How to connect to Atlas M0 (Free Tier) cluster correctly via Java driver?

Question

Trying to connect Atlas cluster via Java driver using MongoDB version 3.6.

So, I'm writting like:

 MongoClientURI uri = new MongoClientURI("mongodb+srv://admin:[email protected]/test?retryWrites=true");
 MongoClient mongoClient = new MongoClient(uri);

In this case the error is:

java.lang.IllegalArgumentException: The connection string is invalid. Connection strings must start with 'mongodb://'
    at com.mongodb.ConnectionString.<init>(ConnectionString.java:203)
    at com.mongodb.MongoClientURI.<init>(MongoClientURI.java:176)
    at com.mongodb.MongoClientURI.<init>(MongoClientURI.java:158)
    at project.Bot.check(Bot.java:30)
    at project.Bot.onUpdateReceived(Bot.java:104)
    at java.util.ArrayList.forEach(ArrayList.java:1249)
    at org.telegram.telegrambots.generics.LongPollingBot.onUpdatesReceived(LongPollingBot.java:27)
    at org.telegram.telegrambots.updatesreceivers.DefaultBotSession$HandlerThread.run(DefaultBotSession.java:309)

When the program starts with snippet using MongoDB version 3.6 or later without +srv:

MongoClientURI uri = new MongoClientURI("mongodb://admin1:[email protected]/test?retryWrites=true");
MongoClient mongoClient = new MongoClient(uri);

I'm getting an error:

com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting for a server that matches ReadPreferenceServerSelector{readPreference=primary}. Client view of cluster state is {type=UNKNOWN, servers=[{address=cluster0.mongodb.net:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketException: cluster0.mongodb.net}, caused by {java.net.UnknownHostException: cluster0.mongodb.net}}]
    at com.mongodb.connection.BaseCluster.createTimeoutException(BaseCluster.java:369)
    at com.mongodb.connection.BaseCluster.selectServer(BaseCluster.java:101)
    at com.mongodb.binding.ClusterBinding$ClusterBindingConnectionSource.<init>(ClusterBinding.java:75)
    at com.mongodb.binding.ClusterBinding$ClusterBindingConnectionSource.<init>(ClusterBinding.java:71)
    at com.mongodb.binding.ClusterBinding.getReadConnectionSource(ClusterBinding.java:63)
    at com.mongodb.operation.OperationHelper.withConnection(OperationHelper.java:201)
    at com.mongodb.operation.CountOperation.execute(CountOperation.java:206)
    at com.mongodb.operation.CountOperation.execute(CountOperation.java:53)
    at com.mongodb.Mongo.execute(Mongo.java:772)
    at com.mongodb.Mongo$2.execute(Mongo.java:759)
    at com.mongodb.MongoCollectionImpl.count(MongoCollectionImpl.java:185)
    at com.mongodb.MongoCollectionImpl.count(MongoCollectionImpl.java:170)
    at project.Bot.check(Bot.java:36)
    at project.Bot.onUpdateReceived(Bot.java:103)
    at java.util.ArrayList.forEach(ArrayList.java:1249)
    at org.telegram.telegrambots.generics.LongPollingBot.onUpdatesReceived(LongPollingBot.java:27)
    at org.telegram.telegrambots.updatesreceivers.DefaultBotSession$HandlerThread.run(DefaultBotSession.java:309)

In POM file I have dependency:

        <dependency>
            <groupId>org.mongodb</groupId>
            <artifactId>mongo-java-driver</artifactId>
            <version>3.6.0</version>
        </dependency>

Also, when I'm starting mongo my database is added to this address mongodb://127.0.0.1:27017, but I added path to the cluster not for this. Maybe I need to write path to concrete cluster or?

Ofc, I have admin-user. In addition, I can connect via Compass to my cluster and from shell. mongod process is started. This error appears only, when I'm running in IDE. Same issue probably here.

Does anyone know how to solve this error? I appreciate any help.

Answer 1

Solved it! So, what I've done:

1. I tried only to connect to tier cluster via driver3.6 and wrote

   mongodb+srv://user:@cluster0-ox90k.mongodb.net/test?retryWrites=true

I always get an error: Connection strings must start with 'mongodb://'.

2. Okay, I deleted the snippet +srv and wrote the same way

   mongodb://user:@cluster0-ox90k.mongodb.net/test?retryWrites=true

and get again the error:

com.mongodb.MongoTimeoutException: Timed out after 30000 ms while waiting for a server that matches ReadPreferenceServerSelector{readPreference=primary}. Client view of cluster state is {type=UNKNOWN, servers=[{address=cluster0-ox90k.mongodb.net:27017, type=UNKNOWN, state=CONNECTING, exception={com.mongodb.MongoSocketException: cluster0-ox90k.mongodb.net}, caused by {java.net.UnknownHostException: cluster0-ox90k.mongodb.net}}]

So, I wrote via driver3.4 or earlier like

mongodb://user:<PASSWORD>@cluster0-shard-00-00-ox90k.mongodb.net:27017,cluster0-shard-00-01-ox90k.mongodb.net:27017,cluster0-shard-00-02-ox90k.mongodb.net:27017/test?ssl=true&replicaSet=Cluster0-shard-0&authSource=admin&retryWrites=true

and finally it solved.

Note: You can get this connection string from the Atlas management console by setting your Java driver to '3.4 or later'. This will help you avoid having to come up with the connection string yourself.

---

Updated: if you want to use drivers 3.7+, you need to write instead of format connection (and to avoid my issues above)

MongoClientURI uri = new MongoClientURI("mongodb+srv://admin:[email protected]/test?retryWrites=true");
MongoClient mongoClient = new MongoClient(uri);

another variant using MongoClients.create() (as of the 3.7 release), and as mentioned here:

   MongoClient mongoClient = MongoClients.create("mongodb+srv://admin:[email protected]/test?retryWrites=true");

Note: the password need to write not like mongodb://user:<mypassword>@...,

just in format mongodb://user:mypassword@...

without braces <>.

Answer 2

There seem to be a few issues here

First

3.6.0 is not the Mongo driver library that was actually loaded into your application classpath; I suspect that you were previously testing with an old version, and recently updated the POM? You were previously using version 3.2.0.

How do I know this?

I started digging through the code, and at version 3.6.0, the error message you provided is nowhere near line 203. And also, you can see that the above linked code has support for the +srv.

Browing back through previousl releases, I finally found that error massge on line 203, back at release 3.2.0.

Long story short, trying doing a Maven clean, and rebuild.

Relaunch Eclipse to pick up new dependencies if a project refresh does not help.

Second

MongoTimeoutException: Timed out after 30000 ms while waiting for a server

This one is highly likely a firewall / access control group configuration issue, in that the firewall is blocking the packets from reaching your Atlas cluster.

See adding addresses to the whitelist.