How can I solve MongoWaitQueueFullException?
I am running a java program, which is a thread executor program that inserts thousands of documents into a table in mongodb. I am getting the following error:
Exception in thread "pool-1-thread-301" com.mongodb.MongoWaitQueueFullException: Too many threads are already waiting for a connection. Max number of threads (maxWaitQueueSize) of 500 has been exceeded.
at com.mongodb.PooledConnectionProvider.get(PooledConnectionProvider.java:70)
at com.mongodb.DefaultServer.getConnection(DefaultServer.java:73)
at com.mongodb.BaseCluster$WrappedServer.getConnection(BaseCluster.java:221)
at com.mongodb.DBTCPConnector$MyPort.getConnection(DBTCPConnector.java:508)
at com.mongodb.DBTCPConnector$MyPort.get(DBTCPConnector.java:456)
at com.mongodb.DBTCPConnector.getPrimaryPort(DBTCPConnector.java:414)
at com.mongodb.DBCollectionImpl.insert(DBCollectionImpl.java:176)
at com.mongodb.DBCollectionImpl.insert(DBCollectionImpl.java:159)
at com.mongodb.DBCollection.insert(DBCollection.java:93)
at com.mongodb.DBCollection.insert(DBCollection.java:78)
at com.mongodb.DBCollection.insert(DBCollection.java:120)
at ScrapResults103$MyRunnable.run(MyProgram.java:368)
at java.util.concurrent.ThreadPoolExecutor$Worker.runTask(ThreadPoolExecutor.java:895)
at java.util.concurrent.ThreadPoolExecutor$Worker.run(ThreadPoolExecutor.java:918)
at java.lang.Thread.run(Thread.java:695)
How can I solve this? Please help me.
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2 answers
You need to check what connections per host value you specified when setting up the connection (looking at the exception, I think you would set it to 500).
MongoClientOptions.Builder builder = new MongoClientOptions.Builder();
builder.connectionsPerHost(200);
MongoClientOptions options = builder.build();
mongoClient = new MongoClient(URI, connectionOptions);
The ideal way to set up connections to a host would be trial and error, but you have to make sure that the value you set should not exceed the number of connections you can open by opening a mongo shell and running:
db.serverStatus (). Connections.available
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you are at the limit maxWaitQueueSize
, so increase the multiplier;)
MongoClientOptions options = MongoClientOptions.builder()
.threadsAllowedToBlockForConnectionMultiplier(10)
.build();
MongoClient mongo = new MongoClient("127.0.0.1:27017", options);
//run 2000 threads and use database ;)
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