title: Unable to acquire JDBC Connection in SpringBoot app
body: <p>I have a Microservices‑Based Application, each Microservice is a SpringBoot 2.0.3.RELEASE app., but after my 4rth Microservices launched I have this error:</p>
  
  <pre><code>    Unable to acquire JDBC Connection; nested exception is org.hibernate.exception.JDBCConnectionException: Unable to acquire JDBC Connection
  ..
  Caused by: com.mysql.jdbc.exceptions.jdbc4.MySQLNonTransientConnectionException: Too many connections
  </code></pre>
  
  <p>I would like to know how to reduce the <code>maximumPoolSize</code> or if there is a way to know <code>maximumPoolSize</code> because I have't seen anything related when the app starts</p>