I. Overview
1. version
| Report server version | Function changes |
|---|---|
| 10.0.18 |
|
| 10.0.19 | Decision-making platform adaptation fetchsize configuration |
2. Function introduction
This article will introduce the advanced setting method and the meaning of each parameter in its properties.
connection pool
fetchsize
II. Specific introduction
1. Advanced settings
Click Server>Define Data Connection in FineReport Designer, select a data connection, and click Advanced Settings to set connection pool attributes, and some data connections can also set fetchsize. As shown below:
2. Introduction to connection pool attribute parameters
The description of each parameter of the connection pool attribute is shown in the following table:
| Name | Example | Meaning |
|---|---|---|
| Initialize Connections | initialSize="1" | Number of initial connections created when the connection pool is started |
| Maximum Acitive Connections | initialSize="1" | The maximum number of active connections that the connection pool can allocate at the same time, if it is set to a non-positive number, it means no limit |
| Maximum Idle Connections | maxIdle="100" | Note: This parameter is obsolete |
| Minimum Idle Connections | minIdle="2" | The minimum number of connections that are allowed to remain idle in the connection pool. New connections will be created below this number. If set to 0, no connections will be created. |
| Maximum Waiting Time(ms) | maxWait="1000" | When there is no available connection, the maximum time (counted in milliseconds) for the connection pool to wait for the connection to be returned. If the time is exceeded, an exception will be thrown. If set to -1, it means infinite waiting |
| SQL Validation Query | validationQuery="SQL语句" | It is used to validate the connection taken from the connection pool. If specified before returning the connection to the caller, the query must be a SQL SELECT and must return at least one row of records. |
| Test before Getting Connections | testOnBorrow="false" | Indicate whether to check before removing the connection from the pool, if the check fails, remove the connection from the pool and try to remove another. |
| Test before Returning Connections | testOnReturn="true" | Indicate whether to inspect before returning to the pool |
| Open Idle Connection Recyclers Test | testWhileIdle="true" | Indicate whether the connection is checked by the idle connection collector (if any), if the check fails, the connection will be removed from the pool. |
| Sleep Time of Idle Connections Recyclers(ms) | timeBetweenEvictionRunsMilli s="1000 | The sleep time value during the running of the idle connection collector thread, in milliseconds. If set to a non-positive number, the idle connection collector thread will not run. |
| Recycled and Tested Idle Connections | numTestsPerEvictionRun="2" | The number of connections checked each time the idle connection collector thread (if any) runs |
| Keep Minimum Idle Time Value(s) | minEvictableIdleTimeMilli s="18005000" | The minimum time value for the connection to remain idle in the pool without being reclaimed by the idle connection collector thread (if any). |
The maximum number of active connections is set to exceed the number of connections in the database. It can only be based on the number of connections in the database. If you want to adjust it to the maximum, you must also adjust the number of connections in the database. Refer to the solution in the document Connection Pool Full Problem.
3. fetchsize setting
When executing a SQL query statement, you need to open a cursor on both the client and the server, and apply for a memory space respectively as a buffer for storing the query data. How many pieces of data are stored in this memory area is determined by fetchsize.
Users can set fetchsize for "Oracle, DB2, Postgre" data connection in FineReport. You can enter any value from 1 to 1,000,000. If it is blank, it means that this parameter is not configured.
Note: In 10.0.19, the decision-making platform adds the setting item of fetchsize. When configuring fetchsize remotely, the designer used must be version 10.0.18 or higher, otherwise the fetchsize setting item in the platform will disappear if the save is triggered in the designer.
III. Matters needing attention
If when accessing the template, the connection timeout and waiting status are reported, and the warning is as follows:
Warning: Cannot get a connection, pool error Timeout waiting for idle object
at com.fr.third.org.apache.commons.dbcp.PoolingDataSource.getConnection(PoolingDataSource.java:114)
at com.fr.third.org.apache.commons.dbcp.BasicDataSource.getConnection(BasicDataSource.java:1044)
at com.fr.data.pool.MemoryConnection.create(Unknown Source)
at com.fr.data.impl.JDBCDatabaseConnection.createConnection(Unknown Source)
You need to increase the corresponding number of connections.
