mongodb · jyemin · Mar 31, 2025 · Mar 5, 2025 · Mar 28, 2025 · Mar 28, 2025
diff --git a/.evergreen/.evg.yml b/.evergreen/.evg.yml
@@ -285,7 +285,7 @@ functions:
           export AWS_TEMP_SESSION_TOKEN=$CSFLE_AWS_TEMP_SESSION_TOKEN
           export CRYPT_SHARED_LIB_PATH=${CRYPT_SHARED_LIB_PATH}
 
-          AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" SAFE_FOR_MULTI_MONGOS="${SAFE_FOR_MULTI_MONGOS}" TOPOLOGY="${TOPOLOGY}" \
+          AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" TOPOLOGY="${TOPOLOGY}" \
           COMPRESSOR="${COMPRESSOR}" JAVA_VERSION="${JAVA_VERSION}" REQUIRE_API_VERSION=${REQUIRE_API_VERSION} \
           TESTS="${TESTS}" .evergreen/run-tests.sh
 
@@ -344,7 +344,7 @@ functions:
         working_dir: "src"
         script: |
           ${PREPARE_SHELL}
-          SCALA="${SCALA}" AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" SAFE_FOR_MULTI_MONGOS="${SAFE_FOR_MULTI_MONGOS}" TOPOLOGY="${TOPOLOGY}" JAVA_VERSION="${JAVA_VERSION}" .evergreen/run-scala-tests.sh
+          SCALA="${SCALA}" AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" TOPOLOGY="${TOPOLOGY}" JAVA_VERSION="${JAVA_VERSION}" .evergreen/run-scala-tests.sh
 
   "run kotlin tests":
     - command: shell.exec
@@ -353,7 +353,7 @@ functions:
         working_dir: "src"
         script: |
           ${PREPARE_SHELL}
-          AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" SAFE_FOR_MULTI_MONGOS="${SAFE_FOR_MULTI_MONGOS}" TOPOLOGY="${TOPOLOGY}" JAVA_VERSION="${JAVA_VERSION}" .evergreen/run-kotlin-tests.sh
+          AUTH="${AUTH}" SSL="${SSL}" MONGODB_URI="${MONGODB_URI}" TOPOLOGY="${TOPOLOGY}" JAVA_VERSION="${JAVA_VERSION}" .evergreen/run-kotlin-tests.sh
 
 
   "run socket tests":
@@ -599,16 +599,6 @@ functions:
           LOGIN_CONTEXT_NAME=${LOGIN_CONTEXT_NAME} \
           .evergreen/run-gssapi-auth-test.sh
 
-  "run mmapv1 storage test":
-    - command: shell.exec
-      type: test
-      params:
-        silent: true
-        working_dir: "src"
-        script: |
-          ${PREPARE_SHELL}
-          PROJECT_DIRECTORY=${PROJECT_DIRECTORY} JAVA_VERSION=${JAVA_VERSION} TOPOLOGY=${TOPOLOGY} STORAGE_ENGINE=${STORAGE_ENGINE} MONGODB_URI="${MONGODB_URI}" .evergreen/run-mmapv1-storage-test.sh
-
   run socks5 tests:
     - command: shell.exec
       type: test
@@ -1577,11 +1567,6 @@ tasks:
               TEST_LAMBDA_DIRECTORY: ${PROJECT_DIRECTORY}/driver-lambda/
               AWS_REGION: us-east-1
 
-    - name: "mmapv1-storage-test"
-      commands:
-        - func: "bootstrap mongo-orchestration"
-        - func: "run mmapv1 storage test"
-
     - name: "test-kms-tls-invalid-cert"
       tags: ["kms-tls"]
       commands:
@@ -1717,55 +1702,30 @@ axes:
         display_name: "latest"
         variables:
            VERSION: "latest"
-           # Multiple mongos instances can be specified in the connection string
-           # for this version.
-           SAFE_FOR_MULTI_MONGOS: true
       - id: "8.0"
         display_name: "8.0"
         variables:
           VERSION: "8.0"
-          # Multiple mongos instances can be specified in the connection string
-          # for this version.
-          SAFE_FOR_MULTI_MONGOS: true
       - id: "7.0"
         display_name: "7.0"
         variables:
           VERSION: "7.0"
-          # Multiple mongos instances can be specified in the connection string
-          # for this version.
-          SAFE_FOR_MULTI_MONGOS: true
       - id: "6.0"
         display_name: "6.0"
         variables:
           VERSION: "6.0"
-          # Multiple mongos instances can be specified in the connection string
-          # for this version.
-          SAFE_FOR_MULTI_MONGOS: true
       - id: "5.0"
         display_name: "5.0"
         variables:
           VERSION: "5.0"
-          # Multiple mongos instances can be specified in the connection string
-          # for this version.
-          SAFE_FOR_MULTI_MONGOS: true
       - id: "4.4"
         display_name: "4.4"
         variables:
           VERSION: "4.4"
-          # Multiple mongos instances can be specified in the connection string
-          # for this version.
-          SAFE_FOR_MULTI_MONGOS: true
       - id: "4.2"
         display_name: "4.2"
         variables:
            VERSION: "4.2"
-           # Multiple mongos instances can be specified in the connection string
-           # for this version.
-           SAFE_FOR_MULTI_MONGOS: true
-      - id: "4.0"
-        display_name: "4.0"
-        variables:
-           VERSION: "4.0"
   - id: os
     display_name: OS
     values:
@@ -1886,15 +1846,6 @@ axes:
         variables:
           SCALA: "2.13"
 
-  # Choice of MongoDB storage engine
-  - id: storage-engine
-    display_name: Storage
-    values:
-      - id: mmapv1
-        display_name: MMAPv1
-        variables:
-           STORAGE_ENGINE: "mmapv1"
-
   - id: api-version
     display_name: API Version
     values:
@@ -2201,7 +2152,7 @@ buildvariants:
     - name: "test-bson-and-crypt"
 
 - matrix_name: "tests-jdk8-unsecure"
-  matrix_spec: { auth: "noauth", ssl: "nossl", jdk: "jdk8", version: ["4.0", "4.2", "4.4", "5.0", "6.0", "7.0", "8.0", "latest"],
+  matrix_spec: { auth: "noauth", ssl: "nossl", jdk: "jdk8", version: ["4.2", "4.4", "5.0", "6.0", "7.0", "8.0", "latest"],
                  topology: "*", os: "linux" }
   display_name: "${version} ${topology} ${auth} ${ssl} ${jdk} ${os} "
   tags: ["tests-variant"]
@@ -2213,7 +2164,7 @@ buildvariants:
 
 - matrix_name: "tests-jdk-secure"
   matrix_spec: { auth: "auth", ssl: "ssl", jdk: [ "jdk8", "jdk17", "jdk21"],
-                 version: ["4.0", "4.2", "4.4", "5.0", "6.0", "7.0", "8.0", "latest" ],
+                 version: ["4.2", "4.4", "5.0", "6.0", "7.0", "8.0", "latest" ],
                  topology: "*", os: "linux" }
   display_name: "${version} ${topology} ${auth} ${ssl} ${jdk} ${os} "
   tags: ["tests-variant"]
@@ -2427,12 +2378,6 @@ buildvariants:
   tasks:
     - name: "publish-release"
 
-- matrix_name: "tests-storage-engines"
-  matrix_spec: { auth: "noauth", ssl: "nossl", jdk: "jdk8", os: "linux", version: ["4.0"], topology: ["replicaset", "sharded-cluster"], storage-engine: "mmapv1" }
-  display_name: "${version} Storage ${storage-engine} ${jdk} ${os} ${topology}"
-  tasks:
-    - name: "mmapv1-storage-test"
-
 - matrix_name: "kms-tls-test"
   matrix_spec: { os: "linux", version: [ "5.0" ], topology: ["standalone"] }
   display_name: "CSFLE KMS TLS"

diff --git a/.evergreen/run-kotlin-tests.sh b/.evergreen/run-kotlin-tests.sh
@@ -8,7 +8,6 @@ AUTH=${AUTH:-noauth}
 SSL=${SSL:-nossl}
 MONGODB_URI=${MONGODB_URI:-}
 TOPOLOGY=${TOPOLOGY:-standalone}
-SAFE_FOR_MULTI_MONGOS=${SAFE_FOR_MULTI_MONGOS:-}
 
 ############################################
 #            Main Program                  #
@@ -27,9 +26,7 @@ if [ "$AUTH" != "noauth" ]; then
   exit 1
 fi
 
-if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-    export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MONGODB_URI}"
-fi
+export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MONGODB_URI}"
 
 ./gradlew -version
 

diff --git a/.evergreen/run-mmapv1-storage-test.sh b/.evergreen/run-mmapv1-storage-test.sh
diff --git a/.evergreen/run-scala-tests.sh b/.evergreen/run-scala-tests.sh
@@ -8,7 +8,6 @@ AUTH=${AUTH:-noauth}
 SSL=${SSL:-nossl}
 MONGODB_URI=${MONGODB_URI:-}
 TOPOLOGY=${TOPOLOGY:-standalone}
-SAFE_FOR_MULTI_MONGOS=${SAFE_FOR_MULTI_MONGOS:-}
 
 ############################################
 #            Main Program                  #
@@ -27,9 +26,7 @@ if [ "$AUTH" != "noauth" ]; then
   exit 1
 fi
 
-if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-    export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MONGODB_URI}"
-fi
+export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MONGODB_URI}"
 
 echo "Running scala tests with Scala $SCALA"
 

diff --git a/.evergreen/run-tests.sh b/.evergreen/run-tests.sh
@@ -68,14 +68,10 @@ provision_multi_mongos_uri_for_ssl () {
   # Arguments for auth + SSL
   if [ "$AUTH" != "noauth" ] || [ "$TOPOLOGY" == "replica_set" ]; then
     export MONGODB_URI="${MONGODB_URI}&ssl=true&sslInvalidHostNameAllowed=true"
-    if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-        export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}&ssl=true&sslInvalidHostNameAllowed=true"
-    fi
+    export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}&ssl=true&sslInvalidHostNameAllowed=true"
   else
     export MONGODB_URI="${MONGODB_URI}/?ssl=true&sslInvalidHostNameAllowed=true"
-    if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-        export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}/?ssl=true&sslInvalidHostNameAllowed=true"
-    fi
+    export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}/?ssl=true&sslInvalidHostNameAllowed=true"
   fi
 }
 
@@ -85,13 +81,11 @@ provision_multi_mongos_uri_for_ssl () {
 
 # Provision the correct connection string and set up SSL if needed
 if [ "$TOPOLOGY" == "sharded_cluster" ]; then
-    if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-        if [ "$AUTH" = "auth" ]; then
-            export MULTI_MONGOS_URI="mongodb://bob:pwd123@localhost:27017,localhost:27018/?authSource=admin"
-        else
-            export MULTI_MONGOS_URI="${MONGODB_URI}"
-        fi
-    fi
+     if [ "$AUTH" = "auth" ]; then
+       export MULTI_MONGOS_URI="mongodb://bob:pwd123@localhost:27017,localhost:27018/?authSource=admin"
+     else
+       export MULTI_MONGOS_URI="${MONGODB_URI}"
+     fi
 
      if [ "$AUTH" = "auth" ]; then
        export MONGODB_URI="mongodb://bob:pwd123@localhost:27017/?authSource=admin"
@@ -107,12 +101,10 @@ if [ "$COMPRESSOR" != "" ]; then
        export MONGODB_URI="${MONGODB_URI}/?compressors=${COMPRESSOR}"
      fi
 
-     if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-         if [[ "$MULTI_MONGOS_URI" == *"?"* ]]; then
-             export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}&compressors=${COMPRESSOR}"
-         else
-             export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}/?compressors=${COMPRESSOR}"
-         fi
+     if [[ "$MULTI_MONGOS_URI" == *"?"* ]]; then
+       export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}&compressors=${COMPRESSOR}"
+     else
+       export MULTI_MONGOS_URI="${MULTI_MONGOS_URI}/?compressors=${COMPRESSOR}"
      fi
 fi
 
@@ -123,9 +115,7 @@ if [ "$SSL" != "nossl" ]; then
    provision_multi_mongos_uri_for_ssl
 fi
 
-if [ "$SAFE_FOR_MULTI_MONGOS" == "true" ]; then
-    export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MULTI_MONGOS_URI}"
-fi
+export MULTI_MONGOS_URI_SYSTEM_PROPERTY="-Dorg.mongodb.test.multi.mongos.uri=${MULTI_MONGOS_URI}"
 
 # For now it's sufficient to hard-code the API version to "1", since it's the only API version
 if [ ! -z "$REQUIRE_API_VERSION" ]; then

diff --git a/driver-core/src/main/com/mongodb/connection/ConnectionDescription.java b/driver-core/src/main/com/mongodb/connection/ConnectionDescription.java
@@ -29,6 +29,7 @@
 
 import static com.mongodb.assertions.Assertions.notNull;
 import static com.mongodb.connection.ServerDescription.getDefaultMaxDocumentSize;
+import static com.mongodb.internal.operation.ServerVersionHelper.UNKNOWN_WIRE_VERSION;
 
 /**
  * A description of a connection to a MongoDB server.
@@ -57,7 +58,7 @@ public class ConnectionDescription {
      * @param serverId   the server address
      */
     public ConnectionDescription(final ServerId serverId) {
-        this(new ConnectionId(serverId), 0, ServerType.UNKNOWN, DEFAULT_MAX_WRITE_BATCH_SIZE,
+        this(new ConnectionId(serverId), UNKNOWN_WIRE_VERSION, ServerType.UNKNOWN, DEFAULT_MAX_WRITE_BATCH_SIZE,
              getDefaultMaxDocumentSize(), DEFAULT_MAX_MESSAGE_SIZE, Collections.emptyList());
     }
 

diff --git a/driver-core/src/main/com/mongodb/connection/ServerDescription.java b/driver-core/src/main/com/mongodb/connection/ServerDescription.java
@@ -55,12 +55,12 @@ public class ServerDescription {
      * The minimum supported driver server version
      * @since 3.8
      */
-    public static final String MIN_DRIVER_SERVER_VERSION = "3.6";
+    public static final String MIN_DRIVER_SERVER_VERSION = "4.2";
     /**
      * The minimum supported driver wire version
      * @since 3.8
      */
-    public static final int MIN_DRIVER_WIRE_VERSION = 7;
+    public static final int MIN_DRIVER_WIRE_VERSION = 8;
     /**
      * The maximum supported driver wire version
      * @since 3.8

diff --git a/driver-core/src/main/com/mongodb/internal/connection/CommandMessage.java b/driver-core/src/main/com/mongodb/internal/connection/CommandMessage.java
@@ -60,8 +60,7 @@
 import static com.mongodb.internal.connection.ByteBufBsonDocument.createList;
 import static com.mongodb.internal.connection.ByteBufBsonDocument.createOne;
 import static com.mongodb.internal.connection.ReadConcernHelper.getReadConcernDocument;
-import static com.mongodb.internal.operation.ServerVersionHelper.FOUR_DOT_TWO_WIRE_VERSION;
-import static com.mongodb.internal.operation.ServerVersionHelper.FOUR_DOT_ZERO_WIRE_VERSION;
+import static com.mongodb.internal.operation.ServerVersionHelper.UNKNOWN_WIRE_VERSION;
 
 /**
  * A command message that uses OP_MSG or OP_QUERY to send the command.
@@ -346,7 +345,6 @@ private List<BsonElement> getExtraElements(final OperationContext operationConte
 
         assertFalse(sessionContext.hasActiveTransaction() && sessionContext.isSnapshot());
         if (sessionContext.hasActiveTransaction()) {
-            checkServerVersionForTransactionSupport();
             extraElements.add(new BsonElement("txnNumber", new BsonInt64(sessionContext.getTransactionNumber())));
             if (firstMessageInTransaction) {
                 extraElements.add(new BsonElement("startTransaction", BsonBoolean.TRUE));
@@ -381,12 +379,6 @@ private void addServerApiElements(final List<BsonElement> extraElements) {
         }
     }
 
-    private void checkServerVersionForTransactionSupport() {
-        if (getSettings().getMaxWireVersion() < FOUR_DOT_TWO_WIRE_VERSION && getSettings().getServerType() == SHARD_ROUTER) {
-            throw new MongoClientException("Transactions are not supported by the MongoDB cluster to which this client is connected.");
-        }
-    }
-
 
     private void addReadConcernDocument(final List<BsonElement> extraElements, final SessionContext sessionContext) {
         BsonDocument readConcernDocument = getReadConcernDocument(sessionContext, getSettings().getMaxWireVersion());
@@ -416,7 +408,7 @@ private static OpCode getOpCode(final MessageSettings settings, final ClusterCon
     }
 
     private static boolean isServerVersionKnown(final MessageSettings settings) {
-        return settings.getMaxWireVersion() >= FOUR_DOT_ZERO_WIRE_VERSION;
+        return settings.getMaxWireVersion() != UNKNOWN_WIRE_VERSION;
     }
 
     @FunctionalInterface

diff --git a/...er-core/src/main/com/mongodb/internal/connection/DefaultSdamServerDescriptionManager.java b/...er-core/src/main/com/mongodb/internal/connection/DefaultSdamServerDescriptionManager.java
@@ -119,7 +119,7 @@ private void handleException(final SdamIssue sdamIssue, final boolean beforeHand
         }
         if (sdamIssue.relatedToStateChange()) {
             updateDescription(sdamIssue.serverDescription());
-            if (sdamIssue.serverIsLessThanVersionFourDotTwo() || sdamIssue.relatedToShutdown()) {
+            if (sdamIssue.relatedToShutdown()) {
                 connectionPool.invalidate(sdamIssue.exception().orElse(null));
             }
             serverMonitor.connect();
@@ -130,9 +130,6 @@ private void handleException(final SdamIssue sdamIssue, final boolean beforeHand
             serverMonitor.cancelCurrentCheck();
         } else if (sdamIssue.relatedToWriteConcern() || !sdamIssue.specific()) {
             updateDescription(sdamIssue.serverDescription());
-            if (sdamIssue.serverIsLessThanVersionFourDotTwo()) {
-                connectionPool.invalidate(sdamIssue.exception().orElse(null));
-            }
             serverMonitor.connect();
         }
     }

diff --git a/driver-core/src/main/com/mongodb/internal/connection/MessageSettings.java b/driver-core/src/main/com/mongodb/internal/connection/MessageSettings.java
@@ -20,6 +20,8 @@
 import com.mongodb.annotations.NotThreadSafe;
 import com.mongodb.connection.ServerType;
 
+import static com.mongodb.internal.operation.ServerVersionHelper.UNKNOWN_WIRE_VERSION;
+
 /**
  * The message settings
  *
@@ -75,7 +77,7 @@ public static final class Builder {
         private int maxDocumentSize = DEFAULT_MAX_DOCUMENT_SIZE;
         private int maxMessageSize = DEFAULT_MAX_MESSAGE_SIZE;
         private int maxBatchCount = DEFAULT_MAX_BATCH_COUNT;
-        private int maxWireVersion;
+        private int maxWireVersion = UNKNOWN_WIRE_VERSION;
         private ServerType serverType;
         private boolean sessionSupported;
         private boolean cryptd;