Extra Port(s) for Mirror DB

[Former Member]

I'm using SQL ANywhere 12.

I have set up a mirror DB and I would like to access it by using the server name (primaries) on both Mobilink and Tomcat (jcon 3). I can access the DB by server name no problem when the firewalls are disabled. however as soon as I turn on the firewalls (I already have exclusions for the server/mobilink ports 2638/2439), I can only access my mirror DB by specifying full URLs:

For example, with Firewalls off, I can use: - Tomcat: url="jdbc:sybase:Tds:asdf?ALTERNATE_SERVER_NAME=primaries - Mobilink (ODBC): I just enter user/pass and server name (primaries)

However, if I enabled Firewalls, I have to speficy both DB servers URLs to connect: - Tomcat: url="jdbc:sybase:Tds:DB1_URL:2638,DB2_URL:2638" - Mobilink (ODBC): I have to enter user/pass, host (DB1_URL:2638,DB2_URL:2638)

Generally, I don't mind, however, in the case of Tomcat, I find that if both DBs are up and DB_1 is the mirror, then Tomcat will always connect to it, and since DB_1 is mirror, access is read-only causing issues when I try to do DB updates. Thus, I would like to know why when my firewalls are up, the use of the 'server name' does not work (I presume it is because I'm missing extra ports I have to open).

Thanks.

[VolkerBarth]

Do you need to use jConnect or would the SQL Anywhere JDBC driver do, as well? I guess the latter is easier to configure for HA setups as it can use the common SQL Anywhere connection parameters, i.e. those used in the HA samples.

[Former Member]

Hi Volker, I would like to keep using the jconn3 driver if possible to minimize changes on my current setup

[VolkerBarth]

I do not use jConnect myself, but if you use the alternate server name (which is of course very reasonable in a HA setup!) , AFAIK host and port info is ignored, and an UDP broadcast is needed to locate the according server. I guess your firewall does block that broadcast...

Note, that is just wild guessing...

[Former Member]

Sorry for the late reply. Got sidetracked with other project stuff, So Volker, by chance, do you know which UDP port this is?

[VolkerBarth]

AFAIK it uses the same ports for UDP as for TCP, by default 2638. On Windows, you can check via netstat -a -b -p UDP and look for the dbsrv12.exe.

Still I think using the SA JDBC driver would prevent the need to use broadcasts...