increasing max http header size from 8192 to 32768

sdk/src/main/java/com/microsoft/azure/cosmosdb/rx/internal/RxDocumentClientImpl.java

@@ -115,8 +115,15 @@
 import io.reactivex.netty.channel.SingleNioLoopProvider;
 import io.reactivex.netty.client.RxClient;
 import io.reactivex.netty.pipeline.ssl.SSLEngineFactory;
+import io.reactivex.netty.pipeline.PipelineConfigurator;
+import io.reactivex.netty.pipeline.PipelineConfiguratorComposite;
+import io.reactivex.netty.protocol.http.HttpObjectAggregationConfigurator;
 import io.reactivex.netty.protocol.http.client.CompositeHttpClient;
 import io.reactivex.netty.protocol.http.client.CompositeHttpClientBuilder;
+import io.reactivex.netty.protocol.http.client.HttpClientPipelineConfigurator;
+import io.reactivex.netty.protocol.http.client.HttpClientRequest;
+import io.reactivex.netty.protocol.http.client.HttpClientResponse;
+
 import rx.Observable;
 import rx.Single;
 import rx.functions.Func1;
@@ -231,13 +238,22 @@ public SSLEngine createSSLEngine(ByteBufAllocator allocator) {
         CompositeHttpClientBuilder<ByteBuf, ByteBuf> builder = new CompositeHttpClientBuilder<ByteBuf, ByteBuf>()
                 .withSslEngineFactory(new DefaultSSLEngineFactory())
                 .withMaxConnections(connectionPolicy.getMaxPoolSize())
-                .withIdleConnectionsTimeoutMillis(this.connectionPolicy.getIdleConnectionTimeoutInMillis());
+                .withIdleConnectionsTimeoutMillis(this.connectionPolicy.getIdleConnectionTimeoutInMillis())
+                .pipelineConfigurator(createClientPipelineConfigurator());
 
         RxClient.ClientConfig config = new RxClient.ClientConfig.Builder()
                 .readTimeout(connectionPolicy.getRequestTimeoutInMillis(), TimeUnit.MILLISECONDS).build();
         return builder.config(config);
     }
 
+    private PipelineConfigurator createClientPipelineConfigurator() {
+        PipelineConfigurator clientPipelineConfigurator = new PipelineConfiguratorComposite<HttpClientResponse<ByteBuf>,
+                HttpClientRequest<ByteBuf>>(new HttpClientPipelineConfigurator<ByteBuf, ByteBuf>
+                (8192, 32768, 8182, true ),
+                new HttpObjectAggregationConfigurator());
+        return clientPipelineConfigurator;
+    }
+
     @Override
     public URI getServiceEndpoint() {
         return this.serviceEndpoint;