Connection pool advanced settings
Use this page to specify connection pooling related settings.
Properties-shared partitions, free pool partitions, and free pool distribution table size are properties related to reducing the time a thread needs to wait for a synchronization lock.
Partition support is always enabled. The default values of 0 should be used enabling the connection pool to pick the best values for performance. In some cases where large multiprocessor systems are used, adjusting the partition support properties might help performance.
To view this administrative console page, click Resources > Resource Adapters > resource_adapter > J2C Connection Factories > connection_factory > Connection Pool > Advanced Connection Pool.
Configuration tab
- Number of shared partitions
Number of partitions that are created in each of the shared pools.
Data type integer Default value 0 Range 0 to max int - Number of free pool partitions
Number of partitions that are created in each of the free pools.
Data type integer Default value 0 Range 0 to max int - Free pool distribution table size
The free pool distribution table size is used for better distribution of the Subject and CRI hash values within a hash table to minimize collisions for faster retrieval of a matching free connection.
If there are many incoming requests with varying credentials, this value can help with the distribution of finding a free pool for a connection for that user. Larger values are more common for installations that have many different credentials accessing the resource. Smaller values (1) should be used if the same credentials apply to all incoming requests for the resource.
Data type integer Default value 0 Range 0 to max int - Surge threshold
Number of connections created before surge protection is activated.
Surge protection is designed to prevent overloading of a data source when too many connections are created at the same time. Surge protection is controlled by two properties, surge threshold and surge creation interval.
The surge threshold property specifies the number of connections created before surge protection is activated. After you reach the specified number of connections, you enter surge mode.
The surge creation interval property specifies the amount of time, in seconds, between the creation of connections when in surge mode.
For example, assume the follow settings:
- maxConnections = 50
- surgeThreshold = 10
- surgeCreationInterval = 30 seconds
If the connection pool receives 15 connection requests, 10 connections are created at about the same time. The 11th connection is created 30 seconds after the first 10 connections. The 12th connection is created 30 seconds after the 11th connection. Connections continue to be created every 30 seconds until there are no more new connections needed or you reach the maxConnections value.
Surge connection support starts if the surge threshold is > -1 and the surge creation interval is > 0. The surge threshold property has a default value of -1, which indicates that it is turned off.
wsadmin examples
$AdminControl getAttribute $objectname surgeCreationInterval $AdminControl setAttribute $objectname surgeCreationInterval 30 $AdminControl getAttribute $objectname surgeThreshold $AdminControl setAttribute $objectname surgeThreshold 15
Data type integer Default value -1 Range -1 to max int
Specifies the amount of time between connection creates when you are in surge protection mode.
If the number of connections specified in the surge threshold property have been made, each request for a new connection must wait to be created on the surge creation interval. This property has a default value of 20, which indicates that at least 20 seconds should pass between connections being created. Valid values for this property are any positive integer.
Data type integer Default value 20 Range 0 to max int
A stuck connection is an active connection that is not responding or returning to the connection pool. If the pool appears to be stuck (you have reached the stuck threshold), a resource exception is given to all new connection requests until the pool is unstuck. The stuck timer time property is the interval for the timer. This is how often the connection pool checks for stuck connections. The default value is 5 seconds.
If an attempt to change the stuck time, stuck timer time, or stuck threshold properties using the wsadmin scripting tool fails, an IllegalState exception occurs. The pool cannot have any active requests or active connections during this request. For the stuck connection support to start, all three stuck property values must be greater than 0 and maximum connections must be greater than 0.
Also, the stuck timer time, if it is set, must be less than the stuck time value. In fact, it is suggested that the stuck timer time should be one-quarter to one-sixth the value of stuck time so that the connection pool checks for stuck connections 4 to 6 times before a connection is declared stuck. This reduces the likelihood of false positives
wsadmin examples
$AdminControl getAttribute $objectname stuckTime $AdminControl setAttribute $objectname stuckTime 30 $AdminControl getAttribute $objectname stuckTimerTime $AdminControl setAttribute $objectname stuckTimerTime 15 $AdminControl getAttribute $objectname stuckThreshold $AdminControl setAttribute $objectname stuckThreshold 10
Data type integer Default value 5 Range 0 to max int
A stuck connection is an active connection that is not responding or returning to the connection pool. If the pool appears to be stuck (you have reached the stuck threshold), a resource exception is given to all new connection requests until the pool is unstuck. The stuck time property is the interval, in seconds, allowed for a single active connection to be in use to the backend resource before it is considered to be stuck.
Data type integer Default value 0 Range 0 to max int
A stuck connection is an active connection that is not responding or returning to the connection pool. If the pool appears to be stuck (you have reached the stuck threshold), a resource exception is given to all new connection requests until the pool is unstuck. An application can explicitly catch this exception and continue processing. The pool will continue to periodically check for stuck connections when the number of stuck connections is past the threshold. If the number of stuck connections drops below the stuck threshold, the pool will detect this during its periodic checks and enable the pool to begin servicing requests again. The stuck threshold is the number of connections that need to be considered stuck for the pool to be in stuck mode.
Data type integer Default value 0 Range 0 to max int