feat(NODE-7142): Exponential backoff and jitter in retry loops

src/cmap/connect.ts

@@ -224,6 +224,7 @@ export interface HandshakeDocument extends Document {
   compression: string[];
   saslSupportedMechs?: string;
   loadBalanced?: boolean;
+  backpressure: true;
 }
 
 /**
@@ -241,6 +242,7 @@ export async function prepareHandshakeDocument(
 
   const handshakeDoc: HandshakeDocument = {
     [serverApi?.version || options.loadBalanced === true ? 'hello' : LEGACY_HELLO_COMMAND]: 1,
+    backpressure: true,
     helloOk: true,
     client: clientMetadata,
     compression: compressors

src/cmap/connection.ts

@@ -586,6 +586,9 @@ export class Connection extends TypedEventEmitter<ConnectionEvents> {
         this.throwIfAborted();
       }
     } catch (error) {
+      if (options.session != null && !(error instanceof MongoServerError)) {
+        updateSessionFromResponse(options.session, MongoDBResponse.empty);
+      }
       if (this.shouldEmitAndLogCommand) {
         this.emitAndLogCommand(
           this.monitorCommands,

src/index.ts

@@ -87,6 +87,7 @@ export {
   MongoWriteConcernError,
   WriteConcernErrorResult
 } from './error';
+export { TokenBucket } from './token_bucket';
 export {
   AbstractCursor,
   // Actual driver classes exported