-gz8ag.gcp.mongodb.net:27017'] in /var/www/html/vendor/mongodb/mongodb/src/Collection.php:645 Stack trace: #0 /var/www/html/vendor/mongodb/mongodb/src/Collection.php(645): MongoDB\Driver\Manager->selectServer(Object(MongoDB\Driver\ReadPreference)) #1 /var/www/html/App/settings.php(53): MongoDB\Collection->findOne(Array) #2 /var/www/html/public/index.php(5): require_once('/var/www/html/A...') #3 {main} thrown in /var/www/html/vendor/mongodb/mongodb/src/Collection.php on line 645 ``` The problem comes randomly mostly every second time i start the pod. ### Environment I have a PHP Version 7.2.14 running on kubernetes deployment on google cloud. ``` libbson bundled version => 1.13.0 libmongoc bundled version => 1.13.0 libmongoc SSL => enabled libmongoc SSL library => OpenSSL libmongoc crypto => enabled libmongoc crypto library => libcrypto libmongoc crypto system profile => disabled libmongoc SASL => enabled libmongoc ICU => disabled libmongoc compression => enabled libmongoc compression snappy => disabled libmongoc compression zlib => enabled mongodb.debug => no value => no value ``` ``` <?php $mongo_password = "xxxxxx"; $mongo_database = "db_test"; $mongo_connectionstring = "mongodb+srv://username:".$mongo_password."@gcp-atlas-prod-gz8ag.gcp.mongodb.net"; $mongo = new MongoDB\Client($mongo_connectionstring); $collection = $mongo->$mongo_database->config; $_CFG =$collection->findOne(['id'=> 'system']); ```

The conversation is very on-point to this topic, and features details that would be too long to re-explain. Let us know if that helped and if you were able to identify a solution!