db.DbTransaction getConnection: null
java.sql.SQLException: Transient error, please try again.
at
com.google.appengine.api.rdbms.RdbmsApiProxyClient$ApiProxyBlockingInterface.makeSyncCall(RdbmsApiProxyClient.java:108)
at com.google.appengine.api.rdbms.RdbmsApiProxyClient$ApiProxyBlockingInterface.openConnection(RdbmsApiProxyClient.java:71)
at com.google.cloud.sql.jdbc.internal.SqlProtoClient.openConnection(SqlProtoClient.java:58)
at com.google.cloud.sql.jdbc.Driver.connect(Driver.java:66)
at com.google.cloud.sql.jdbc.Driver.connect(Driver.java:26)
at java.sql.DriverManager.getConnection(DriverManager.java:620)
at java.sql.DriverManager.getConnection(DriverManager.java:222)
at db.DbTransaction.getConnection(DbTransaction.java:44)
When i restarted the instance of Google Cloud SQL, it is resolved. What the reason behind it and how can i solve it. I have used servlet based connection pooling in this application. Whether the cause of exception have an relation to connection pooling or have any issue related to An App Engine instance cannot have more than 30 concurrent connections to Google Cloud SQL, so a leak will eventually cause new connections to fail (https://developers.google.com/appengine/docs/java/cloud-sql/).
