6.6.4 DB Connector settings
When using the database session failover functionality, create a new DB Connector apart from the one used in an application. You need to create one DB Connector for each J2EE server. Use the same DB Connector for all applications that use the database session failover functionality.
For details on the procedures from importing to starting a DB Connector, see 4.2 Settings for connecting to the database in the uCosminexus Application Server Application Setup Guide.
This section describes the following settings required for DB Connector to be used in the database session failover functionality:
-
Specifying the transaction support level
-
Specifying an optional name of DB Connector
-
Environment settings of DB Connector
- Organization of this subsection
(1) Setting transaction support level
With the database session failover functionality, you must set transaction support levels. Specify NoTransaction in the <transaction-support> tag under the <hitachi-connector-property>-<resourceadapter>-<outbound-resourceadapter> tag in the Connector property file.
(2) Specifying optional name of DB Connector
With the database session failover functionality, you must specify an optional name for DB Connector. By default COSMINEXUS_SFO_DBCONNECTOR is specified as the optional name for DB Connector.
If you want to change the name to be specified from the default name, specify any name in the <optional-name> tag under the <hitachi-connector-property>-<resourceadapter>-<outbound-resourceadapter>-<connection-definition>-<connector-runtime>-<resource-external-property> tag in Connector property file. For details on specifying optional name of DB Connector, see 2.6 Assigning optional name to Enterprise Bean or J2EE server (user-specified name space functionality) in the uCosminexus Application Server Common Container Functionality Guide.
You must also change the optional name of DB Connector to be defined in a J2EE server to the same value. For details on specifying the optional name of DB Connector for J2EE servers, see 6.6.1 J2EE server settings.
(3) Environment settings of DB Connector
The database session failover functionality is used for implementing 24-hour continuous operation. In order to ensure that there is no impact on the system even if a failure occurs in a database, you must perform settings such as connection failure detection for implementing continuous operation. Consider the time required for recovery and set the value.
For details on connection failure detection, see 3.15.1 Detecting a connection failure in the uCosminexus Application Server Common Container Functionality Guide.
For details on properties to be set in DB Connector and setting methods, see 4.2.2 Defining the DB Connector properties in the uCosminexus Application Server Application Setup Guide.
This subsection describes the properties required to be set in a DB Connector.
(a) Properties to be set in <config-property> tag
This subsection describes the properties set in the <config-property> tag for each database used. Settings of the database session failover functionality are not required for the properties that are not described in this section.
- Important note
-
If you want to use the database session failover functionality, you must set statement pooling. Statement pooling greatly affects memory usage of J2EE servers. Therefore, consider the connection pooling settings also and determine the value to be specified in the PreparedStatementPoolSize property.
For details on statement pooling, see 3.14.4 Statement pooling in the uCosminexus Application Server Common Container Functionality Guide. For details on connection pooling, see 3.14.1 Connection pooling in the uCosminexus Application Server Common Container Functionality Guide. For details on the values that you can specify in PreparedStatementPoolSize, see 4.1.10 Properties that you can specify in the <config-property> tag set up for DB Connector in the uCosminexus Application Server Application and Resource Definition Reference Guide. For details on memory size to be used per statement, see JDBC related documents.
•Properties to be set when using HiRDB
The following table describes properties to be set when using HiRDB.
|
Value to be specified in the <config-property-name> tag |
Value to be specified in the <config-property-type> tag |
Contents or value to be specified in the <config-property-value> tag |
Mandatory/Optional |
|---|---|---|---|
|
description |
java.lang.String |
Specify connection addition information required for connecting to a database. |
Mandatory |
|
DBHostName |
java.lang.String |
Specify host name of HiRDB to be connected. |
Mandatory |
|
loginTimeout |
java.lang.Integer |
Specify maximum waiting time (seconds) for establishing physical connection with HiRDB server when acquiring Connection objects by using the getConnection method. |
Optional |
|
LONGVARBINARY_Access |
java.lang.String |
Specify LOCATOR. |
Mandatory |
|
PreparedStatementPoolSize |
java.lang.Integer |
Specify the numeric value determined by 30 × number-of-Web-applications -on-a-J2EE-server-that-use -the-database-session-failover -functionality. |
Mandatory |
|
CancelStatement |
java.lang.Boolean |
Specify true. |
Mandatory |
|
logLevel |
java.lang.String |
Specify any level for the levels of log trace output by DB Connector. |
Optional |
- Legend:
-
Mandatory: Must be specified
Optional: Specify if required
- Important note
-
To use the database session failover functionality, specify the following values in the client environment definition:
Environment variable name
Value
PDISLLVL
2
PDFORUPDATEEXLOCK
NO
PDDBLOG
ALL
- •Properties to be set when using Oracle
-
The following table describes properties to be set when using Oracle.
Table 6‒48: Properties to be set when using Oracle Value to be specified in the <config-property-name> tag
Value to be specified in the <config-property-type> tag
Contents or value to be specified in the <config-property-value> tag
Mandatory/Optional
databaseName
java.lang.String
Specify a specific database name (SID) on Oracle server.
Mandatory#
serverName
java.lang.String
Specify host name or IP address of Oracle server.
Mandatory#
portNumber
java.lang.Integer
Specify a port number that listens to requests from Oracle server.
Mandatory#
url
java.lang.String
Specify JDBC URL required by Oracle JDBC Thin Driver for connecting to a database.
Mandatory#
loginTimeout
java.lang.Integer
Specify a timeout (units seconds) for connection trial to database.
Optional
PreparedStatementPoolSize
java.lang.Integer
Specify the numeric value determined by 30 × <number of Web applications on a J2EE server that uses the database session failover functionality>.
Mandatory
logLevel
java.lang.String
Specify any level for the levels of log trace output by DB Connector.
Optional
- Legend:
-
Mandatory: Must be specified
Optional: Specify if required
- #
-
Specify all values of databaseName, serverName, and portNumber, or specify the value of url.
(b) Properties to be specified in <property> tag
The following table describes the properties to be set in the <property> tag. Settings of the database session failover functionality are not required for the properties that are not described in this section.
|
Value to be specified in the <property-name> tag |
Value to be specified in the <property-type> tag |
Value of the <property-default-value> tag |
Contents or value to be specified in the <property-value> tag |
Mandatory/Optional |
|---|---|---|---|---|
|
MaxPoolSize |
int |
10 |
Specify maximum value of connection pool#1. |
Mandatory |
|
MinPoolSize |
int |
10 |
Specify minimum value of connection pool#1. |
Mandatory |
|
LogEnabled |
boolean |
true |
Specify true. |
Mandatory |
|
User#2 |
String |
-- |
Specify a user name. |
Mandatory |
|
Password |
String |
-- |
Specify a password. |
Mandatory |
|
ValidationType |
int |
1 |
Specify 1. |
Mandatory |
|
RetryCount |
int |
0 |
Specify connection acquisition retry count. Specify a value, in accordance with the database settings and network environment that enables recovery of a database when a failure occurs. |
Optional |
|
RetryInterval |
int |
10 |
Specify connection acquisition retry interval. Specify a value, in accordance with the database settings and network environment that enables recovery of a database when a failure occurs. |
Optional |
|
RequestQueueEnable |
boolean |
true |
Specify true. |
Mandatory#3 |
|
RequestQueueTimeout |
int |
30 |
Specify maximum value that can stop the queue waiting for connection acquisition when connections exhaust.#4 |
Mandatory#3 |
|
WatchEnabled |
boolean |
true |
Specify whether you want to enable connection pool monitoring. |
Optional |
|
WatchInterval |
int |
30 |
Specify connection pool monitoring interval. |
Optional |
|
WatchThreshold |
int |
80 |
Specify threshold value that monitors connection pool use status. |
Optional |
|
WatchWriteFileEnabled |
boolean |
true |
Specify true. |
Optional |
- Legend:
-
Mandatory: Must be specified
Optional: Specify if required
--: None
- #1
-
Calculate the value of the connection pool by using the formulas given below. Set the same value as the maximum and minimum value of the connection pool.
- If you set number of concurrent execution threads in Web application unit or URL unit:
-
Sum of number of concurrent execution threads in a Web application that uses the database session failover functionality on a J2EE server + 2
- If you set number of concurrent execution threads in J2EE server unit,
-
Number of concurrent execution threads in J2EE server + 2
If a J2EE server receives requests exceeding the maximum value of connection pools, those requests go to the state of waiting in a queue for acquiring connection, when connections exhaust.
- #2
-
Register the creator of the table in the user set in DB Connector.
- #3
-
These settings are not required if the functionality that controls the number of concurrent execution threads in the Web application unit, is disabled.
- #4
-
Specify a value in the following range.
- If Web server integration is used:
-
1 < RequestQueueTimeout < Timeout value for data reception from the web container that is set in the reverse proxy
In the preceding expression, Timeout value for data reception from the web container that is set in the reverse proxy is the value specified for the timeout key in the ProxyPass directive or the value specified in the Timeout directive.
- If requests are directly exchanged with the J2EE server and not via a web server:
-
1 < RequestQueueTimeout