SONAR-14870 update docs

server/sonar-docs/src/pages/setup/install-server.md

@@ -288,12 +288,12 @@ For some proxies, the exception "java.net.ProtocolException: Server redirected t
 
 SonarQube starts an Elasticsearch process, and the same account that is running SonarQube itself will be used for the Elasticsearch process. Since Elasticsearch cannot be run as `root`, that means SonarQube can't be either. You must choose some other, non-`root` account with which to run SonarQube, preferably an account dedicated to the purpose.
 
-### Sonarqube fails to decorate merge requests when DNS entry to ALM changes
+### Sonarqube DNS cache
 
-If you run SonarQube in an environment with a lot of DNS friction, you should define a DNS cache time to live policy as, by default, SonarQube will hold the DNS cache until it is restarted. You can set this policy to five seconds by doing the following: 
+When reporting Quality Gate status to DevOps platforms, SonarQube uses a DNS cache time to live policy of 30 seconds. If necessary, you can change this setting in your JVM:
 
 ```bash
 echo "networkaddress.cache.ttl=5" >> "${JAVA_HOME}/conf/security/java.security" 
 ```
 
-Please be aware that this increases the risk of DNS spoofing attacks.
+Please be aware that low values increases the risk of DNS spoofing attacks.