<h2 dir="auto">Question</h2>
<p dir="auto"><strong>For English only</strong>, other languages will not accept.</p>
<p dir="auto">Before asking a question, make sure you have:</p>
<ul dir="auto">
<li>Googled your question.</li>
<li>Searched open and closed <a href="https://github.com/apache/shardingsphere/issues">GitHub issues</a>.</li>
<li>Read documentation: <a href="https://shardingsphere.apache.org/document/current/en/overview" rel="nofollow">ShardingSphere Doc</a>.</li>
</ul>
<p dir="auto">Please pay attention on issues you submitted, because we maybe need more details.<br>
If no response anymore and we cannot reproduce it on current information, we will <strong>close it</strong>.</p>
<p dir="auto">Which version of ShardingSphere did you use?<br>
ghcr.io/apache/shardingsphere-proxy:c9cc117c8f4b42c220f89c92851bf945c40c71b0  （helm cluster）</p>
<p dir="auto">Which project did you use? ShardingSphere-JDBC or ShardingSphere-Proxy?<br>
ShardingSphere-Proxy</p>
<p dir="auto">Expected behavior<br>
JDBC connection is normal.</p>
<p dir="auto">Actual behavior<br>
java.sql.SQLException: Unknown system variable 'query_cache_size'<br>
<a target="_blank" rel="noopener noreferrer nofollow" href="https://user-images.githubusercontent.com/51192624/184082438-f5cfd40b-d56b-4861-bd8e-892bfabe8133.png"><img src="https://user-images.githubusercontent.com/51192624/184082438-f5cfd40b-d56b-4861-bd8e-892bfabe8133.png" alt="image" style="max-width: 100%;"></a></p>
<p dir="auto">Environment Configurations</p>
<div class="snippet-clipboard-content notranslate position-relative overflow-auto" data-snippet-clipboard-copy-content="props:
  check-duplicate-table-enabled: false
  check-table-metadata-enabled: true
  kernel-executor-size: 16
  max-connections-size-per-query: 1
  proxy-backend-driver-type: JDBC
  proxy-backend-executor-suitable: OLAP
  proxy-backend-query-fetch-size: -1
  proxy-frontend-executor-size: 0
  proxy-frontend-flush-threshold: 128
  proxy-frontend-max-connections: 0
  proxy-hint-enabled: true
  proxy-opentracing-enabled: false
  show-process-list-enabled: false
  sql-federation-enabled: false
  sql-show: true
  proxy-mysql-default-version: 8.0.21"><pre class="notranslate"><code class="notranslate">props:
  check-duplicate-table-enabled: false
  check-table-metadata-enabled: true
  kernel-executor-size: 16
  max-connections-size-per-query: 1
  proxy-backend-driver-type: JDBC
  proxy-backend-executor-suitable: OLAP
  proxy-backend-query-fetch-size: -1
  proxy-frontend-executor-size: 0
  proxy-frontend-flush-threshold: 128
  proxy-frontend-max-connections: 0
  proxy-hint-enabled: true
  proxy-opentracing-enabled: false
  show-process-list-enabled: false
  sql-federation-enabled: false
  sql-show: true
  proxy-mysql-default-version: 8.0.21
</code></pre></div>
<p dir="auto">My mysql cloud server version is <code class="notranslate">8.0.21-5</code></p>
<p dir="auto">I need a little help.</p>