Unexpected GDS Exception: 335544726. Error reading data from the connection

Question

I have a Web app running on Apache Tomcat 6, using ZK, Hibernate and Jaybird JDBC for accessing a Firebird database. For some unknown reason, after a not yet mapped operation in the app that performs a dynamic SQL, it crashes with the following exception:

ERROR: org.springframework.transaction.TransactionSystemException: Could not roll back JPA transaction; nested exception is javax.persistence.PersistenceException: unexpected error when rollbacking javax.persistence.PersistenceException: unexpected error when rollbacking org.hibernate.TransactionException: JDBC rollback failed [SQL: 335544726, HY000] org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544726. Error reading data from the connection.

Reason: Error reading data from the connection. ...

Then, any operation performed by the user after it causes the following error:

ERROR: javax.persistence.PersistenceException: org.hibernate.exception.GenericJDBCException: could not execute query org.hibernate.exception.GenericJDBCException: could not execute query [SQL: 335544721, HY000] org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544721. Unable to complete network request to host "". Reason: Unable to complete network request to host "".

And the system crashes down, like if it had lost the connection with the database.

Has anyone experienced it before?

Answer 1

After some research and tests, I've got to understand what was happening.

The problem was happening when a user was performing a specific search in the app using a string with size greater than the target table field's size. So, when the system executed the HQL query with the string input as a parameter, the system crashed down - like when comparing a string with length 20 to a varchar(18) field.

The solution was simple: limit the size of the input string in the search field.

Hope this helps anyone in the future.

Answer 2

You're not being able to connect to the database. The code 335544721 is a result of an active denial of access, that may be caused by a variety of elements, such as bad login, firewall rules avoiding the connection or antivirus blockage

Answer 3

I also had a similar problem, in my case it happened because I used LIKE condition and together with two "%" signs the length of parameter exceeded the length of the field.

So, for example, if I have a table:

create table TEST (name varchar(5) default '' not null);

When I try to search by the following condition and have parameter param1 = '%name1%' (as you see 'name1' is valid for varchar(5) field):

select * from TEST where name like :param1;

I have the same error in hibernate, and after this error I cannot execute any queries, probably because hibernate session is broken.

Hope it may help somebody.

Answer 4

I solved it by restarting the FirebirdGuardianService on the server.