What are the benefits of the new features of DB2 V9.5?

We are going to discuss with you the new features of DB2 V9.5 today. We all know that there is a new feature in the DB2 V9.5 database, that is, both MAX_CONNECTIONS and MAX_COORDAGENTS can be set to AUTOMATIC.

If you think the system can withstand all the connections and want to limit the resources consumed by the Coordination proxy, you can set MAX_CONNECTIONS to AUTOMATIC and MAX_COORDAGENTS to a value.

In this case, the system considers that the number of connections to the instance is unlimited. If you do not want to limit the maximum number of connections or the number of coordinated proxies, you can set them to AUTOMATIC. If the value of MAX_CONNECTIONS set to AUTOMATIC is greater than that of MAX_COORDAGENTS set to AUTOMATIC, the connection concentrator is activated.

Then, the server uses the ratio of the two values as a reference (this is called the concentration rate) to adjust the coordination proxy based on the number of connections. Example:

 
 

  
  
db2 update dbm cfg using MAX_CONNECTIONS 300 AUTOMATIC;   
  
  
db2 update dbm cfg using MAX_COORDAGENTS 100 AUTOMATIC; 
 
 

At this time, the concentration rate is 300/100 = 3. When the connection is between 1 and 100, a coordination proxy is created. If the connection is greater than 100 and less than 301, a new coordination proxy is not created. Then, from 301 to 400, 100 coordination agents will be added. When the number is greater than 400 and less than 601, the agent will be stopped ...... That is, 300 coordination proxies are added for every 100 connections added. The current value can be obtained through db2 attach to instance_name and db2 get dbm cfg show detail. The following two cases can be set to AUTOMATIC:

MAX_CONNECTIONS and MAX_COORDAGENTS are set values.

Both MAX_CONNECTIONS and MAX_COORDAGENTS are set to AUTOMATIC.

Of course, the connection concentrator also has some limitations:

The federated database does not support the connection concentrator.

The connection concentrator is invalid for applications that use withhold feature.

The global temporary table must be explicitly closed when the transaction is completed, otherwise the connection concentrator will be closed.

The two-phase transaction commit connection can only be used to connect the two-phase transaction commit connection. Similarly, the connection to the one-phase transaction commit connection can only be used to connect the one-phase transaction commit connection.

The connection concentrator cannot be activated online, that is, the instance must be restarted to take effect.

If you do not want to use the connection concentrator or limit the number of database connections, run the following command:

 
 

  
  
db2 update dbm cfg using MAX_COORDAGENTS AUTOMATIC;   
  
  
db2 update dbm cfg using MAX_CONNECTIONS AUTOMATIC; 
 
 

The above content is an introduction to the new features of DB2 V9.5, and I hope you will get some benefits.

The above content is a description of the new features of DB2 V9.5, hoping to help you in this regard.