How to resolve connection errors - KostasMparmparousis/uLookup GitHub Wiki

DS Connection Errors

Log:

Caused by: javax.naming.AuthenticationException: [LDAP: error code 49 - Invalid Credentials]

Probable cause: Wrong/Old credentials.
Solution: Look in the "identity" shared folder for a email by the institution in question.

Log:

Caused by: javax.naming.CommunicationException: ds.xxx.gr:636 [Root exception is java.net.ConnectException: Connection timed out (Connection timed out)]

Probable cause: DS Firewall blocking your request.
Solution: The problem will resolve itself, when you ask the institution to allow requests from the production VM address. However, if you are desperate to make it work from your localhost, you can do the following:

(connect via ssh to access)
ssh -p 65432 -NTf -L 1636:ds.xxx.gr:636 access.noc.uoa.gr
(add ds.xxx.gr to your /etc/hosts)
127.0.0.1	localhost ds.xxx.gr
(retry the connection attempt)

DB View Connection Errors

Log:

Caused by: com.microsoft.sqlserver.jdbc.SQLServerException: Login failed for user '...'. ClientConnectionId:eec5b81d-64f5-423c-91a7-a4bacecc7148

or

Caused by: java.sql.SQLException: Access denied for user 'username'@'connection_url' (using password: YES)

or 

(no log for oracle servers annoyingly, only an enormous request time, that might eventually expire.)

Probable cause: Wrong/Old credentials.
Solution: Look in the "identity" shared folder for a email by the institution in question.

Log:

Caused by: org.hibernate.exception.SQLGrammarException: could not extract ResultSet
Caused by: java.sql.SQLSyntaxErrorException: Table '...' doesn't exist

Probable cause: non mysql8 database, probably mysql5, might require older connectors and hibernate version.
Solution: Comment the mysql8-connector in pom.xml and uncomment the mysql5-connector. Also comment the hibernate5 version while uncommenting the hibernate4.3.11 version. The result will look something like this:

    <properties>
        <maven.compiler.source>11</maven.compiler.source>
        <maven.compiler.target>11</maven.compiler.target>
        <!--<hibernate.version>5.6.7.Final</hibernate.version>-->
        <hibernate.version>4.3.11.Final</hibernate.version>
    </properties>
    .
    .
    .
   <!--<dependency>
            <groupId>mysql</groupId>
            <artifactId>mysql-connector-java</artifactId>
            <version>8.0.17</version>
        </dependency>-->
   <dependency>
        <groupId>mysql</groupId>
        <artifactId>mysql-connector-java</artifactId>
        <version>5.1.46</version>
   </dependency>

Log:

(uLookup)
Caused by: java.sql.SQLException: Access denied for user 'username'@'connection_url' (using password: YES)
(dbeaver)
Access denied for user 'username'@'connection_url' (using password: YES)

Probable cause: Too many failed requests have locked us out of the View's firewall.
Solution: Contact the Database's Admin and ask him to flush the View's hosts so we can try again.

Log:

Caused by: javax.net.ssl.SSLHandshakeException: The server selected protocol version TLS10 is not accepted by client preferences [TLS13, TLS12]

Probable cause: TLSv1 algorithm is disabled while connecting to an older database.
Solution: Find file /usr/lib/jvm/java-11-openjdk-amd64/conf/security/java.security, go to jdk.tls.disabledAlgorithms and delete TLSv1 from the list. The end result will look like this:

jdk.tls.disabledAlgorithms=SSLv3, TLSv1.1, RC4, DES, MD5withRSA, \
    DH keySize < 1024, EC keySize < 224, 3DES_EDE_CBC, anon, NULL, \
    include jdk.disabled.namedCurves
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