started to write the second chapter finally

src/docbook/module/architecture.xml

@@ -5,5 +5,48 @@
 ]>
 <chapter id="architecture">
   <title>Architecture</title>
-  <para>To be written...</para>
+  <para>
+    In this chapter, we will examine what core functionalities are provided in
+    Netty and how they constitute a complete network application development
+    stack.
+  </para>
+  <section>
+    <title>Rich Buffer Data Structure</title>
+    <para>
+    
+    </para>
+  </section>
+  <section>
+    <title>Universal Asynchronous I/O API</title>
+    <para>
+      
+    </para>
+  </section>
+  
+  <section>
+    <title>Event Model based on the Interceptor Chain Pattern</title>
+    <para>
+      
+    </para>
+  </section>
+  
+  <section>
+    <title>Miscellaneous Constructs</title>
+    <para>
+    </para>
+  </section>
+
+  <section>
+    <title>A View from the Feature Set Standpoint</title>
+    <para>
+      
+    </para>
+  </section>
+
+  <section>
+    <title>Summary</title>
+    <para>
+      
+    </para>
+  </section>
 </chapter>

src/docbook/module/start.xml

@@ -12,11 +12,10 @@
     end of this chapter.
   </para>
   
-  <!-- The chapter 2 is not written yet. -->
-  <!--para>
-    If you prefer the top-down approach in learning something, you might want
-    to start from <xref linkend="architecture"/> and get back here.
-  </para-->
+  <para>
+    If you prefer top-down approach in learning something, you might want to
+    start from <xref linkend="architecture"/> and get back here.
+  </para>
   
   <section>
     <title>Before Getting Started</title>