RestTemplate + ConnectionPoolTimeoutException: Timeout waiting for connection from pool

Question

I got this error all of a sudden in production while the application was not under any load.

The issue happened when my code tries to send the PUT message using spri

Answer 1

The problem is the HTTP client connections aren't being closed. I had the same problem with a service that only has about 1 request per second.

"exception":"org.apache.http.conn.ConnectionPoolTimeoutException: Timeout waiting for connection from pool"

You need to add a finally block and close the connection.