I'm setting up a new Tomcat 8 server and configuring the database resource
connections.
I'm running Tomcat 8 on JDK 8 (1.8.0_45) and using ojdbc7.jar (or
ojdbc7_g.jar).
The oracle server is: Oracle Database 11g Enterprise Edition Release
11.2.0.3.0 - 64bit Production
It's a RAC configuration with 3 nodes in the cluster.
I have the following Resource entry:
<Resource
name="datasource"
auth="Container"
type="javax.sql.DataSource"
factory="org.apache.tomcat.jdbc.pool.DataSourceFactory"
driverClassName="oracle.jdbc.OracleDriver"
defaultAutoCommit="false"
testWhileIdle="false"
testOnBorrow="false"
testOnReturn="false"
validationQuery="SELECT 1 FROM DUAL"
validationInterval="30000"
timeBetweenEvictionRunsMillis="5000"
minEvictableIdleTimeMillis="30000"
initialSize="35"
maxActive="100"
minIdle="35"
maxIdle="100"
maxWait="300000"
removeAbandoned="true"
removeAbandonedTimeout="60"
logAbandoned="true"
jmxEnabled="true"
username="username"
password="password"
url="jdbc:oracle:thin:@
(DESCRIPTION=
(ADDRESS_LIST=
(LOAD_BALANCE=ON)
(ADDRESS=(PROTOCOL=TCP)(HOST=host1)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=host2)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=host3)(PORT=1521))
)
(CONNECT_DATA=(SERVICE_NAME=servname))
)"
/>
One of my questions has to do with the url setting. As you can see, I'm
using a TN-like string to list all three nodes.
Have I put the LOAD_BALANCE setting in the correct place?
The intention is that the driver sends queries to each node instead of
sending all of the queries to a single node.
Is there any way for me to verify that it's working? i.e., can I see what
host the driver is connected to for sending a query?
I cranked up debugging on the driver and see a host name associated with a
AUTH_SC_SERVER_HOST property but I only see that when the connection pool
is being initialized. When I send a query I no longer see a host
information.
I've also read a bit about the (FAILOVER=ON) setting and am unsure if it's
supported or what it will do.
If I change the connection string to:
url="jdbc:oracle:thin:@
(DESCRIPTION=
(ADDRESS_LIST=
(LOAD_BALANCE=ON)
(FAILOVER=ON)
(ADDRESS=(PROTOCOL=TCP)(HOST=host1)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=host2)(PORT=1521))
(ADDRESS=(PROTOCOL=TCP)(HOST=host3)(PORT=1521))
)
(CONNECT_DATA=(SERVICE_NAME=servname))
)"
What will adding the FAILOVER part do?
If a RAC node goes down and then comes back, will the driver recover and
start sending queries to that node again?
Thanks,
Kevin.
