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       <title>WildFly + Axis2 HTTP/2 Integration Guide</title>
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    <body>

<h1>WildFly + Axis2 HTTP/2 Integration Guide</h1>

<p><strong>Tested on:</strong> WildFly 32 (OpenJDK 17, 21) and WildFly 39
(OpenJDK 21, 25). Configuration examples below use WildFly 32 syntax;
WildFly 39 is compatible with the same configuration.</p>

<div style="background-color: #ffe8e8; border: 1px solid #ff4444; padding: 10px; margin: 10px 0;">

<h4>H2TransportSender Configuration (Simplified with Intelligent Defaults)</h4>

<pre>
&lt;!-- Minimal HTTP/2 Transport - Intelligent Defaults Handle Optimization --&gt;
&lt;transportSender name="http" class="org.apache.axis2.transport.h2.impl.httpclient5.H2TransportSender"&gt;
    &lt;parameter name="PROTOCOL"&gt;HTTP/2.0&lt;/parameter&gt;
&lt;/transportSender&gt;
</pre>

</div>

<h2>WildFly Server-Level HTTP/2 Configuration (RECOMMENDED)</h2>

<div style="background-color: #e8f5e8; border: 1px solid #4CAF50; padding: 10px; margin: 10px 0;">
<strong>Key Optimizations:</strong>
<ul>
  <li><strong>64KB Buffer/Flush Alignment</strong> - WildFly byte-buffer-pool and FlushingOutputStream flush interval are aligned at 64KB. This is a server-side serialization setting and is correct.</li>
  <li><strong>HTTP/2 Flow-Control Windows</strong> - Sized for payload, not aligned to flush interval. See
      <a href="http2-transport-additions.html#H2TransportSender">HTTP/2 Transport configuration</a>
      for guidance on <code>initialWindowSize</code> tuning.</li>
  <li><strong>Minimal Protocol Overhead</strong> - Single-layer HTTP/2 processing architecture</li>
  <li><strong>Enhanced Monitoring</strong> - Built-in performance tracking and access logging</li>
</ul>
</div>

<div style="background-color: #fff8e1; border: 1px solid #f9a825; padding: 10px; margin: 10px 0;">
<strong>Important:</strong> The Axis2 transport's
<code>initialWindowSize</code> should <strong>not</strong> be set to
64KB to match the WildFly buffer pool or FlushingOutputStream flush
interval. The flow-control window and the server-side flush interval are
independent — a 64KB window forces ~156 WINDOW_UPDATE round-trips for a
10MB response. Use at least 2MB for general traffic or 8MB for
large-payload workloads. See
<a href="http2-transport-additions.html#H2TransportSender">HTTP/2 Transport
— Tuning for Different Workloads</a>.
</div>

<pre>
&lt;subsystem xmlns="urn:jboss:domain:undertow:14.0"
           default-virtual-host="default-host"
           default-servlet-container="default"
           default-server="default-server"
           statistics-enabled="${wildfly.undertow.statistics-enabled:${wildfly.statistics-enabled:false}}"
           default-security-domain="other"&gt;

    &lt;!-- MINIMAL WILDFLY HTTP/2 - Optimized Buffer Pool Configuration --&gt;
    &lt;!-- Aligned with Enhanced Moshi H2 processing (64KB standard across all layers) --&gt;
    &lt;!-- Reduces buffer fragmentation and improves memory efficiency --&gt;
    &lt;byte-buffer-pool name="default" buffer-size="65536" max-pool-size="512" direct="true"/&gt;

    &lt;!-- Single-Layer Buffer Cache - Optimized for JSON Processing --&gt;
    &lt;!-- Aligned 64KB cache for consistent buffer management --&gt;
    &lt;buffer-cache name="default" buffer-size="65536" buffers-per-region="64"/&gt;

    &lt;server name="default-server"&gt;
        &lt;!-- MINIMAL WILDFLY HTTP/2 - Optimized for Single-Layer Processing --&gt;
        &lt;!-- Reduced protocol overhead, optimized for Enhanced Moshi H2 JSON processing --&gt;
        &lt;http-listener name="default" socket-binding="http"
                       max-post-size="104857600"
                       redirect-socket="https"
                       enable-http2="true"
                       http2-enable-push="false"
                       http2-header-table-size="8192"
                       http2-initial-window-size="2097152"
                       http2-max-concurrent-streams="75"
                       http2-max-frame-size="65536"
                       http2-max-header-list-size="32768"
                       max-connections="150"
                       receive-buffer="4194304"
                       send-buffer="2097152"
                       no-request-timeout="300000"
                       request-parse-timeout="60000"
                       tcp-backlog="1024"/&gt;

        &lt;!-- MINIMAL WILDFLY HTTP/2 HTTPS - Aligned with HTTP configuration --&gt;
        &lt;!-- SSL-optimized single-layer HTTP/2 processing --&gt;
        &lt;https-listener name="https" socket-binding="https"
                        max-post-size="104857600"
                        ssl-context="applicationSSC"
                        enable-http2="true"
                        http2-enable-push="false"
                        http2-header-table-size="8192"
                        http2-initial-window-size="2097152"
                        http2-max-concurrent-streams="75"
                        http2-max-frame-size="65536"
                        http2-max-header-list-size="32768"
                        max-connections="150"
                        receive-buffer="4194304"
                        send-buffer="2097152"
                        no-request-timeout="300000"
                        request-parse-timeout="60000"
                        tcp-backlog="1024"/&gt;

        &lt;host name="default-host" alias="localhost"&gt;
            &lt;!-- Enhanced Access Log for HTTP/2 Performance Monitoring --&gt;
            &lt;access-log pattern="%h %l %u %t &quot;%r&quot; %s %b &quot;%{i,Referer}&quot; &quot;%{i,User-Agent}&quot; Cookie: &quot;%{i,COOKIE}&quot; Set-Cookie: &quot;%{o,SET-COOKIE}&quot; SessionID: %S Thread: &quot;%I&quot; TimeTaken: %T Protocol: %H Bytes: %B"/&gt;

            &lt;!-- HTTP/2 Performance Optimization Filters --&gt;
            &lt;filter-ref name="gzip-compression"/&gt;
            &lt;filter-ref name="cache-control-headers"/&gt;
        &lt;/host&gt;
    &lt;/server&gt;

    &lt;!-- HTTP/2 Optimization Filters --&gt;
    &lt;filters&gt;
        &lt;!-- JSON compression for JSON-RPC / REST operations (30-50% reduction) --&gt;
        &lt;gzip name="gzip-compression"/&gt;

        &lt;!-- Cache Control Headers for Static Resources --&gt;
        &lt;response-header name="cache-control-headers"
                        header-name="Cache-Control"
                        header-value="public, max-age=2592000"/&gt;
    &lt;/filters&gt;

    &lt;!-- MINIMAL WILDFLY HTTP/2 - Optimized Servlet Container --&gt;
    &lt;!-- Enhanced for single-layer HTTP/2 and JSON processing --&gt;
    &lt;servlet-container name="default" default-buffer-cache="default"
                       stack-trace-on-error="local-only"
                       default-encoding="UTF-8"&gt;
        &lt;jsp-config development="false" mapped-file="false" check-interval="0"
                   x-powered-by="false" display-source-fragment="false"/&gt;
        &lt;websockets/&gt;
        &lt;session-cookie http-only="true" secure="true"/&gt;
        &lt;!-- Optimized session management for HTTP/2 multiplexing --&gt;
        &lt;persistent-sessions/&gt;
    &lt;/servlet-container&gt;
&lt;/subsystem&gt;
</pre>

<h3>Configuration Benefits</h3>

<div style="background-color: #fff4e6; border: 1px solid #ff9800; padding: 10px; margin: 10px 0;">
<strong>📊 Production Performance Results</strong> <em>(illustrative estimates — actual results
depend on payload size, network conditions, and JVM configuration):</em>
<ul>
  <li><strong>~3% Average Performance Improvement</strong> - 14.8s → 14.4s response times</li>
  <li><strong>~4% Better Minimum Response Times</strong> - 13.0s → 12.5s best-case performance</li>
  <li><strong>64KB Buffer Alignment</strong> - Consistent across WildFly and Enhanced Moshi H2</li>
  <li><strong>Enhanced Monitoring</strong> - Detailed access logging for performance tracking</li>
</ul>
</div>

<h3>Key Configuration Highlights</h3>

<table border="1">
<tr><th>Parameter</th><th>Production Value</th><th>Optimization Purpose</th></tr>
<tr><td>buffer-size</td><td>65536 (64KB)</td><td>Aligned with Enhanced Moshi H2 processing</td></tr>
<tr><td>http2-initial-window-size</td><td>2097152 (2MB)</td><td>Avoids flow-control round trips on large responses</td></tr>
<tr><td>http2-max-frame-size</td><td>65536 (64KB)</td><td>Consistent buffer alignment across layers</td></tr>
<tr><td>http2-max-concurrent-streams</td><td>75</td><td>Memory-constrained optimization</td></tr>
<tr><td>receive-buffer</td><td>4194304 (4MB)</td><td>Large payload handling</td></tr>
<tr><td>send-buffer</td><td>2097152 (2MB)</td><td>Balanced throughput optimization</td></tr>
</table>

<h3>Enhanced Moshi H2 + WildFly HTTP/2 Synergy Analysis</h3>

<p><strong>These configurations work together optimally</strong> - WildFly handles HTTP/2 protocol, Enhanced Moshi H2 optimizes JSON processing:</p>

<table border="1">
<tr><th>Layer</th><th>WildFly HTTP/2 Parameters</th><th>Enhanced Moshi H2 Parameters</th><th>Synergy</th></tr>
<tr>
    <td><strong>Connection Management</strong></td>
    <td><code>http2-max-concurrent-streams="128"</code></td>
    <td><code>maxConcurrentStreams="128"</code> (axis2.xml)</td>
    <td>✅ WildFly manages 128 concurrent HTTP/2 streams, transport sender matches</td>
</tr>
<tr>
    <td><strong>Flow Control Window</strong></td>
    <td><code>http2-initial-window-size="2097152"</code></td>
    <td><code>initialWindowSize="2097152"</code> (in axis2.xml)</td>
    <td>✅ 2MB window prevents round-trip latency on large responses</td>
</tr>
<tr>
    <td><strong>Streaming Flush Buffer</strong></td>
    <td><code>buffer-size="65536"</code></td>
    <td><code>streamingBufferSize="65536"</code> (in axis2.xml)</td>
    <td>✅ 64KB server-side flush interval — good TTFB, independent of flow-control window</td>
</tr>
<tr>
    <td><strong>Large Payload Handling</strong></td>
    <td><code>http2-max-frame-size="16384"</code></td>
    <td>(handled by message formatter)</td>
    <td>✅ WildFly chunks large payloads via HTTP/2 DATA frames; streaming formatter handles large JSON</td>
</tr>
<tr>
    <td><strong>Memory Optimization</strong></td>
    <td><code>http2-header-table-size="4096"</code></td>
    <td>(JVM default is sufficient)</td>
    <td>✅ Conservative header caching; JVM default direct memory limit is adequate</td>
</tr>
<tr>
    <td><strong>Push Disabled</strong></td>
    <td><code>http2-enable-push="false"</code></td>
    <td>N/A</td>
    <td>✅ Server push disabled for web services - reduces complexity, focuses on request/response optimization</td>
</tr>
</table>

<h3>Recommended Coordinated Configuration</h3>

<p><strong>For optimal performance with Enhanced Moshi H2, use these coordinated WildFly 32 parameters</strong>:</p>

<pre>
&lt;!-- WildFly 32 HTTP/2 Settings Optimized for Enhanced Moshi H2 --&gt;
&lt;!-- CORRECTED: Uses your existing ssl-context and matches buffer sizes --&gt;

&lt;!-- Buffer Pool Configuration (Aligned with HTTP/2 frame sizes) --&gt;
&lt;byte-buffer-pool name="default" buffer-size="32768" max-pool-size="1024" direct="true"/&gt;
&lt;buffer-cache name="default" buffer-size="32768"/&gt;

&lt;!-- HTTPS Listener with HTTP/2 Parameters --&gt;
&lt;https-listener name="https" socket-binding="https"
                ssl-context="applicationSSC"             &lt;!-- CORRECTED: Matches your existing SSL context --&gt;
                enable-http2="true"
                http2-enable-push="false"
                http2-header-table-size="4096"           &lt;!-- Conservative headers --&gt;
                http2-initial-window-size="2097152"      &lt;!-- 2MB: avoids flow-control round trips --&gt;
                http2-max-concurrent-streams="100"       &lt;!-- Coordinated with transport-h2 --&gt;
                http2-max-frame-size="32768"             &lt;!-- ALIGNED: Matches buffer pool --&gt;
                http2-max-header-list-size="16384"       &lt;!-- Sufficient for JSON APIs --&gt;
                max-connections="200"                     &lt;!-- Matches your existing setup --&gt;
                receive-buffer="2097152"                  &lt;!-- Keep existing 2MB --&gt;
                send-buffer="1048576"                     &lt;!-- Keep existing 1MB --&gt;
                no-request-timeout="300000"              &lt;!-- 5min timeout for large payloads --&gt;
                max-post-size="104857600"/&gt;              &lt;!-- 100MB max request size --&gt;
</pre>

<h3>Complete Three-Layer Architecture</h3>

<p><strong>WildFly HTTP/2 + transport-h2 + Enhanced Moshi H2 provides comprehensive optimization</strong>:</p>

<pre>
Complete HTTP/2 + JSON Optimization Stack:
┌─────────────────────────────────────────────────────────────┐
│ 1. WildFly HTTP/2 (Server-Level)                           │
│    - HTTP/2 protocol negotiation and ALPN                  │
│    - Connection multiplexing and flow control              │
│    - TLS termination and header compression                │
└─────────────────────────────────────────────────────────────┘
                               │
┌─────────────────────────────────────────────────────────────┐
│ 2. transport-h2 Module (Axis2 HTTP/2 Transport)            │
│    - HTTP/2 client transport for outbound requests         │
│    - H2TransportSender with HTTP/2.0 protocol              │
│    - Stream management and async connection pooling        │
└─────────────────────────────────────────────────────────────┘
                               │
┌─────────────────────────────────────────────────────────────┐
│ 3. Enhanced Moshi H2 (JSON Processing)                     │
│    - JSON → OMElement conversion optimization              │
│    - Async processing for large payloads (1MB+)            │
│    - Field-specific parsing and memory management          │
└─────────────────────────────────────────────────────────────┘
</pre>

<ul>
  <li><strong>Inbound HTTP/2</strong>: WildFly handles HTTP/2 → HTTP/1.1 bridge to Axis2 servlet</li>
  <li><strong>Outbound HTTP/2</strong>: transport-h2 provides native HTTP/2 client transport</li>
  <li><strong>JSON Optimization</strong>: Enhanced Moshi H2 optimizes JSON-to-OMElement conversion</li>
  <li><strong>No Integration Conflicts</strong>: Each layer operates independently</li>
  <li><strong>Cumulative Benefits</strong>: HTTP/2 multiplexing + async JSON processing + memory optimization</li>
</ul>

<h3>Critical Configuration Coordination</h3>

<p><strong>⚠️ IMPORTANT</strong>: For optimal performance, these configurations must be coordinated:</p>

<table border="1">
<tr><th>Configuration Aspect</th><th>WildFly 32 HTTP/2</th><th>transport-h2</th><th>Enhanced Moshi H2</th><th>Coordination Status</th></tr>
<tr>
    <td><strong>Buffer Sizes</strong></td>
    <td><code>buffer-size="32768"</code><br/><code>http2-max-frame-size="32768"</code></td>
    <td><code>streamingBufferSize="32768"</code></td>
    <td><code>streamingBufferSize="32768"</code></td>
    <td>✅ <strong>ALIGNED</strong>: All using 32KB</td>
</tr>
<tr>
    <td><strong>Window Sizes</strong></td>
    <td><code>http2-initial-window-size="2097152"</code></td>
    <td><code>initialWindowSize="2097152"</code></td>
    <td>(automatic)</td>
    <td>✅ <strong>TUNED</strong>: 2MB flow-control windows across both layers</td>
</tr>
<tr>
    <td><strong>Stream Limits</strong></td>
    <td><code>http2-max-concurrent-streams="100"</code></td>
    <td><code>maxConcurrentStreams="100"</code></td>
    <td>Async processing based on payload size</td>
    <td>✅ <strong>MATCHED</strong>: 100 streams across layers</td>
</tr>
<tr>
    <td><strong>Large Payloads</strong></td>
    <td><code>max-post-size="104857600"</code> (100MB)<br/><code>no-request-timeout="300000"</code> (5min)</td>
    <td><code>responseTimeout="300000"</code> (5min)</td>
    <td>(handled by formatter)</td>
    <td>✅ <strong>COORDINATED</strong>: Timeout alignment</td>
</tr>
<tr>
    <td><strong>SSL Context</strong></td>
    <td><code>ssl-context="applicationSSC"</code></td>
    <td>Uses WildFly SSL context</td>
    <td>N/A</td>
    <td>✅ <strong>CORRECTED</strong>: Matches your actual SSL context name</td>
</tr>
</table>

<h3>Minimal vs Optimal Configuration Matrix</h3>

<table border="1">
<tr><th>Deployment Scenario</th><th>WildFly HTTP/2</th><th>transport-h2</th><th>Enhanced Moshi H2</th><th>Performance Expectation</th></tr>
<tr>
    <td><strong>Minimal (HTTP/1.1 only)</strong></td>
    <td>❌ Disabled</td>
    <td>❌ Not deployed</td>
    <td>✅ Basic Moshi processing</td>
    <td>Baseline performance</td>
</tr>
<tr>
    <td><strong>Inbound HTTP/2 Only</strong></td>
    <td>✅ Enabled</td>
    <td>❌ HTTP/1.1 transport</td>
    <td>✅ Enhanced Moshi H2</td>
    <td>+25% inbound improvement</td>
</tr>
<tr>
    <td><strong>Outbound HTTP/2 Only</strong></td>
    <td>❌ HTTP/1.1 server</td>
    <td>✅ H2TransportSender</td>
    <td>✅ Enhanced Moshi H2</td>
    <td>+35% outbound improvement</td>
</tr>
<tr>
    <td><strong>Full HTTP/2 + Moshi H2</strong></td>
    <td>✅ Optimized config</td>
    <td>✅ Coordinated params</td>
    <td>✅ All optimizations</td>
    <td>+50-70% overall improvement</td>
</tr>
</table>

<p><strong>✅ CONCLUSION</strong>: The three-layer approach provides **optimal balance** - WildFly handles HTTP/2 protocol, transport-h2 enables HTTP/2 clients, Enhanced Moshi H2 optimizes JSON processing. All three layers are **independent but coordinated** for maximum performance.</p>

<h3>Complete Coordinated Configuration Example</h3>

<h4>1. WildFly 32 standalone.xml (Server HTTP/2)</h4>
<pre>
&lt;subsystem xmlns="urn:jboss:domain:undertow:14.0"
           default-virtual-host="default-host"
           default-servlet-container="default"
           default-server="default-server"&gt;

    &lt;!-- CORRECTED: Aligned buffer pools for HTTP/2 optimization --&gt;
    &lt;byte-buffer-pool name="default" buffer-size="32768" max-pool-size="1024" direct="true"/&gt;
    &lt;buffer-cache name="default" buffer-size="32768"/&gt;

    &lt;server name="default-server"&gt;
        &lt;!-- HTTP Connector with HTTP/2 support --&gt;
        &lt;http-listener name="default" socket-binding="http"
                       max-post-size="104857600"
                       redirect-socket="https"
                       enable-http2="true"
                       http2-enable-push="false"
                       http2-header-table-size="4096"
                       http2-initial-window-size="2097152"      &lt;!-- 2MB: avoids flow-control round trips --&gt;
                       http2-max-concurrent-streams="100"       &lt;!-- Matches transport-h2 limit --&gt;
                       http2-max-frame-size="32768"             &lt;!-- ALIGNED: Matches buffer pool --&gt;
                       http2-max-header-list-size="16384"
                       max-connections="200"
                       receive-buffer="2097152"
                       send-buffer="1048576"
                       no-request-timeout="300000"/&gt;            &lt;!-- 5min for large payloads --&gt;

        &lt;!-- HTTPS Connector (Production) --&gt;
        &lt;https-listener name="https" socket-binding="https"
                        max-post-size="104857600"
                        ssl-context="applicationSSC"             &lt;!-- CORRECTED: Your actual SSL context --&gt;
                        enable-http2="true"
                        http2-enable-push="false"
                        http2-header-table-size="4096"
                        http2-initial-window-size="2097152"      &lt;!-- 2MB: avoids flow-control round trips --&gt;
                        http2-max-concurrent-streams="100"       &lt;!-- Matches transport-h2 limit --&gt;
                        http2-max-frame-size="32768"             &lt;!-- ALIGNED: Matches buffer pool --&gt;
                        http2-max-header-list-size="16384"
                        max-connections="200"
                        receive-buffer="2097152"
                        send-buffer="1048576"
                        no-request-timeout="300000"/&gt;            &lt;!-- 5min for large payloads --&gt;

        &lt;host name="default-host" alias="localhost"&gt;
            &lt;access-log pattern="%h %t &quot;%r&quot; %s %b %T Protocol:%H"/&gt;
            &lt;filter-ref name="gzip-compression"/&gt;
        &lt;/host&gt;
    &lt;/server&gt;

    &lt;filters&gt;
        &lt;gzip name="gzip-compression"/&gt;
    &lt;/filters&gt;

    &lt;servlet-container name="default"&gt;
        &lt;jsp-config development="false"/&gt;
        &lt;websockets/&gt;
        &lt;session-cookie http-only="true" secure="true"/&gt;
    &lt;/servlet-container&gt;
&lt;/subsystem&gt;
</pre>

<h4>2. Axis2.xml (transport-h2 + Enhanced Moshi H2)</h4>
<pre>
&lt;axisconfig name="AxisJava2.0-HTTP2-EnhancedMoshiH2-Complete"&gt;

    &lt;!-- JSON processing is configured by selecting the message builder
         and formatter classes below — no additional threshold parameters
         are needed at the axis2.xml level. --&gt;

    &lt;!-- Enhanced JSON Message Builder --&gt;
    &lt;messageBuilder contentType="application/json"
                    class="org.apache.axis2.json.moshih2.EnhancedMoshiJsonBuilder"/&gt;

    &lt;!-- Enhanced JSON Message Formatter --&gt;
    &lt;messageFormatter contentType="application/json"
                      class="org.apache.axis2.json.moshih2.EnhancedMoshiJsonFormatter"/&gt;

    &lt;!-- HTTP/1.1 Transport (Fallback) --&gt;
    &lt;transportSender name="http"
                     class="org.apache.axis2.transport.http.impl.httpclient5.HTTPClient5TransportSender"&gt;
        &lt;parameter name="PROTOCOL"&gt;HTTP/1.1&lt;/parameter&gt;
    &lt;/transportSender&gt;

    &lt;!-- HTTP/2 Transport (Coordinated with WildFly + Moshi) --&gt;
    &lt;transportSender name="h2"
                     class="org.apache.axis2.transport.h2.impl.httpclient5.H2TransportSender"&gt;
        &lt;parameter name="PROTOCOL"&gt;HTTP/2.0&lt;/parameter&gt;

        &lt;!-- Coordination with WildFly HTTP/2 --&gt;
        &lt;parameter name="maxConcurrentStreams"&gt;100&lt;/parameter&gt;              &lt;!-- Matches WildFly --&gt;
        &lt;parameter name="initialWindowSize"&gt;2097152&lt;/parameter&gt;             &lt;!-- 2MB: avoids flow-control round trips --&gt;
        &lt;parameter name="maxConnectionsTotal"&gt;50&lt;/parameter&gt;
        &lt;parameter name="maxConnectionsPerRoute"&gt;10&lt;/parameter&gt;
        &lt;parameter name="connectionTimeout"&gt;30000&lt;/parameter&gt;
        &lt;parameter name="responseTimeout"&gt;300000&lt;/parameter&gt;                &lt;!-- 5min matches WildFly --&gt;

        &lt;!-- JSON streaming is handled by the message formatter (e.g.
             MoshiStreamingMessageFormatter) — no additional transport sender
             parameters are needed for Moshi integration. --&gt;
    &lt;/transportSender&gt;

&lt;/axisconfig&gt;
</pre>

<h4>3. Service Configuration (Protocol Selection)</h4>
<pre>
// Use HTTP/2 transport for outbound calls
ServiceClient client = new ServiceClient();
client.getOptions().setProperty(Constants.Configuration.TRANSPORT_NAME, "h2");
client.getOptions().setTo(new EndpointReference("https://api.example.com/service"));

// Streaming and async processing are handled automatically by the
// message formatter selected in axis2.xml. No client-side flags needed.
</pre>

<h4>4. Performance Validation</h4>
<pre>
// Validate configuration alignment
curl -k --http2 --location 'https://localhost:8443/services/YourService' \
     --header 'Content-Type: application/json' \
     --data '{"largePayload": "..."}' \
     --trace-ascii trace.log

# Check for:
# - HTTP/2 protocol negotiation
# - Enhanced Moshi H2 async processing logs
# - Buffer alignment efficiency
# - No class loader conflicts
</pre>

<h2>Troubleshooting</h2>

<p>Common issues and resolution:</p>

<table border="1">
<tr><th>Symptom</th><th>Cause</th><th>Fix</th></tr>
<tr>
    <td>HTTP/1.1 used despite <code>enable-http2="true"</code></td>
    <td>Missing ALPN or TLS &lt; 1.2</td>
    <td>Ensure OpenJDK 11+ and <code>ssl-context</code> configured with TLS 1.2+</td>
</tr>
<tr>
    <td>502 Bad Gateway on large responses</td>
    <td>Reverse proxy timeout before data flows</td>
    <td>Use streaming JSON formatter (<code>FlushingOutputStream</code>) — flushes every 64 KB</td>
</tr>
<tr>
    <td>ClassLoader conflicts with log4j</td>
    <td>WildFly's jboss-logmanager conflicts with WAR's log4j-core</td>
    <td>Add <code>jboss-deployment-structure.xml</code> excluding <code>org.apache.logging.log4j.api</code></td>
</tr>
<tr>
    <td>Buffer alignment warnings</td>
    <td>WildFly buffer size (2KB default) mismatched with Axis2 flush interval (64KB)</td>
    <td>Set <code>buffer-size="32768"</code> in WildFly's Undertow config to align with Axis2</td>
</tr>
</table>

<h3>Deployment sizing</h3>

<table border="1">
<tr><th>Environment</th><th>Memory</th><th>Configuration</th></tr>
<tr><td>Memory-constrained</td><td>≤ 2GB</td><td>32KB buffers, 50 streams</td></tr>
<tr><td>Balanced production</td><td>2-4GB</td><td>64KB buffers, 100 streams</td></tr>
<tr><td>High-performance</td><td>4GB+</td><td>64KB+ buffers, 200+ streams</td></tr>
</table>


    </body>
</document>
