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itemtype="https://schema.org/ListItem" class="breadcrumbs__item breadcrumbs__item--active"><span class="breadcrumbs__link" itemprop="name">Proxy support with SNI routing</span><meta itemprop="position" content="2"></li></ul></nav><span class="theme-doc-version-badge badge badge--secondary">Version: 3.2.x</span><div class="tocCollapsible_ETCw theme-doc-toc-mobile tocMobile_ITEo"><button type="button" class="clean-btn tocCollapsibleButton_TO0P">On this page</button></div><div class="theme-doc-markdown markdown"><header><h1>Proxy support with SNI routing</h1></header><p>A proxy server is an intermediary server that forwards requests from multiple clients to different servers across the Internet. The proxy server acts as a &quot;traffic cop&quot; in both forward and reverse proxy scenarios, and benefits your system such as load balancing, performance, security, auto-scaling, and so on.</p><p>The proxy in Pulsar acts as a reverse proxy, and creates a gateway in front of brokers. Proxies such as Apache Traffic Server (ATS), HAProxy, Nginx, and Envoy are not supported in Pulsar. These proxy-servers support <strong>SNI routing</strong>. SNI routing is used to route traffic to a destination without terminating the SSL connection. Layer 4 routing provides greater transparency because the outbound connection is determined by examining the destination address in the client TCP packets.</p><p>Pulsar clients (Java, C++, Python) support <a href="https://github.com/apache/pulsar/wiki/PIP-60:-Support-Proxy-server-with-SNI-routing" target="_blank" rel="noopener noreferrer">SNI routing protocol</a>, so you can connect to brokers through the proxy. This document walks you through how to set up the ATS proxy, enable SNI routing, and connect Pulsar client to the broker through the ATS proxy.</p><h2 class="anchor anchorWithStickyNavbar_LWe7" id="ats-sni-routing-in-pulsar">ATS-SNI Routing in Pulsar<a href="#ats-sni-routing-in-pulsar" class="hash-link" aria-label="Direct link to ATS-SNI Routing in Pulsar" title="Direct link to ATS-SNI Routing in Pulsar"></a></h2><p>To support <a href="https://docs.trafficserver.apache.org/en/latest/admin-guide/layer-4-routing.en.html" target="_blank" rel="noopener noreferrer">layer-4 SNI routing</a> with ATS, the inbound connection must be a TLS connection. Pulsar client supports SNI routing protocol on TLS connection, so when Pulsar clients connect to broker through ATS proxy, Pulsar uses ATS as a reverse proxy.</p><p>Pulsar supports SNI routing for geo-replication, so brokers can connect to brokers in other clusters through the ATS proxy.</p><p>This section explains how to set up and use ATS as a reverse proxy, so Pulsar clients can connect to brokers through the ATS proxy using the SNI routing protocol on TLS connection.</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="set-up-ats-proxy-for-layer-4-sni-routing">Set up ATS Proxy for layer-4 SNI routing<a href="#set-up-ats-proxy-for-layer-4-sni-routing" class="hash-link" aria-label="Direct link to Set up ATS Proxy for layer-4 SNI routing" title="Direct link to Set up ATS Proxy for layer-4 SNI routing"></a></h3><p>To set up ATS proxy for layer 4 SNI routing, you need to configure the <code>records.conf</code> and <code>ssl_server_name.conf</code> files.</p><p><img loading="lazy" alt="Pulsar client SNI" src="/assets/images/pulsar-sni-client-8daa2555e32173988e0eb6753e202e96.png" width="1518" height="974" class="img_ev3q"></p><p>The <a href="https://docs.trafficserver.apache.org/en/latest/admin-guide/files/records.config.en.html" target="_blank" rel="noopener noreferrer">records.config</a> file is located in the <code>/usr/local/etc/trafficserver/</code> directory by default. The file lists configurable variables used by the ATS.</p><p>To configure the <code>records.config</code> files, complete the following steps.</p><ol><li>Update TLS port (<code>http.server_ports</code>) on which proxy listens, and update proxy certs (<code>ssl.client.cert.path</code> and <code>ssl.client.cert.filename</code>) to secure TLS tunneling.</li><li>Configure server ports (<code>http.connect_ports</code>) used for tunneling to the broker. If Pulsar brokers are listening on <code>4443</code> and <code>6651</code> ports, add the brokers service port in the <code>http.connect_ports</code> configuration.</li></ol><p>The following is an example.</p><div class="language-conf codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-conf codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain"># PROXY TLS PORT</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">CONFIG proxy.config.http.server_ports STRING 4443:ssl 4080</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"># PROXY CERTS FILE PATH</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">CONFIG proxy.config.ssl.client.cert.path STRING /proxy-cert.pem</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"># PROXY KEY FILE PATH</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">CONFIG proxy.config.ssl.client.cert.filename STRING /proxy-key.pem</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"># The range of origin server ports that can be used for tunneling via CONNECT. # Traffic Server allows tunnels only to the specified ports. Supports both wildcards (*) and ranges (e.g. 0-1023).</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">CONFIG proxy.config.http.connect_ports STRING 4443 6651</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>The <code>ssl_server_name</code> file is used to configure TLS connection handling for inbound and outbound connections. The configuration is determined by the SNI values provided by the inbound connection. The file consists of a set of configuration items, and each is identified by an SNI value (<code>fqdn</code>). When an inbound TLS connection is made, the SNI value from the TLS negotiation is matched with the items specified in this file. If the values match, the values specified in that item override the default values.</p><p>The following example shows the mapping of the inbound SNI hostname coming from the client, and the actual broker service URL where requests should be redirected. For example, if the client sends the SNI header <code>pulsar-broker1</code>, the proxy creates a TLS tunnel by redirecting the request to the <code>pulsar-broker1:6651</code> service URL.</p><div class="language-conf codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-conf codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">server_config = {</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  {</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     fqdn = &#x27;pulsar-broker-vip&#x27;,</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     # Forward to Pulsar broker which is listening on 6651</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     tunnel_route = &#x27;pulsar-broker-vip:6651&#x27;</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  },</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  {</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     fqdn = &#x27;pulsar-broker1&#x27;,</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     # Forward to Pulsar broker-1 which is listening on 6651</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     tunnel_route = &#x27;pulsar-broker1:6651&#x27;</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  },</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  {</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     fqdn = &#x27;pulsar-broker2&#x27;,</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     # Forward to Pulsar broker-2 which is listening on 6651</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">     tunnel_route = &#x27;pulsar-broker2:6651&#x27;</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">  },</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">}</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>After you configure the <code>ssl_server_name.config</code> and <code>records.config</code> files, the ATS-proxy server handles SNI routing and creates TCP tunnel between the client and the broker.</p><h3 class="anchor anchorWithStickyNavbar_LWe7" id="configure-pulsar-client-with-sni-routing">Configure Pulsar-client with SNI routing<a href="#configure-pulsar-client-with-sni-routing" class="hash-link" aria-label="Direct link to Configure Pulsar-client with SNI routing" title="Direct link to Configure Pulsar-client with SNI routing"></a></h3><p>ATS SNI-routing works only with TLS. You need to enable TLS for the ATS proxy and brokers first, configure the SNI routing protocol, and then connect Pulsar clients to brokers through ATS proxy. Pulsar clients support SNI routing by connecting to the proxy, and sending the target broker URL to the SNI header. This process is processed internally. You only need to configure the following proxy configuration initially when you create a Pulsar client to use the SNI routing protocol.</p><div class="tabs-container tabList__CuJ"><ul role="tablist" aria-orientation="horizontal" class="tabs"><li role="tab" tabindex="0" aria-selected="true" class="tabs__item tabItem_LNqP tabs__item--active">Java</li><li role="tab" tabindex="-1" aria-selected="false" class="tabs__item tabItem_LNqP">C++</li><li role="tab" tabindex="-1" aria-selected="false" class="tabs__item tabItem_LNqP">Python</li></ul><div class="margin-top--md"><div role="tabpanel" class="tabItem_Ymn6"><div class="language-java codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-java codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token class-name">String</span><span class="token plain"> brokerServiceUrl </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;pulsar+ssl://pulsar-broker-vip:6651/&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token class-name">String</span><span class="token plain"> proxyUrl </span><span class="token operator">=</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;pulsar+ssl://ats-proxy:443&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token class-name">ClientBuilder</span><span class="token plain"> clientBuilder </span><span class="token operator">=</span><span class="token plain"> </span><span class="token class-name">PulsarClient</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">builder</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">serviceUrl</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">brokerServiceUrl</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">tlsTrustCertsFilePath</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token constant" style="color:rgb(189, 147, 249)">TLS_TRUST_CERT_FILE_PATH</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">enableTls</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token boolean">true</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">allowTlsInsecureConnection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">proxyServiceUrl</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">proxyUrl</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token class-name">ProxyProtocol</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token constant" style="color:rgb(189, 147, 249)">SNI</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">        </span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">operationTimeout</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token number">1000</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token class-name">TimeUnit</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token constant" style="color:rgb(189, 147, 249)">MILLISECONDS</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token class-name">Map</span><span class="token generics punctuation" style="color:rgb(248, 248, 242)">&lt;</span><span class="token generics class-name">String</span><span class="token generics punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token generics"> </span><span class="token generics class-name">String</span><span class="token generics punctuation" style="color:rgb(248, 248, 242)">&gt;</span><span class="token plain"> authParams </span><span class="token operator">=</span><span class="token plain"> </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">new</span><span class="token plain"> </span><span class="token class-name">HashMap</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">authParams</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">put</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;tlsCertFile&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(189, 147, 249)">TLS_CLIENT_CERT_FILE_PATH</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">authParams</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">put</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;tlsKeyFile&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token constant" style="color:rgb(189, 147, 249)">TLS_CLIENT_KEY_FILE_PATH</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">clientBuilder</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">authentication</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token class-name">AuthenticationTls</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">class</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">getName</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> authParams</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain"></span><span class="token class-name">PulsarClient</span><span class="token plain"> pulsarClient </span><span class="token operator">=</span><span class="token plain"> clientBuilder</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">build</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div></div><div role="tabpanel" class="tabItem_Ymn6" hidden=""><div class="language-cpp codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-cpp codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">ClientConfiguration config </span><span class="token operator">=</span><span class="token plain"> </span><span class="token function" style="color:rgb(80, 250, 123)">ClientConfiguration</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">config</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">setUseTls</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token boolean">true</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">config</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">setTlsTrustCertsFilePath</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/cacert.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">config</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">setTlsAllowInsecureConnection</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token boolean">false</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">config</span><span class="token punctuation" style="color:rgb(248, 248, 242)">.</span><span class="token function" style="color:rgb(80, 250, 123)">setAuth</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain">pulsar</span><span class="token double-colon punctuation" style="color:rgb(248, 248, 242)">::</span><span class="token class-name">AuthTls</span><span class="token double-colon punctuation" style="color:rgb(248, 248, 242)">::</span><span class="token function" style="color:rgb(80, 250, 123)">create</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">            </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/client-cert.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/client-key.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">Client </span><span class="token function" style="color:rgb(80, 250, 123)">client</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;pulsar+ssl://ats-proxy:443&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> config</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token punctuation" style="color:rgb(248, 248, 242)">;</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div></div><div role="tabpanel" class="tabItem_Ymn6" hidden=""><div class="language-python codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-python codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">from</span><span class="token plain"> pulsar </span><span class="token keyword" style="color:rgb(189, 147, 249);font-style:italic">import</span><span class="token plain"> Client</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> AuthenticationTLS</span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain" style="display:inline-block"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">auth </span><span class="token operator">=</span><span class="token plain"> AuthenticationTLS</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/my-role.cert.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"> </span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/my-role.key-pk8.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">client </span><span class="token operator">=</span><span class="token plain"> Client</span><span class="token punctuation" style="color:rgb(248, 248, 242)">(</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;pulsar+ssl://ats-proxy:443&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">                tls_trust_certs_file_path</span><span class="token operator">=</span><span class="token string" style="color:rgb(255, 121, 198)">&quot;/path/to/ca.cert.pem&quot;</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">                tls_allow_insecure_connection</span><span class="token operator">=</span><span class="token boolean">False</span><span class="token punctuation" style="color:rgb(248, 248, 242)">,</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">                authentication</span><span class="token operator">=</span><span class="token plain">auth</span><span class="token punctuation" style="color:rgb(248, 248, 242)">)</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div></div></div></div><h3 class="anchor anchorWithStickyNavbar_LWe7" id="pulsar-geo-replication-with-sni-routing">Pulsar geo-replication with SNI routing<a href="#pulsar-geo-replication-with-sni-routing" class="hash-link" aria-label="Direct link to Pulsar geo-replication with SNI routing" title="Direct link to Pulsar geo-replication with SNI routing"></a></h3><p>You can use the ATS proxy for geo-replication. Pulsar brokers can connect to brokers in geo-replication by using SNI routing. To enable SNI routing for broker connection cross clusters, you need to configure SNI proxy URL to the cluster metadata. If you have configured SNI proxy URL in the cluster metadata, you can connect to broker cross clusters through the proxy over SNI routing.</p><p><img loading="lazy" alt="Pulsar geo-replication with SNI routing" src="/assets/images/pulsar-sni-geo-296a6da9d1e67d9110e6f04a3132889b.png" width="1494" height="598" class="img_ev3q"></p><p>In this example, a Pulsar cluster is deployed into two separate regions, <code>us-west</code> and <code>us-east</code>. Both regions are configured with ATS proxy, and brokers in each region run behind the ATS proxy. We configure the cluster metadata for both clusters, so brokers in one cluster can use SNI routing and connect to brokers in other clusters through the ATS proxy.</p><p>(a) Configure the cluster metadata for <code>us-east</code> with <code>us-east</code> broker service URL and <code>us-east</code> ATS proxy URL with SNI proxy-protocol.</p><div class="language-shell codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-shell codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">./pulsar-admin clusters update </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --broker-url-secure pulsar+ssl://east-broker-vip:6651 </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --url http://east-broker-vip:8080 </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --proxy-protocol SNI </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --proxy-url pulsar+ssl://east-ats-proxy:443</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" aria-hidden="true"><svg class="copyButtonIcon_y97N" viewBox="0 0 24 24"><path d="M19,21H8V7H19M19,5H8A2,2 0 0,0 6,7V21A2,2 0 0,0 8,23H19A2,2 0 0,0 21,21V7A2,2 0 0,0 19,5M16,1H4A2,2 0 0,0 2,3V17H4V3H16V1Z"></path></svg><svg class="copyButtonSuccessIcon_LjdS" viewBox="0 0 24 24"><path d="M21,7L9,19L3.5,13.5L4.91,12.09L9,16.17L19.59,5.59L21,7Z"></path></svg></span></button></div></div></div><p>(b) Configure the cluster metadata for <code>us-west</code> with <code>us-west</code> broker service URL and <code>us-west</code> ATS proxy URL with SNI proxy-protocol.</p><div class="language-shell codeBlockContainer_Ckt0 theme-code-block" style="--prism-color:#F8F8F2;--prism-background-color:#282A36"><div class="codeBlockContent_biex"><pre tabindex="0" class="prism-code language-shell codeBlock_bY9V thin-scrollbar"><code class="codeBlockLines_e6Vv"><span class="token-line" style="color:#F8F8F2"><span class="token plain">./pulsar-admin clusters update </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --broker-url-secure pulsar+ssl://west-broker-vip:6651 </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --url http://west-broker-vip:8080 </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --proxy-protocol SNI </span><span class="token punctuation" style="color:rgb(248, 248, 242)">\</span><span class="token plain"></span><br></span><span class="token-line" style="color:#F8F8F2"><span class="token plain">    --proxy-url pulsar+ssl://west-ats-proxy:443</span><br></span></code></pre><div class="buttonGroup__atx"><button type="button" aria-label="Copy code to clipboard" title="Copy" class="clean-btn"><span class="copyButtonIcons_eSgA" 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