Configuring database connection resilience feature

Many times a collaboration is critical to the success of an enterprise. In these cases, the availability of databases involved in the collaboration is crucial. However, there may be occasions when the databases may be unavailable for periods of time (for example, database failover or routine maintenance). The database connection resilience feature provides protection against these temporary periods of when a database may be unavailable. The following sections describe what is involved to insure critical databases are available to your collaborations. Note that database connection resilience does not directly affect collaboration design.

Customizing the database connection resilience feature

To customize the database connection resilience feature, in the InterChange Server.cfg file, you can set the DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL properties for each database used by InterChange Server for event managment, transactions, repository, flow monitoring, relationships, and user registry:

The global default properties for all of the databases that use these properties are defined in the DB_CONNECTIVITY section of the file.

You can set defaults for DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL for individual databases in the sections of the InterchangeServer.cfg file shown in Table 26. Configuring defaults for the databases separately provides flexibility when the system attempts to reconnect to the databases.

Table 26. Sections of InterchangeSystem.cfg to set database resilience defaults

Section Database
EVENT_MANAGEMENT Event management
FLOW_MONITORING Flow monitoring
REPOSITORY Repository
TRANSACTIONS Transactions
USER_REGISTRY User registry

Note:
You can configure the defaults for the relationships database only in the DB_CONNECTIVITY section of the InterchangeSystem.cfg file.

Set the DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL properties in the Server Configuration in System Manager. These properties are set to their default values even if they are not defined in the InterchangeSystem.cfg file. To customize the properties:

  1. Connect to InterChange Server using System Manager.
  2. Open the Server Configuration in the System Manager.
  3. Set the DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL properties.
  4. Save the changes.
  5. Restart InterChange Server.

Set the DB_CONNECT_INTERVAL property to a value that is neither too small nor too large. If the value is too large, for example 10 minutes, after one unsuccessful attempt to recover database connections, the next attempt begins after ten minutes even though the database may become available one minute later. If the value is too small, for example 2 seconds, in that same 1-minute period InterChange Server attempts to recover the database connection 30 times, and all attempts fail.

If scheduled database outages cause a cold restart of the database, set DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL to values that can accommodate the outage, if it is known. Setting the propperties to account for the downtime prevents unnecessary recovery attempts.

Two other properties relate to database connection resilience for all user databases: maxConnectRetries and maxConnectRetryInterval. These properties are defined in each user-defined database connection. These properties work the same as DB_CONNECT_RETRIES and DB_CONNECT_INTERVAL and cause InterChange Server to attempt to reconnect to user databases as it does for the system databases. To configure these properties:

  1. Open System Manager.
  2. Open or create a database connection.
  3. Set the maxConnectRetries and maxConnectRetryInterval properties.
  4. Save the user database connection.
  5. Deploy the user database connection to InterChange Server.

Default settings for database connection resilience

After InterChange Serveer installation, the default value of DB_CONNECT_RETRIES is 3 and the value for DB_CONNECT_INTERVAL is 60 seconds. You can change these defaults by editing the property values in the DB_CONNECTIVITY section of the InterchangeSystem.cfg file. You can also set the values in the Database Connectivity dialog of System Manager (see Figure 26).

Figure 26. System Manager showing default values for database resilience


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