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Type: Question
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Resolution: Works as Designed
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Priority: Major - P3
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None
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Affects Version/s: None
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Component/s: Transaction Management
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(copied to CRM)
When using the ClientSession.withTransaction helper the MongoClient's serverSelectionTimeout value is not respected.
This same behavior does not happen if the transaction is manually created using ClientSession.startTransaction() and committed using ClientSession.commitTransaction
# setup
mlaunch init --replicaset --nodes 3 --hostname 192.168.2.13 --bind_ip_all --binarypath $(m bin 5.0.5-ent)
<?xml version="1.0" encoding="UTF-8"?> <project xmlns="http://maven.apache.org/POM/4.0.0" xmlns:xsi="http://www.w3.org/2001/XMLSchema-instance" xsi:schemaLocation="http://maven.apache.org/POM/4.0.0 http://maven.apache.org/xsd/maven-4.0.0.xsd"> <modelVersion>4.0.0</modelVersion> <groupId>com.example</groupId> <artifactId>demo</artifactId> <version>1.0-SNAPSHOT</version> <name>demo</name> <!-- FIXME change it to the project's website --> <url>http://www.example.com</url> <properties> <project.build.sourceEncoding>UTF-8</project.build.sourceEncoding> <maven.compiler.source>1.8</maven.compiler.source> <maven.compiler.target>1.8</maven.compiler.target> </properties> <dependencies> <dependency> <groupId>org.mongodb</groupId> <artifactId>mongodb-driver-sync</artifactId> <version>4.4.0</version> </dependency> </dependencies> <build> <pluginManagement> <!-- lock down plugins versions to avoid using Maven defaults (may be moved to parent pom) --> <plugins> <!-- clean lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#clean_Lifecycle --> <plugin> <artifactId>maven-clean-plugin</artifactId> <version>3.1.0</version> </plugin> <!-- default lifecycle, jar packaging: see https://maven.apache.org/ref/current/maven-core/default-bindings.html#Plugin_bindings_for_jar_packaging --> <plugin> <artifactId>maven-resources-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-compiler-plugin</artifactId> <version>3.8.0</version> </plugin> <plugin> <artifactId>maven-surefire-plugin</artifactId> <version>2.22.1</version> </plugin> <plugin> <artifactId>maven-jar-plugin</artifactId> <version>3.0.2</version> </plugin> <plugin> <artifactId>maven-install-plugin</artifactId> <version>2.5.2</version> </plugin> <plugin> <artifactId>maven-deploy-plugin</artifactId> <version>2.8.2</version> </plugin> <!-- site lifecycle, see https://maven.apache.org/ref/current/maven-core/lifecycles.html#site_Lifecycle --> <plugin> <artifactId>maven-site-plugin</artifactId> <version>3.7.1</version> </plugin> <plugin> <artifactId>maven-project-info-reports-plugin</artifactId> <version>3.0.0</version> </plugin> </plugins> </pluginManagement> </build> </project>
package com.example; import java.util.ArrayList; import java.util.List; import java.util.logging.Logger; import com.mongodb.connection.ClusterDescription; import com.mongodb.connection.ServerDescription; import com.mongodb.selector.ServerSelector; public class EmptyServerSelector implements ServerSelector { private static Logger LOGGER = null; static { System.setProperty("java.util.logging.SimpleFormatter.format", "[%1$tF %1$tT] [%4$-7s] %5$s %n"); LOGGER = Logger.getLogger(EmptyServerSelector.class.getName()); } @Override public List<ServerDescription> select(ClusterDescription clusterDescription) { LOGGER.info("Returning empty list of server descriptions"); return new ArrayList<>(); } }
package com.example; import java.util.Arrays; import java.util.List; import java.util.concurrent.TimeUnit; import com.mongodb.*; import com.mongodb.client.*; import com.mongodb.client.result.UpdateResult; import org.bson.Document; import org.bson.conversions.Bson; import static com.mongodb.client.model.Updates.inc; import static com.mongodb.client.model.Filters.*; public class ServerSelectionTxnLoopTest { private static Bson _filter = eq("_id", 1); private static Bson _update = inc("items.$.quantity", 2); private static MongoCollection<Document> _coll; private static void usingManualTransaction(ClientSession session) { session.startTransaction(TransactionOptions.builder().writeConcern(WriteConcern.MAJORITY).build()); _coll.updateOne(session, _filter, _update); session.commitTransaction(); } private static void usingWithTransaction(ClientSession session) { TransactionBody<UpdateResult> txnUpdateBody = () -> _coll.updateOne(session, _filter, _update); session.withTransaction(txnUpdateBody); } public static void main(final String[] args) { List<ServerAddress> hosts = Arrays.asList( new ServerAddress("192.168.2.13:27017"), new ServerAddress("192.168.2.13:27018"), new ServerAddress("192.168.2.13:27019")); MongoClient client = MongoClients.create( MongoClientSettings.builder() .applyToClusterSettings(builder -> builder .hosts(hosts) .serverSelector(new EmptyServerSelector()) .serverSelectionTimeout(2, TimeUnit.SECONDS)) .build()); System.out.println("MongoClient created with a serverSelectionTimeout of 2 seconds"); MongoDatabase db = client.getDatabase("test"); _coll = db.getCollection("foo"); ClientSession session = client.startSession(); try { // usingManualTransaction(session); // this one will work usingWithTransaction(session); // this one will FAIL } catch (MongoCommandException | MongoWriteException e) { session.abortTransaction(); } finally { session.close(); } } }
If the above code is run with usingManualTransaction(session) uncommented, the application will exit with a MongoTimeoutException being raised after 2 seconds (as expected)
MongoClient created with a serverSelectionTimeout of 2 seconds [2022-01-26 14:54:05] [INFO ] Returning empty list of server descriptions ... [2022-01-26 14:54:07] [INFO ] Returning empty list of server descriptions Exception in thread "main" com.mongodb.MongoTimeoutException: Timed out after 2000 ms while waiting for a server that matches WritableServerSelector. Client view of cluster state is {type=SHARDED, servers=[{address=192.168.2.13:27019, type=SHARD_ROUTER, roundTripTime=34.5 ms, state=CONNECTED}, {address=192.168.2.13:27017, type=SHARD_ROUTER, roundTripTime=32.0 ms, state=CONNECTED}, {address=192.168.2.13:27018, type=SHARD_ROUTER, roundTripTime=34.8 ms, state=CONNECTED}] at com.mongodb.internal.connection.BaseCluster.createTimeoutException(BaseCluster.java:414) at com.mongodb.internal.connection.BaseCluster.selectServer(BaseCluster.java:122) at com.mongodb.internal.connection.AbstractMultiServerCluster.selectServer(AbstractMultiServerCluster.java:50) at com.mongodb.internal.binding.ClusterBinding.getWriteConnectionSource(ClusterBinding.java:128) at com.mongodb.client.internal.ClientSessionBinding.getPinnedConnectionSource(ClientSessionBinding.java:133) at com.mongodb.client.internal.ClientSessionBinding.getWriteConnectionSource(ClientSessionBinding.java:102) at com.mongodb.internal.operation.OperationHelper.withSuppliedResource(OperationHelper.java:581) at com.mongodb.internal.operation.OperationHelper.withSourceAndConnection(OperationHelper.java:562) at com.mongodb.internal.operation.MixedBulkWriteOperation.lambda$execute$3(MixedBulkWriteOperation.java:232) at com.mongodb.internal.async.function.RetryingSyncSupplier.get(RetryingSyncSupplier.java:65) at com.mongodb.internal.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:268) at com.mongodb.internal.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:84) at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:212) at com.mongodb.client.internal.MongoCollectionImpl.executeSingleWriteRequest(MongoCollectionImpl.java:1010) at com.mongodb.client.internal.MongoCollectionImpl.executeUpdate(MongoCollectionImpl.java:994) at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:591) at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:584) at com.example.App.usingManualTransaction(App.java:24) at com.example.App.main(App.java:54)
If however this is run with the usingWithTransaction(session) call uncommented the application will loop for 2 minutes and then exit, though the MongoTimeoutException that is thrown indicates the configured 2 second value:
MongoClient created with a serverSelectionTimeout of 2 seconds [2022-01-26 14:07:53] [INFO ] Returning empty list of server descriptions ... [2022-01-26 14:09:54] [INFO ] Returning empty list of server descriptions Exception in thread "main" com.mongodb.MongoTimeoutException: Timed out after 2000 ms while waiting for a server that matches WritableServerSelector. Client view of cluster state is {type=SHARDED, servers=[{address=192.168.2.13:27019, type=SHARD_ROUTER, roundTripTime=7.7 ms, state=CONNECTED}, {address=192.168.2.13:27017, type=SHARD_ROUTER, roundTripTime=7.7 ms, state=CONNECTED}, {address=192.168.2.13:27018, type=SHARD_ROUTER, roundTripTime=7.6 ms, state=CONNECTED}] at com.mongodb.internal.connection.BaseCluster.createTimeoutException(BaseCluster.java:414) at com.mongodb.internal.connection.BaseCluster.selectServer(BaseCluster.java:122) at com.mongodb.internal.connection.AbstractMultiServerCluster.selectServer(AbstractMultiServerCluster.java:50) at com.mongodb.internal.binding.ClusterBinding.getWriteConnectionSource(ClusterBinding.java:128) at com.mongodb.client.internal.ClientSessionBinding.getPinnedConnectionSource(ClientSessionBinding.java:133) at com.mongodb.client.internal.ClientSessionBinding.getWriteConnectionSource(ClientSessionBinding.java:102) at com.mongodb.internal.operation.OperationHelper.withSuppliedResource(OperationHelper.java:581) at com.mongodb.internal.operation.OperationHelper.withSourceAndConnection(OperationHelper.java:562) at com.mongodb.internal.operation.MixedBulkWriteOperation.lambda$execute$3(MixedBulkWriteOperation.java:232) at com.mongodb.internal.async.function.RetryingSyncSupplier.get(RetryingSyncSupplier.java:65) at com.mongodb.internal.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:268) at com.mongodb.internal.operation.MixedBulkWriteOperation.execute(MixedBulkWriteOperation.java:84) at com.mongodb.client.internal.MongoClientDelegate$DelegateOperationExecutor.execute(MongoClientDelegate.java:212) at com.mongodb.client.internal.MongoCollectionImpl.executeSingleWriteRequest(MongoCollectionImpl.java:1010) at com.mongodb.client.internal.MongoCollectionImpl.executeUpdate(MongoCollectionImpl.java:994) at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:591) at com.mongodb.client.internal.MongoCollectionImpl.updateOne(MongoCollectionImpl.java:584) at com.example.App.lambda$0(App.java:29) at com.mongodb.client.internal.ClientSessionImpl.withTransaction(ClientSessionImpl.java:211) at com.mongodb.client.internal.ClientSessionImpl.withTransaction(ClientSessionImpl.java:199) at com.example.App.usingWithTransaction(App.java:30) at com.example.App.main(App.java:55)
- is related to
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DRIVERS-2185 withTransaction should not retry after server selection timeout errors
- Backlog