I have been using Firebird since inception and before that Interbase for
a long time. I am running Linux - Fedora 18 fully patched and have
several web applications that have been running quite a while.

Recently I changed my startup script to use the user/group "tomcat"
instead of root and made changes to systemctl to start tomcat when the
machine boots. All worked on my development machine, but to make sure I
could reproduce what I had done, I brought a second older machine up to
revision and tried the same thing (all software the same, also 64bit).

When I bring tomcat up, it goes NUTS - the log file just grows.

Here is a pruned version of the tomcat log file showing one instance of
the failure with one application:

----
INFO: Deploying configuration
descriptor /opt/apache-tomcat-7.0.35/conf/Catalina/localhost/ledger.xml
Dec 22, 2013 11:49:55 AM org.apache.naming.NamingContext lookup
WARNING: Unexpected exception resolving reference
org.firebirdsql.jdbc.FBSQLException: GDS Exception. 335544721. Unable to
complete network request to host "localhost".
at
org.firebirdsql.jdbc.FBDataSource.getConnection(FBDataSource.java:123)
at
org.firebirdsql.jdbc.AbstractDriver.connect(AbstractDriver.java:126)
at
org.apache.tomcat.jdbc.pool.PooledConnection.connectUsingDriver(PooledConnection.java:278)
at
org.apache.tomcat.jdbc.pool.PooledConnection.connect(PooledConnection.java:182)
...

ledger @ 12/22/2013 11:49:55 Thread:18 : GDS Exception. 335544721.
Unable to complete network request to host "localhost".
java.lang.Exception
at rainbow.IsUti.debugStackTrace(IsUti.java:557)
at rainbow.IsUti.forceStackTrace(IsUti.java:561)
at rainbow.IsUtil.getDBConnection(IsUtil.java:126)
at
rainbow.servlet.RunApplication.initializeBeanGlobals(RunApplication.java:41)
at rainbow.servlet.RunApplication.run(RunApplication.java:123)
at java.lang.Thread.run(Thread.java:744)
...

------

I was using jaybird 2.2.3 and tried 2.2.4 - NO change.

There are proper entries for localhost and the actual host in /etc/hosts
- files are identical for both machines except loghost is added to the
correct one below locally after the true hostname.

127.0.0.1 localhost localhost.rainbow
::1 localhost localhost.rainbow
rainbow 192.168.101.101
hapi 192.168.101.102

I changed the firewall (should not matter, but ...) to allow both
machines to access databases on the other machine (port 3050, of
course). I am able to open databases on either machine from the other
using the hostname or IP; and on BOTH machines I can open a database
locally using
isql localhost:/path_to_db

The path to the DB is the same as listed in the web xml files in
conf/Catalina/localhost (works on one machine); the entire tomcat
directory is a clone; databases are local to each machine (copies for
testing); both machines have tomcat as a member of group firebird; I
have connected to both machines as "tomcat" (su; su tomcat; ...) and if
using the proper isc_username/isc_password on the command line (same as
in xml files) - I can do SQL and see data.

There is a long dissertation by Dimitri on this on the net, but my
Russian is not so good (I stop at the first letter), so perhaps it is
solved.

As an OLD unix / Interbase/Firebird hand, I have already pulled out most
of my hair. This one makes NO sense.

I have tried every trick I know and failed.
Not a good way to start holiday festivities.